CA2809478A1 - Luminescent compounds and methods of using same - Google Patents

Abstract

The invention provides compounds that are photoluminescent and electroluminescent, which may emit intense light. The invention further provides methods of producing photoluminescence and electroluminescence, methods of applying the compounds in thin films, and uses of the compounds of the invention in luminescent probes, sensors and electroluminescent devices.

Description

LUMINESCENT COMPOUNDS
., AND METHODS OF USING SAME
FIELD OF THE INVENTION
The invention relates to compounds having luminescent (e.g., fluorescent, phosphorescent) properties, and to methods of using such compounds. The invention more particularly relates to compounds having photoluminescent and/or electroluminescent properties, and to uses of same. The invention also relates to compounds having photo-receptor properties due to their ability to separate charges. The invention also relates to compounds having photon harvesting properties.
BACKGROUND OF THE INVENTION
Bright and efficient organic light-emitting diode (OLED) devices and electroluminescent (EL) devices have attracted considerable interest due to their potential application for flat panel displays (e.g., television and computer monitors) and lighting. OLED based displays offer advantages over the traditional liquid crystal displays, such as: wide viewing angle, fast response, lower power consumption, and lower cost. However, several challenges still must be addressed before OLEDs become truly affordable and attractive next generation display and lighting. To realize white lighting and other full color display applications, it is essential to have the three fundamental colors of red, green, and blue provided by emitters with sufficient color purity and sufficiently high emission efficiency.
Phosphorescent Organic Light-Emitting Diodes (PhOLEDs) have recently received much attention because of their high energy efficiency for next generation flat panel displays and solid state lighting devices. OLEDs based on phosphorescent emitters can have three to four-fold higher device quantum efficiencies than those based on fluorescent emitters.
The key challenge in PhOLEDs research is the development of phosphorescent metal complexes with high quantum efficiency and high stability, especially blue phosphorescent compounds. Earlier research efforts on phosphorescent materials for OLEDs focused on 2-phenylpyridine(Hppy)-based Ir(111) complexes because of their high photoluminescent quantum efficiencies . Although some efficient PhOLEDs based on Ir(111) emitters have been achieved, stable blue PhOLEDs based on 1r(111) compounds remain elusive. Blue phosphorescent compounds are among the most sought-after materials by industry around the world as one of the key color components for electroluminescent devices.
SUMMARY OF THE INVENTION
An aspect of the invention provides a compound having general formula (100):
Rh Rk B h _______________ X
1 _________________________________________________ X 2 /
Rm ________________________________________ Pt \
Y
Rp wherein B is sterically sheltered and is located on ring 1 either para or meta to the C-Pt bond, R is a non-aromatic carbocycle or heterocycle that is attached as a fused ring or as a substituent, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, B(R')2, BR'(ary1), B(aryl)2, aryl-B(aryl)2, 0, NR', OR', a nitrile group, C(halo)3which is optionally CF3, or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched, cyclic, or any combination thereof, k, p and h are independently 0 to 5 and m and j are independently 0 to 3, and k, h and m are not all 0, with the proviso that there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack on the B, and wherein if there is only one substituent that is ortho to B, then that substituent is branched C3, branched C4, or linear or _ branched C5-or higher, t is 0 or 1, a dotted line in a ring indicates that the ring can be saturated, unsaturated, aromatic, or non-aromatic, X is independently C or N and at least two X are N; and Y is independently N or 0, wherein a substituent can be further substituted.
In an embodiment of this aspect the compound of general formula 100 comprises at least two C1 substituents which are both are located ortho to the boron.
In an embodiment of this aspect, the invention provides compounds that are photoluminescent or electroluminescent.
In an embodiment of this aspect, the compound of general formula 100 is a compound of general formula 101:
Ri (Mes)2B // ____ AX v 1 _______________________________________________ c ,.T X
\,....,, RI( \ - X ------ X
Pt7 / - - -\
Yir 3 %.,Y
, , I
lo RP
t wherein R, m, j, p, t, X and Y are defined previously, and Mes is mesityl.
In an embodiment of this aspect, Y is oxygen. In an embodiment of this aspect, the at least two X that are N are three X that are N, so that ring 2 is a triazole.
In another embodiment of this aspect, the compound is BC1 or BC2. In another embodiment of this aspect, the compound is a Pt(II) complex of Table 1. In an embodiment of this aspect, the compound is C5, BC1-acac, BC1-nacnac, BC2-acac, or BC2-nacnac, Pt-12, 51, or 52.

In another aspect the invention provides, the invention provides a compound of general formula Rh Rk (-4)13/X7- xy,J
______________________________________________ x 2 I
Rnr ____________________________________________ X 200 wherein B is sterically sheltered and is located on ring 1 either para or meta to the C-Pt bond, R is a non-aromatic carbocycle or heterocycle that is attached as a fused ring or as a substituent, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, B(R')2, BR'(ary1), B(aryl)2, aryl-B(aryl)2, 0, NR)2, OR', a nitrile group, C(halo)3which is optionally CF3, or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched, cyclic, or any combination thereof, k and h are independently 0 to 5 and m and j are independently 0 to 3, and k, h and m are not all 0, with the proviso that there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack on the B, and wherein if there is only one substituent that is ortho to B, then that substituent is branched C3, branched C4, or linear or branched C5-or higher, t is 0 or 1, a dotted line in a ring indicates that the ring can be saturated, unsaturated, aromatic, or non-aromatic, X is independently C or N and at least two X are N; and Y is independently N or 0. In an embodiment of this aspect, the compound is photoluminescent or electroluminescent.
In an embodiment of this aspect, the compound is B-NHC1, B-NHC2, B-triazole1, B-triazole2, B-Me-triazole1, B-triazole3, B-triazole4, or B-Me-benzimidazole1.
In another aspect the invention provides, the invention provides a composition comprising a photoluminescent or electroluminescent compound of general formula 100 or 200, an organic polymer, and a solvent.
In another aspect the invention provides a photoluminescent product or an electroluminescent product comprising a compound of the above aspects.
In an embodiment of this aspect, such a product is a flat panel display device or a lighting device. In an embodiment of this aspect, such a product is a luminescent probe or sensor.
In another aspect the invention provides, a method of producing electroluminescence, comprising the steps of: providing an electroluminescent compound of general formula 100 or 200 and applying a voltage across said compound so that said compound electroluminesces.
In another aspect the invention provides, an electroluminescent device for use with an applied voltage, comprising a first electrode, an emitter which is an electroluminescent compound of general formula 100 or 200 optionally in a host layer, and a second, transparent electrode, wherein voltage is applied to the two electrodes to produce an electric field across the emitter so that the emitter electroluminesces.
In another aspect the invention provides, an electroluminescent device for use with an applied voltage, comprising a first electrode, a second, transparent electrode, an electron transport layer adjacent the first electrode, a hole transport layer adjacent the second electrode, and an emitter which is an electroluminescent compound of general formula 100 or 200 optionally in a host layer, interposed between the electron transport layer and the hole transport layer, wherein voltage is applied to the two electrodes to produce an electric field across the emitter so that the emitter electroluminesces.
In another aspect the invention provides, a method of harvesting photons comprising the steps of: providing a compound of general formula 100 or 200, and providing light such that photons strike said compound and charge separation occurs in said compound.
In some embodiments separated charges recombine and photons are released. In an embodiment separated charges migrate to respective electrodes to produce a potential difference.
In another aspect the invention provides, a method of separating charges comprising the steps of: providing a compound of general formula 100 or 200 and providing light such that photons strike said compound and charge separation occurs in said compound. In some embodiments, separated charges recombine and photons are released.
In an embodiment of this aspect, separated charges migrate to respective electrodes to produce a potential difference.
In another aspect the invention provides, a photocopier employing the above method of harvesting photons or the above method of separating charges.
In yet another aspect the invention provides, a photovoltaic device employing the above method of harvesting photons or the above method of separating charges.
In another aspect the invention provides, a photoreceptor employing the above method of harvesting photons or the above method of separating charges.
In another aspect the invention provides, a solar cell employing the above method of harvesting photons or the above method of separating charges.
In another aspect the invention provides, a semiconductor employing the above method of harvesting photons or the above method of separating charges.
In another aspect the invention provides, a light emitting device comprising an anode, a cathode, and an emissive layer, disposed between the anode and the cathode, wherein the emissive layer comprises a compound of general formula 100 or a compound of general formula 200. In another aspect the invention provides, a consumer product comprising such a device.
In another embodiment of this aspect, the device's emissive layer further comprises a host.
In another aspect the invention provides, the invention provides a method of synthesizing a compound of general formula 100, comprising combining in an appropriate solvent to form a reaction mixture (i) a cyclometalating ligand comprising two rings joined by one bond, the first ring being an aromatic or non-aromatic heterocycle that comprises at least one ring heteroatom, and the second ring being an aromatic carbocycle, wherein the first and second rings may be substituted or unsubstituted; and (ii) a charge-neutral platinum(II) compound, wherein at least one Pt(II) is bonded to four monodentate ligands, optionally, allowing reaction to proceed for an appropriate reaction time, adding to the reaction mixture strong acid, optionally, allowing reaction to proceed for an appropriate reaction time, adding to the reaction mixture a stabilizing ligand comprising a bidentate heteroaryl ligand comprising at least two heteroatoms, each heteroatom being available for bonding to the Pt(II), wherein the bidentate heteroaryl ligand may be substituted or unsubstituted; and obtaining a product that is a Pt(II) chelated by two different bidentate ligands wherein the first bidentate ligand is derived from the cyclometalating ligand and the second bidentate ligand is derived from the stabilizing ligand, wherein substituents may be further substituted and comprise a non-aromatic carbocycle or heterocycle, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, BR2, B(aryl)2, aryl-B(aryl)2, 0, NR', OR', a nitrile group, C(halo)3which includes CF3, or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched, cyclic, or any combination thereof.
In an embodiment of this aspect, the amount of cyclometalating ligand and strong acid are equimolar to the amount of Pt(II), and the amount of bidentate ligand is twice as much as the amount of Pt(II). Another embodiment further comprising purifying the product.
In some embodiments, the strong acid is: HBF4, p-toluenesulfonic acid (Ts0H), trifluoroacetic acid (TFA), picolinic acid (PA), or trifluoromethanesulfonic acid (Tf0H). In some embodiments, the -stabilizing ligand is p-diketonato, 1,3-diketiminato, picolinato, or N . In some embodiments, substituents comprise aliphatic, aryl, B(aryl)2, B(aliphatic)(ary1), B(aliphatic)(aliphatic). In certain embodiments, the substituent comprises phenyl, isopropyl, n-butyl, t-butyl, or phenyl-BMes2. In certain embodiments, the stabilizing ligand is added as a solution formed by dissolving a salt form of the stabilizing ligand that comprises a sodium, lithium or potassium counterion. In certain embodiments, the reaction mixture is maintained at ambient temperature and/or pressure. In certain embodiments, the reaction mixture is maintained at about 55 C. In certain embodiments, the product is la, lb, lc, 2a, 2b, 2c, 3, 4, 5, 6, 7, 8a, 8b, 8c, 9a, 9b, 9c, 21, 22, 23, 24, or 25. In certain embodiments, the stabilizing ligand is the conjugate base of the strong acid. In certain embodiments, the strong acid is picolinic acid. Certain embodiments, further comprising adding heat.
In certain embodiments, one or more steps are performed under an inert atmosphere. In certain such embodiments the product is 11. Certain embodiments also comprising cooling. In certain embodiments, the product is BC1, BC2, Pt(B-NHC1)(nacnac), or Pt(B-NHC2)(nacnac).
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example to the accompanying drawings, which illustrate aspects and features according to preferred embodiments of the present invention, and in which:
Figure 1 shows a preferred embodiment of a three layer electroluminescent (EL) display device according to the invention;
Figure 2A shows the absorption (dashed) and emission (solid) spectra of BC1 and BC2 in methylene chloride at a concentration of 1.0 x 10-5 M;
Figure 2B shows a crystal structure schematic for the molecular structure of BC1 with 50% thermal ellipsoids and labeling;
Figure 2C shows a crystal structure schematic for the molecular structure of BC2 with 50% thermal ellipsoids and labeling;
Figure 2D graphically shows current efficiencies for OLEDs based on BC1 and BC2;
Figure 2E graphically shows power efficiencies for OLEDs based on BC1 and BC2;

Figure 2F graphically shows cyclic voltammetry diagrams of BC1 and BC2 recorded in t DMF with NBu4PF6as the electrolyte, scan rate 200 mV/s;
Figure 3A shows the emission spectra of Cl (A); C2 (U); and C3 (0) in PMMA (10 wt%);
Figure 3B shows the emission spectra of C4 (a); C5 (0); and C8 (11I) in PMMA
(10 wt%);
Figure 3C shows the emission spectra of C6 (0); C6 (5%) (A); and C9 (II) in PMMA (10 wt% and 5 wt%, respectively) ;
Figure 3D shows the emission spectra of C10 (0); and C11 (5%)(U) in PMMA (10 wt%
and 5 wt%, respectively) ;
Figure 3E shows the emission spectra of C27 (5%) (III); and C27(0) in PMMA (10 wt%
and 5 wt%, respectively) ;
Figure 3F shows emission spectra of compound C12 in 1 wt%, 5 wt% and 10 wt%
doped PMMA films, respectively, after drying for 1 day;
Figure 4A shows the absorption spectrum of Pt-12 in dichloromethane (concentration=
2.0 x 10-5 M) at room temperature;
Figure 4B shows the emission spectrum of Pt-12 in dichloromethane (c = 2.0x10-5 M) at r.t. under nitrogen;
Figure 5A shows the electrolurninescent spectra of compound C6 doped at 5% in TcTa (tris(4-carbazoy1-9-ylphenyl)amine) host layer; and Figure 5B shows a plot of external quantum efficiency (EQE) versus luminance for compound C6.
DETAILED DESCRIPTION OF THE INVENTION
Definitions As used herein, the term "TfOH" means trifluoromethanesulfonic acid, which is also known as triflic acid or CF3S03H. The term "Ts0H" means p-toluenesulfonic acid. The term "TFA" means trifluoroacetic acid. The term "PA" means picolinic acid.
As used herein, the terms "NAC" chelate, "PAC" chelate and "CAC" chelate are used to indicate what atoms are bonded to the metal. That is, "NAC" indicates that a nitrogen and a carbon are bonded to the metal, "PAC" indicates that a phosphorus and a carbon are bonded to the metal, and "CAC" indicates that a carbon and another carbon are bonded to the metal.
As used herein, the term "chelation" indicates formation or presence of bonds (or other attractive interactions), e.g., coordination bonds, between a single central atom and two or more separate binding sites within the same ligand.

As used herein, the term "cyclometalation" refers to a reaction of transition metal a complexes in which an organic ligand undergoes intramolecular metalation with formation of a metal-carbon sigma bond (Bruce, Michael I., Angewandte Chemie Intl Ed. (2003) 16(2): 73-86).
As used herein "aliphatic" includes alkyl, alkenyl and alkynyl. An aliphatic group may be substituted or unsubstituted. It may be straight chain, branched chain or cyclic.
As used herein "aryl" includes aromatic carbocycles and aromatic heterocycles and may be substituted or unsubstituted.
As used herein, B means boron.
As used herein the term "Mes" means mesityl, which is also known as 2,4,6-trimethylphenyl.
As used herein the term "acac" refers to 8-diketonato. As used herein the term "nacnac"
refers to 8-diketimino. As used herein the term picolinato may appear abbreviated as "pico".
As used herein, the term "unsubstituted" refers to any open valence of an atom being occupied by hydrogen. Also, if an occupant of an open valence position on an atom is not specified then it is hydrogen.
As used herein "substituted" refers to the structure having one or more substituents.
As used herein "heteroatom" means a non-carbon, non-hydrogen atom. In some cases, a heteroatom may have a lone pair of electrons available to form dative or coordinate bonds (e.g., N, 0, P).
As used herein, the term "dative bond" refers to a coordination bond formed when one molecular species serves as a donor and the other as an acceptor of an electron pair to be shared in formation of a complex.
As used herein, the term "monodentate ligand" refers to a moiety that has a single site that is suitable for binding a metal ion. In general, the stability of a metal complex correlates with the denticity of its ligands, where denticity is defined as, "in a coordination entity the number of donor groups from a given ligand attached to the same central atom" (IUPAC
Gold Book). This is thought to be because monodentate ligands are more apt to dissociate from a metal ion than a bidentate or multidentate ligand. This phenomenon is considered to be due to the proximity of the ligand to the metal ion. For example, in solution, when a monodentate ligand dissociates from a metal ion, it drifts away from the metal ion. In contrast, when a bidentate ligand dissociates at one of its two binding sites, the other binding site's bond means that the bidentate ligand remains in the proximity of the metal ion. For this reason, it is likely to reform a bond _ between the available binding site and the metal ion. Thus a bidentate metal complex is more stable than a monodentate metal complex.
Embodiments Compared with Ir(111) complexes, Pt(II) compounds that have a high phosphorescent quantum efficiency are scarce. This scarcity is due to strong intermolecular rc-it stacking interactions caused by Pt(11) complexes' square planar geometry. Such interactions lead to excimer formation and decreases in emission quantum efficiency and color purity in the solid state. The square planar geometry of Pt(II) may have one advantage over Ir(111), namely the access to a higher triplet state. Such access is due to greater ligand field splitting for a given set of chelate ligands, which greatly increases the energy of the d-d state.
Thus, Pt(11) compounds are good candidates for development of blue phosphorescent emitters, if low emission efficiency and intermolecular interaction issues can be addressed.
Several examples of green, orange or red phosphorescent Pt(11) compounds have been demonstrated recently for successful use in PhOLEDs (A. F. Rausch etal., Proc. SPIE 2007, 6655, 66550F/1; B. Ma etal., Adv. Funct. Mater. 2006, 16, 2438; V. Adamovich etal., New J. Chem. 2002, 26, 1171; B. W.
D'Andrade et al.,Adv. Mater. 2002, 14, 1032; J. A. G. Williams etal., Coord.
Chem. Rev. 2008, 252, 2596; W. -Y. Wong etal., Organometallics, 2005, 24, 4079; G. Zhou etal., J. Mater. Chem., 2010, 20, 7472; J. Kavitha et al., Adv. Funct. Mater., 2005, /5, 223; S.-Y.
Chang etal., lnorg.
Chem., 2007, 46, 7064; S.-Y. Chang etal., Dalton Trans., 2008, 6901; Z. M.
Hudson etal., Adv.
Funct Mater. 2010, 20, 3426; Z. M. Hudson etal., Dalton Trans., 2011, 40, 7805; Z. Wang etal., App!. Phys. Lett., 2011, 98, 213301; Z. M. Hudson etal., Chem. Commun., 2011, 47, 755).
Blue PhOLEDs based on Pt(II) compounds are very rare and only a few examples are known in the literature (K. Li, X. Guan etal., Chem. Commun., 2011, 47, 9075;
Y. Unger, etal., Angew. Chem. mt. Ed., 2010, 49, 10214; E. L. Williams etal., Adv. Mater.2007, 19,197; M.
Cocchi, etal., App!. Phys. Lett. 2009, 94, 073309; M. Cocchi, etal., Adv.
Funct. Mater., 2007, 17, 285; X. Yang et al., Adv. Mater. 2008, 20, 2405; S.-Y. Chang et al., Inorg.
Chem. 2007, 46, 11202).
The inventors of this discovery have found that cyclometalated Pt(II) li-diketonate, cyclometalated Pt(II) p-diketiminate, and cyclometalated Pt(II) picolinate complexes, as described herein, have promising PhOLED properties such as photoluminescent quantum efficiencies and may offer one or more of the key color components for electroluminescent devices. General formula 100 representing such cyclometalated Pt(II) P-diketonate, _ cyclometalated Pt(I1)p-diketiminate, and cyclometalated Pt(II) picolinate complexes is shown below:
Rh R.
Rk B 4 ____________ X 1 1 X --RmN ___________ X ------- X
Pt/
Y= 'Y
, I
,,, .. _ , , ............
RP
t wherein B is sterically sheltered and is located on ring 1 either para or meta to the C-Pt bond, R is a non-aromatic carbocycle or heterocycle that is attached as a fused ring or as a substituent, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, B(R)2, BR'(ary1), B(aryl)2, aryl-B(aryl)2, 0, NR', OR', a nitrile group, C(halo)3which is optionally CF3, or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched, cyclic, or any combination thereof (e.g., adamantyl), k, p and h are independently 0 to 5 and m and j are independently 0 to 3, and k, h and m are not all 0, with the proviso that there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack on the B, and wherein if there is only one substituent that is ortho to B, then that substituent is branched C3, branched Ca, or linear or branched C5-or higher, t is 0 or 1, a dotted line in a ring indicates that _ the ring can be saturated, unsaturated, aromatic, or non-aromatic, X is independently C or N and at least two X are N, and Y is independently N or 0. A substituent may be further substituted.
The term "cyclometalation" refers to a reaction of a transition metal complex in which an organic ligand undergoes intramolecular metalation with formation of a metal-carbon sigma bond (Bruce, Michael I., Angewandte Chemie Intl Ed. (2003) 16(2): 73-86). A
cyclometalating ligand is one component of the compounds described and characterized herein.
General structure 200, showing structural features of cyclometalating ligands described herein, is provided below:
Rh Rk 15<- B __________________________ -1>
______ Rm4 _________________________________________________________________ X 'X

wherein R, k, h, m and j are as defined for general formula 100.
Notably, B (boron) is sterically sheltered to protect it from nucleophilic attack, so there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack by, for example, water. If there is only one substituent ortho to B
then that substituent is branched C3, branched C4, or linear or branched C5-or higher. A dotted line in a ring indicates that it can be saturated, unsaturated, aromatic or non-aromatic. A
substituent can be further substituted.
In certain embodiments, compounds of general formula 200 are luminescent (i.e., fluorescent).

_ The cyclometalating ligand has two rings bonded together through one bond so that when this ligand chelates a metal ion, the metal atom becomes part of a newly-formed five- or six-membered ring (see below). The first ring (shown as ring 1 in general formulas 100 and 200) is a six-membered aromatic carbocycle. The second ring (shown as ring 2 in general formulas 100 and 200) is an aromatic or non-aromatic 5- membered heterocycle that has at least two ring heteroatoms. Both the first and second rings may be substituted or unsubstituted.
The cyclometalating ligand is a bidentate ligand, and as such, two atoms form bonds with the Pt(II). The first metal-bonding atom is a carbon atom of the ring 1, and the second is an atom of the ring 2. In some embodiments, the atom of ring 2 is one of the at least two ring heteroatoms.
For clarity, schematics of an example cyclometalating ligand and a Pt complex, which is an intermediate product of Scheme 1, including the same cyclometalating ligand, are shown below.
. \ /
N
Cyclometalating ligand Newly formed ring =
\/
,N
Pt Tf0/ \SMe2 The working examples provide details regarding synthesis and characterization of compounds of general formula 200.
Acceptable substituents include any chemical moiety that does not interfere with the desired reaction or desired property such as luminescence, and may include, for example: R is a non-aromatic carbocycle or heterocycle, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, BR'2, BR'(ary1), B(aryl)2, aryl-B(aryl)2, 0, NR'2, OR, a nitrile group, C(halo)3which is optionally CF3, or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched or cyclic or any combination thereof;
A substituent may be further substituted.
In certain embodiments, boron disubstituted by respective substituted aryl carbocyclic moities (e.g., BMes2) is a substituent of the cyclometalating ligand either at the ring 1, at ring 2, or at both ring 1 and at ring 2. In some embodiments, this type of substituted cyclometalated ligand has phosphorescent properties. In certain embodiments, this type of substituted ligand is a blue phosphorescent compound. Also, when this type of substituted cyclometalating ligand is used to form a compound of general formula 100, a highly efficient phosphorescent Pt(II) compound can be achieved. In some embodiments, the phosphorescence is blue.
In some embodiments of general formula 100, the invention provides a compound wherein the boron moiety is substituted by two mesityl groups, see general formula 101 below.
R-(Mes)2B ii __________________________________________________ c 1 ______________________________________________ / X
Rrir \ -Pt7 /- - \
Y
'- - \ ----- RP
t The terms of general formula 101 are as defined for general formula 100. This embodiment is similar to general formula 100, except it specifies the substituents on boron.
The effect of the presence of such substituents (i.e., boron disubstituted by respective substituted aryl carbocyclic moities (e.g., BMes2)) on the N,C-chelate backbone plays several important roles in the high performance of the resulting Pt(II) compounds of general formula 100 in PhOLEDs. It facilitates the mixing of the 3LC and the MLCT state, thus enhancing the intrinsic phosphorescent efficiency of the molecule. It minimizes intermolecular interactions, thus enhancing emission efficiency in the solid state. Also, it facilitates electron injection into the emissive layer/dopant, thus improving the device efficiency. In certain embodiments of the invention, a compound of general formula 101 exhibits intense luminescence, which may be photoluminescence and/or electroluminescence.
Notably, compounds of general formula 101 comprise a phenyl ring (ring 1) that is bonded to the Pt. Ring 1 can be singly-substituted or multi-substituted. Ring 1 is substituted by a B(Mes)2 moiety in either the para or meta positions relative to Pt.
Optionally, it is also substituted by one or more R moieties. Suitable R substituents include any moiety that does not interfere with the luminescence of such compounds and may be fused rings (i.e, bound to ring 1 at two locations).
Importantly, when a B(Mes)2 moiety is bound to ring 1 at the para position relative to Pt, the compound's luminescence is blue in colour. When a B(Mes)2 moiety is bound to ring 1 at the meta position relative to Pt, the compound's luminescence is green, or greenish blue in colour. When a B(Mes)2 moiety is bound to ring 1 at the meta position relative to Pt, and ring 2 contains two fused aryl rings, then the compound's luminescence is yellow, orange or red in colour.
Compounds of general formula 101 further comprise a five-membered heteroaromatic ring (ring 2) that has at least two heteroatoms. Ring 2 can be singly-substituted or multi-substituted. Suitable R substituents include any moiety that does not interfere with the luminescence of such compounds. Optionally, ring 2 may be part of a fused ring system. The rings of the fused ring system may be substituted.
Another component of compounds described and characterized herein, is Pt(II).
In the synthesis of compounds of general formula 100, Pt(II) is obtained from a reactant that is a charge-neutral platinum(II) compound. In such reactants, a Pt(II) is bonded to four monodentate ligands. By being charge-neutral, this starting material is soluble in a variety of non-aqueous solvents (e.g., tetrahydrofuran (THF)). By having monodentate ligands occupying the four coordination sites of the Pt(II), this starting material is a good source of Pt(II) that is readily able to form bonds with a cyclometalating bidentate ligand. Thus, when treated with stoichiometric quantities of the cyclometalating ligand (e.g., 2-phenylpyridine ("ppy")) in an appropriate solvent at ambient temperature, the charge-neutral platinum(II) starting material reacts and affords a cyclometalated Pt(II) complex. Specifically, the first reaction product, Pt(ppy)Me(SMe2), is obtained through irreversible loss of a monodentate ligand (e.g., CH4).
An example of such a starting material for the synthesis of such cyclometalated Pt(II) diketonate or diketiminate complexes, is [PtMe2(SMe2)]2, which has been widely used as a precursor in C-H activation chemistry and can be easily prepared on a multi-gram scale from K2PtC14 (Scott, J. D.; Puddephatt, R. J. Organometallics 1983, 2, 1643-1648).
Other examples of suitable Pt starting materials include Pt(pheny1)2(DMS0)2 (Klein, A. et al., Organometallics, 2005,17, 4125) and [Pt(pheny1)2(SMe2)1, ( where n = 2,3) (Song, D.et al., J.
Organomet Chem.
2002, 648, 302-305).

Another starting material for the synthesis of such compounds of general formula 100 is a strong acid. Such an acid is able, for example, to protonate an alkanyl moiety (e.g., -CH3 is protonated to CH4). An example of a strong acid is HBF4. In some embodiments the strong acid is a strong organic acid. Examples of strong organic acids include: p-toluenesulfonic acid (Ts0H), trifluoroacetic acid (TEA), or picolinic acid (PA). For certain embodiments trifluoromethanesulfonic acid (Tf0H) may be used; however, for other embodiments this choice of acid may lead to unwanted side reactions.
In some cases, the acid not only protonates but also can act as the stabilizing ligand). As shown in the second step of Scheme 1, treatment of this reaction mixture with one equivalent of a solution of a strong organic acid (e.g., trifluoromethane sulfonic acid ("TfOH")) leads to rapid loss of a second equivalent of monodentate ligand (e.g., CH4) giving the corresponding complex (e.g., Pt(PPY)(OTO(SMe2)), which incorporates two labile ligands that can be replaced by a stabilizing ligand (see ring 3 of general formula 100). In some embodiments, the conjugate base of the strong acid acts as the stabilizing ligand (see compound 9, as an example where picolinate acts stabilizing ligand.) As shown in the third step of Scheme 1, another component of general formula 100 is known herein as a stabilizing ligand (see ring 3 of general formula 100). When introduced in the synthesis of compounds of general formula 100, this ligand is a negatively-charged bidentate chelate ligand, with a cationic counterion. This chelate has at least two heteroatoms (e.g., N, 0) wherein the at least two heteroatoms are each available for bonding to the Pt(II). The stabilizing ligand may be substituted or unsubstituted. The stabilizing ligand forms a 5-or 6-membered metallocycle with the Pt, which may be aromatic or non-aromatic, saturated or unsaturated, and may have fused rings bonded to the metallocycle. As shown in Scheme 1, exemplary stabilizing ligands include P-diketonato ("acac"), and p-diketiminato ("nacnac"). Other exemplary stabilizing ligands include picolinate, and N> HO
N .
The stabilizing ligand can be unsubstituted, singly-substituted, or multi-substituted. A
substituent may form fused rings with the metal-bonding heteroatoms (e.g.
pyridyl, triazole, pyrazole, imidazole, etc). Suitable substituents include any moiety that does not interfere with the phosphorescence of such compounds. Ring 3 may be part of a fused ring system. Such a fused ring system may be substituted.
A one-pot, two- or three-step reaction (number of steps depends whether the acid provides the stabilizing ligand) provides a product with general formula 100, which has P1(11) chelated by two different bidentate ligands wherein the first bidentate ligand is derived from the cyclonnetalating ligand and the second bidentate ligand is derived from the stabilizing ligand. As shown in the example reaction shown in Scheme 1, the reaction proceeds fairly quickly, at ambient temperature, and for this particular example, the product was isolated as analytically pure material in 87% yield following column chromatography.
1 [PtMe2(SMe2)]2 *
3 Na(acac) Pt N
THF/Me0H, 25 C, 3h one pot ,))c Scheme 1. One-pot synthesis of cyclometalated Pt(II) p-diketonates The working examples provide detailed descriptions of syntheses of specific compounds of general formulas 100 and 200, whose structures are shown in Table 1. As would be apparent to a person of ordinary skill in the art, other structural variations may be used according to the invention. Starting materials may be modified to include moieties that confer desirable physical or chemical properties, such as increased stability or luminescence.
Structural formulae of compounds of general formula 100 are shown in Table 1, together with data regarding their luminescence. Such compounds of general formula 100 are photoluminescent or electroluminescent. Thus, embodiments of the invention provide compounds that are photoluminescent and, in at least some embodiments of the invention, electroluminescent; they may produce intense light. In embodiments of the invention, a composition is provided which comprises a photoluminescent or electroluminescent compound of general formula 100, an organic polymer, and a solvent. In other embodiments of the invention, a composition is provided which comprises a photoluminescent or electroluminescent compound of general formula 200, an organic polymer, and a solvent.
The invention also provides a method of producing photoluminescence comprising the steps of: providing a photoluminescent compound of the invention having general formula 100 or general formula 200; and irradiating said photoluminescent compound with radiation of a wavelength suitable for exciting the compound to photoluminesce.

-The invention further provides a method of producing electroluminescence comprising the steps of: providing an electroluminescent compound of the invention having general formula 100 or general formula 200; and applying a voltage across said electroluminescent compound.
The invention further provides an electroluminescent device for use with an applied voltage, comprising: a first electrode, an emitter (e.g., phosphor) which is an electroluminescent compound of the invention optionally doped in a host material, and a second, transparent electrode, wherein a voltage is applied between the two electrodes to produce an electric field across the emitter.
The invention further provides an electroluminescent device for use with an applied voltage, comprising: a first electrode, an electron transport layer, an emitter (e.g., phosphor) which is an electroluminescent compound of the invention doped in a host material, a hole transport material, and a second, transparent electrode, wherein a voltage is applied between the two electrodes to produce an electric field across the emitter.
The emitter consequently electroluminesces. In some embodiments of the invention, the device includes one or more charge transport layers interposed between the emitter and one or both of the electrodes. For example, spacing of an embodiment of the device, called for the purposes of the present specification, a "three layer EL device", is: first electrode, first charge transport layer, emitter in a host layer, second charge transport layer, and second transparent electrode.
An advantage of certain embodiments of the invention is that they compounds that are soluble in common solvents such as toluene, diethyl ether, tetrahydrofuran (THF), and dichloromethane. This permits the compounds to be blended easily and conveniently with polymers. The role of the polymer in such a mixture is at least two-fold.
First, a polymer can provide protection for the compound from air degradation. Second, a polymer host matrix permits use of a solution-based process (e.g., ink-jet printing), a spin-coating process, or a dip-coating process as an alternative way to make films. Although spin-coating and dip-coating processes may not produce as high quality films as those produced by chemical vapor deposition (e.g., ink-jet printing) or vacuum deposition, they are often much faster and more economical.
Other embodiments of the invention provide compounds that are water-soluble.
Accordingly, the invention further provides methods of applying compounds as described above to a surface. These methods include solvent cast from solution, electrochemical deposition, vacuum vapor deposition, chemical vapor deposition, spin coating and dip coating.
The compounds may be applied alone or with a carrier. In some embodiments of the invention, they are applied in a composition including an organic polymer. Such compositions are also encompassed by the invention. As an example of this application, compounds of general formula 100 form a clear transparent solution with the weakly-luminescent polymer PMMA.
This can be converted to a transparent film by evaporating the toluene solvent via either a dip-coating or spin-coating process. Films obtained in this way are stable.
Certain polymers such as, for example, PVK, are expected to further enhance the luminescence of an emitter in the film. Conveniently, spin coating may be performed using a Chemat Technology spin-coater KW-4A; and vacuum deposition may be performed using a modified Edwards manual diffusion pump.
Certain compounds of the invention have high chemical and/or thermal stability. As a result, they are suitable for vacuum deposition methods used in fabricating single- or multi-layer OLED devices.
The invention provides a method of producing electroluminescence comprising the steps of: providing an electroluminescent compound of the invention having general formula 100 or general formula 200; and applying a voltage across said electroluminescent compound so that the compound electroluminesces.
According to the invention, electroluminescent devices for use with an applied voltage are provided. In general, such a device has a first electrode, an emitter which is an electroluminescent compound of the invention, and a second, transparent electrode, wherein a voltage is applied between the two electrodes to produce an electric field across the emitter of sufficient strength to cause the emitter to electroluminesce. Preferably, the first electrode is of a metal, such as, for example, aluminum, which reflects light emitted by the compound; whereas the second, transparent electrode permits passage of emitted light therethrough. The transparent electrode is preferably of indium tin oxide (ITO) glass, flexible polymer, or an equivalent known in the art. Here, the first electrode is the cathode and the second electrode is the anode.
Referring to Figure 1, an embodiment of an electroluminescent device of the invention is shown. In general, when a potential is applied across an OLED, holes are said to be injected from an anode into a hole transporting layer (HTL) while electrons are injected from a cathode into an electron transporting layer (ETL). The holes and electrons migrate to an ETUHTL
interface. Materials for these transporting layers are chosen so that holes are preferentially transported by the HTL, and electrons are preferentially transported by the ETL. At the ETL/HTL interface, the holes and electrons recombine to give excited molecules which radiatively relax, producing an EL emission that can range from blue to near-infrared (Koene, B.;
Loy, D.; and Thompson, M. Unsymmetrical Triaryldiamines as Thermally Stable Hole Transporting Layers for Organic Light-Emitting Devices. Chemistry of Materials. (1998) 10(8):
2235-2250).
As shown in Figure 1, the electron transport material is adjacent to the first electrode (the cathode, which can be, for example, LiF/Aluminum,). The emitter is doped in a host layer, which can be, for example, 4,4'-N,ff-dicarbazolebiphenyl (CBP) or tris(4-carbazoy1-9-ylphenyl)amine (TcTa). The hole transport material (for example, N,A1-61(1-naphthaleny1)-N,IT-dipheny1]-(1,1'-biphenyl)-4,4'-diamine (NPB),) is placed between the ITO electrode (the anode) and the emitting layer. The choice of the materials employed as charge transport layers and host layers will depend upon the specific properties of the particular emitter employed. The hole transport layer or the electron transport layer may also function as a host layer. The device is connected to a voltage source such that an electric field of sufficient strength is applied across the emitter. Light, preferably blue light, consequently emitted from the compound of the invention passes through the transparent electrode.
Referring to Figure 2A, absorption and emission spectra of BC1 and BC2 are shown.
Referring to Figures 2B and 2C, single crystals of both BC1 and BC2 were successfully obtained and were examined by X-ray diffraction analyses. The resultant crystal structures of BC1 and BC2 are shown (see Figures 2B and 2C, respectively). Both molecules display highly planar geometries about the Pt(II) centre with minimal strain apparent in either structure, important for the maximization of phosphorescent quantum yields. Strength of the carbene donor (carbene is ring 2 of general formula 100 for BC1 and BC2) is evident in both cases, exhibiting C
¨ Pt bond lengths shorter than those observed between the Pt(II) centre and the phenyl ring (ring 1 of general formula 100). The considerable trans influence of the carbene can also be observed, with the Pt-0 bond trans to the carbene lengthened by as much as 0.05 A relative to more common nitrogen donors in similar NAC chelate cyclometalated systems (see Hudson, Z.
M.; etal. Adv. Fund. Mater. 2010, 20, 3426). The crystal structures of both BC1 and BC2 show discrete dimeric Pt-Pt stacking, with Pt ¨ Pt distances of 3.389(2) and 3.505(2) A, respectively (for more detailed information see Supporting Materials of Hudson, Z.M.; et al. J.
Am. Chem. Soc.
(2012) 134: 13930-13933).
In Figure 2D, current efficiencies for OLEDs based on BC1 and BC2 are graphically displayed. In Figure 2E, power efficiencies for OLEDs based on BC1 and BC2 are shown. As _ shown, compounds of the invention display excellence current and power efficiencies. In Figure 2F, cyclic voltammetry diagrams of BC1 and BC2 are shown, which provide insight into the HOMO and LUMO levels.
Referring to Figures 3A-3F, emission spectra are shown for compounds Cl, C2, C3, C4, C5, C6 at 5% and 10% in PMMA, C8, C9, C10, C11 at 5% in PMMA, C12 at 1%, 5%
and 10%
doping level in PMMA, and C27 at 5% and 10% in PMMA.
Referring to Figures 4A-4B, absorption and emission spectra of compound Pt-12 are shown, respectively.
Referring to Figure 5A, an electroluminescence spectrum is shown for compound doped at 5% in a TcTa (tris(4-carbazoy1-9-ylphenyl)amine) host layer.
Referring to Figure 5B, a plot is shown presenting external quantum efficiency (EQE) versus luminance from compound C6. The C.I.E. coordinate for compound C6 was found to be (0.178, 0.197).
In some embodiments of the invention, an EL device includes one or more charge transport layers interposed between the emitter and one or both of the electrodes. Such charge transport layer(s) are employed in prior art systems with inorganic salt emitters to reduce the voltage drop across the emitter. In a first example of such a device, layers are arranged in a sandwich in the following order: first electrode, charge transport layer, emitter and host, second charge transport layer, and second transparent electrode. In anembodiment of this type, a substrate of glass, quartz or the like is employed. A reflective metal layer (corresponding to the first electrode) is deposited on one side of the substrate, and an insulating charge transport layer is deposited on the other side. The emitter layer which is a compound of the invention is deposited on the charge transport layer, preferably by vacuum vapor deposition, though other methods may be equally effective. A transparent conducting electrode (e.g., ITO) is then deposited on the emitter layer. An effective voltage is applied to produce electroluminescence of the emitter.
In a second example of an EL device of the invention, a second charge transport layer is employed, and the sandwich layers are arranged in the following order: first electrode, first charge transport layer, emitter and host, second charge transport layer and second, transparent electrode.
Electroluminescent devices of the invention may include one or more of the emitting compounds described herein. In some embodiments of the invention, an electroluminescent device such as a flat panel display device may include not only a blue- or green-emitting phosphor as described herein, but may be a multiple-color display device including one or more other phosphors. The other phosphors may emit in other light ranges, e.g., red, green, and/or be "stacked" relative to each other. Convenient materials, structures and uses of electroluminescent display devices are described in Rack, P.D.; Naman, A.;
Holloway, P.H.; Sun, S.-S.; and Tuenge, R. T. Materials used in electroluminescent displays." MRS
Bulletin (1996) 21(3): 49-58.
For photoluminescence, the compounds absorb energy from ultraviolet radiation and emit visible light near the ultraviolet end of the visible spectrum, e.g., in the blue region. For electroluminescence, the absorbed energy is from an applied electric field.
The invention further provides methods employing compounds of the invention to harvest photons, and corresponding devices for such use. Spectroscopic studies have demonstrated that compounds of the invention have high efficiency to harvest photons and produce highly polarized electronic transitions. In general, when such compounds are excited by light, a charge separation occurs within the molecule; a first portion of the molecule has a negative charge and a second portion has a positive charge. Thus the first portion acts as an electron donor and the second portion as an electron acceptor. If recombination of the charge separation occurs, a photon is produced and luminescence is observed. In photovoltaic devices, recombination of the charge separation does not occur; instead the charges move toward an anode and a cathode to produce a potential difference, from which current can be produced.
Molecules with the ability to separate charges upon light initiation are useful for applications such as photocopiers, photovoltaic devices and photoreceptors.
Photoconductors provided by the present invention are expected to be useful in such applications, due to their stability and ability to be spread into thin films. Related methods are encompassed by the invention.
Organic semiconducting materials can be used in the manufacture of photovoltaic cells that harvest light by photo-induced charge separation. To realize an efficient photovoltaic device, a large interfacial area at which effective dissociation of excitons occurs must be created;
thus an electron donor material is mixed with an electron acceptor material.
(Here, an exciton is a mobile combination of an electron and a hole in an excited crystal, e.g., a semiconductor.) Luminescent compounds as semiconductors are advantageous due to their long lifetime, efficiency, low operating voltage and low cost.
Photocopiers use a light-initiated charge separation to attract positively-charged molecules of toner powder onto a drum that is negatively charged.
The molecular design of compounds of general formula 100 was intended to achieve high-energy blue phosphorescence with maximum quantum yield (Op). The CAC or NAC chelate backbone presents a strong ligand field to the Pt(II) centre, raising the energy of non-radiative d-d excited states and reducing thermal quenching. An acetylacetonate (acac) stabilizing ring (ring 3) provides good solubility as well as solution- and solid-state stability, while its rigid structure and high triplet energy level help to increase (I)p. The BMes2 group and related BAr2 groups on ring 1 serve to greatly enhance metal-to-ligand charge-transfer phosphorescence.
As show in Table 2, doped PMMA films (10 wt%) of BC1 and BC2 exhibit good quantum yields of 90 and 86%, respectively, compared to only 13% for an analogous control compound lacking the BMes2 group. The solid-state quantum yield of BC2 represents the highest observed for a blue phosphorescent Pt(II) complex. BC1 exhibits blue-green phosphorescence in the solid state and solution, with an emission maximum of 478 nm in CH2Cl2. This emission is blue-shifted by 20 nm in BC2, resulting in sky-blue emission from the complex at Amõ = 462 nm (see Figures 2A-2F and Tables 2 and 3).
As shown in Table 3, BMes2-functionalized triazole chelate Pt(II) compounds and BMes2-functionalized benzimidazolyl chelate Pt(II) compounds display bright phosphorescence with emission colors ranging from blue to yellow or orange.
As shown in Figure 5, preliminary electroluminescent property evaluation indicated that BMes2-functionalized triazole chelate Pt(II) compounds are very promising as phosphorescent emitters in OLEDs.
Certain embodiments of the invention provide compounds suitable for use in biological and/or medical imaging. For example, for use in cells (in vivo or in vitro) to use the compounds' luminescent properties for visualizing structures such as tumours or other anomaly.
As described herein, triarylboron-functionalized metal-carbene and triarylboron-functionalized metal-triazole complexes have been prepared and tested. It has been shown that the boron moiety greatly increases the phosphorescent quantum yield of such complexes.
WORKING EXAMPLES
All reactions were carried out under air unless otherwise noted. Reagents were purchased from Aldrich chemical company (Oakville, ON, Canada) and used without further purification.
Solvents were freshly distilled over appropriate drying reagents. Thin Layer Chromatography _ was carried out on Si02 (silica gel F254, Whatman). Flash chromatography was carried out on silica (silica gel 60, 70-230 mesh). 1H and 13C spectra were recorded on a Bruker Avance 300 spectrometer () operating at 300 and 75.3 MHz respectively. Deuterated solvents were purchased from Cambridge Isotopes (St. Leonard, QC, Canada) and used without further drying.
Excitation and emission spectra were recorded using a Photon Technologies International QuantaMaster Model 2 spectrometer (Anaheim, California, USA) UV-visible absorbance spectra were recorded using a Varian Cary 50 UV-visible absorbance spectrophotometer (Varian, Inc. of Agilent Technologies, Mississauga, ON, Canada). Solution quantum yields were calculated using optically dilute solutions (A = 0.1) relative to Ir(ppy)3(T. Sajoto, P. I.
Djurovich, A. B. Tamayo, J.
Oxgaard, W. A. Goddard, M. E. Thompson, J. Am. Chem. Soc. 2009, 131, 9813-9822). Data collection for the X-ray crystal structural determinations were performed on a Bruker SMART
CCD 1000 X-ray diffractometer with graphite-monochromated Mo Ka radiation (A =
0.71073 A) at 298K and the data were processed on a Pentium PC using the Bruker AXS Windows NT
SHELXTL software package (version 5.10). Elemental analyses were performed by the University of Montreal Elemental Analysis Laboratory (Montreal, Canada).
Melting points were determined on a Fisher-Johns melting point apparatus. Conveniently EL spectra may be obtained using Ocean Optics HR2000; and data involving current, voltage and luminosity may be obtained using a Keithley 238 high current source measure unit.
Example 1. Fabrication on EL Device Devices were fabricated in a Kurt J. Lesker LUMINOS cluster tool with a base pressure of --10-8 Torr without breaking vacuum. The ITO anode is commercially patterned and coated on glass substrates 50 x 50 mm2 with a sheet resistance less than 15 0./square.
Substrates were ultrasonically cleaned with a standard regiment of Alconox , acetone, and methanol followed by UV ozone treatment for 15 min. The active area for all devices was 2 mm2. The film thicknesses were monitored by a calibrated quartz crystal microbalance. Current-Voltage characteristics were measured using a HP4140B picoammeter in ambient air. Luminance measurements and EL spectra were taken using a Minolta LS-110 luminance meter and an Ocean Optics USB200 spectrometer with bare fiber, respectively. The external quantum efficiency of EL devices was calculated following standard procedure. Additional details regarding device fabrication and characterization measurements have been described elsewhere (Hudson, Z. of aL
J. Am. Chem.
Soc. (2012) 134, 13930-13933).
Devices were fabricated by vacuum vapor deposition on ITO-coated glass substrates.

Due to the wide bandgaps of these materials, care was taken to ensure that the HOMO and LUMO energy levels of both emitters were contained within the bandgap of the host material, to ensure efficient trapping of both holes and electrons. Furthermore, it was necessary to employ a host material with a sufficiently high triplet level to ensure that excitons within the device were confined to the dopant. Based on these considerations, preliminary devices were fabricated using 4,4'-N,1\f-dicarbazolylbiphenyl (CBP) as the hole-transport layer, 1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBI) as the electron-transport layer, and N,Nr-dicarbazoly1-3,5-benzene (mCP) as host. These devices had a structure of ITO/Mo03 (1 nm)/CBP (35 nm)/mCP (5 nm)/mCP:emitter (12%, 15 nm)ITPBI (65 nm)/LiF (1 nm)/Al.
Example 2. One-Pot Synthesis of Cyclometalated Pt(I1)13-Diketonates pt,N
0"0 [PtMe2(SMe2)]2 (0.5 equiv) Na(acac) THF (2 equiv) Me0H
cF3so3H (1 equiv) õN ,N
Pt THF Pt Me/ NSMe2 Tf0 SMe2 General Synthesis To a 20 mL screw-cap vial equipped with a magnetic stir bar was added one equivalent of a cyclometalating ligand (0.35 mmol), [PtMe2(SMe2)]2 dimer (100 mg, 0.17 mmol), and 3 mL of THF. The resulting mixture was allowed to stir 1 hr at ambient temperature, then a solution of CF3S03H organic acid (1 mL, 0.35 M in THF) was added dropwise. The mixture was stirred for 30 minutes, then a solution of Na(acac) (0.70 mmol in 2 mL Me0H) was added. The mixture was stirred for 1.5 hours, then partitioned between water and CH2Cl2. The hydrophobic layer was washed with brine, dried over MgSO4, filtered, and concentrated under reduced pressure. The resulting residue was then purified using a plug of silica gel, with hexanes and CH2Cl2 as eluent, to give analytically pure material.

Characterization Data for Compounds Prepared Using the above general synthesis with the appropriate cyclometalating ligand (structural formulae shown in Table 1).
1 [ptme2(sme2)]2 2 TfOH
3 Na(R0(0)CHC(0)R N'Pt THF/Me0H, rt 0-0 la: 1H NMR (400 MHz, Chloroform-d) 59.00 (d, sat, Jpt_H = 41.8 Hz, J = 5.8 Hz, 1H), 7.80 (t, J =
7.8 Hz, 1H), 7.71 -7.55 (m, 2H), 7.45 (d, J = 7.6 Hz, 1H), 7.21 (t, J = 7.4 Hz, 1H), 7.15 - 7.06 (m, 2H), 5.48 (s, 1H), 2.01 (s, 6H) ppm, Anal. calc'd for C16H15NO2Pt: C 42.86, H
3.37, N 3.12; found C 43.56, H 3.39, N 2.98.
lb: 1H NMR (400 MHz, Chloroform-d) 6 9.00 (d, sat, Jpt_H = 40.9 Hz, J = 5.8 Hz, 1H), 7.81 (t, J =
7.7 Hz, 1H), 7.67 (d, J = 7.6 Hz, 1H), 7.63 (d, J = 8.1 Hz, 1H), 7.45 (d, J =
7.6 Hz, 1H), 7.22 (t, J =
7.4 Hz, 1H), 7.16 - 7.07 (m, 2H), 5.82 (s, 1H), 1.29 (s, 9H), 1.28 (s, 9H) ppm, Anal. calc'd for C22H27NO2Pt: C 49.62, H 5.11, N 2.63; found C 49.86, H 5.05, N 2.59.
1c: 1H NMR (400 MHz, Chloroform-d) 6 9.15(d, sat, Jpt-H = 39.0 Hz, J = 5.8 Hz, 1H), 8.11 (d, J =
7.3 Hz, 2H) 8.08 (d, J = 7.1 Hz, 2H), 8.01 (d, J = 7.1 Hz, 1H), 7.85 (t, J =
7.7 Hz, 1H), 7.80 (d, J =
7.3 Hz, 1H), 7.69 (d, J = 8A Hz, 1H), 7.57 (t, J = 7.3 Hz, 2H), 7.51 (t, J =
7.8 Hz, 4H), 7.29 (t, J =
8.3 Hz, 1H), 7.20 (t, J = 6.1 Hz, 1H), 7.15 (t, J = 7.5 Hz, 1H), 6.79 (s, 1H) ppm, Anal. calc'd for C26H19NO2Pt: C 54.54, H 3.35, N 2.45, found C 55.05, H 2.92, N 2.40.
2a: 1H NMR (400 MHz, Chloroform-d) 68.97 (d, sat, Jpt-H = 42.3 Hz, J = 5.8 Hz, 1H), 7.77 (t, J =
7.7 Hz, 1H), 7.57 (d, J = 8.0 Hz, 1H), 7.42 (s, 1H), 7.34 (d, J = 7.8 Hz, 1H), 7.07 (dd, J = 7.4, 5.8 Hz, 1H), 6.92 (d, J = 7.8 Hz, 1H), 5.48 (s, 1H), 2.41 (s, 3H), 2.03 (s, 3H), 2.01 (s, 3H) ppm; Anal.
calc'd for C17H17NO2Pt: C 44.16, H 3.71, N 3.03; found C 44.99, H 3.61, N
2.98.
2b: 1H NMR (400 MHz, Chloroform-d) 69.00 (d, sat, Jpt-H = 40.5 Hz, J = 5.8 Hz, 1H), 7.82 (t, J =
7.8 Hz, 1H), 7.64 - 7.47 (m, 2H), 7.36 (d, J = 8.3 Hz, 1H), 7.14 (t, J = 6.6 Hz, 1H), 7.10 (dd, J = 8.2, 2.1 Hz, 1H) 5.50 (s, 1H), 2.04 (s, 3H), 2.02 (s, 3H) ppm; 13C NMR (100 MHz, Chloroform-d) 6 185.8, 184.4, 167.3, 147.3, 143.1, 141.0, 138.3, 134.8, 130.0, 124.0, 123.6, 121.4, 118.5, 102.6, 28.2,27.1 ppm; Anal. calc'd for C16H14CIN02Pt: C 39.80, H 2.92, N 2.90; found C 40.29, H 2.91, N
2.68; m.p. > 300 C.

2c:1H NMR (400 MHz, Chloroform-d) 6 8.99 (d, sat, Jpt-H = 39.6 Hz, J = 5.8 Hz, 1H), 7.82 (t, J = 7.8 Hz, 1H), 7.72 (d, J = 1.8 Hz, 1H), 7.58 (d, J = 8.1 Hz, 1H), 7.32-7.23 (m, 2H), 7.15 (t, J = 6.5 Hz, 1H), 5.49 (s, 1H), 2.04 (s, 3H), 2.02 (s, 3H) ppm; 13C NMR (100 MHz, Chloroform-d) 6 185.8, 184.3, 167.3, 147.3, 143.5, 141.4, 138.3, 132.8, 126.5, 124.2, 123.9, 121.5, 118.5, 102.6, 28.2, 27.1 ppm, Anal. calc'd for C161-114BrNO2Pt: C 36.45, H 2.68, N 2.66; found C
36.89, H 2.63, N 2.56;
m.p. > 300 C.
3: 1H NMR (400 MHz, Chloroform-d) 6 9.07 (d, sat, Jpt-H = 40.7 Hz, J = 5.8 Hz, 1H), 8.04 (d, J = 8.1 Hz, 1H), 7.88(t, J= 8.1 Hz, 1E1), 7.32 (dd, J = 8.4, 4.9 Hz, 1H), 7.24 ¨ 7.17 (m, 1H), 7.14 ¨ 7.04 (dt, J = 10.9, 8.3 Hz, 1H), 5.49 (s, 1H), 2.02 (s, 3H), 2.01 (s, 3H) ppm; Anal.
calc'd for C161-113NO2FPt:
C 39.68, H 2.71, N 2.89; found C 40.11, H 2.70, N 2.78.
4: 1H NMR (400 MHz, Chloroform-d) 69.00 (d, sat, Jpt-H = 39.8 Hz, J = 5.8 Hz, 1H), 7.80 (t, J = 7.8 Hz, 1H), 7.58 (d, J = 8.1 Hz, 1H), 7.51 (d, J = 8.4 Hz, 1H), 7.10 (dd, J =
7.3, 5.6 Hz, 1H), 7.04 (d, J = 2.7 Hz, 1H), 6.91 (dd, J = 8.3, 2.7 Hz, 1H), 5.47 (s, 1H), 3.85 (s, 3H), 2.00 (s, 6H) ppm; 13C
NMR (100 MHz, Chloroform-d) 6 185.6, 183.9, 168.0, 157.1, 147.3, 145.0, 138.1, 131.1, 128.9, 121.3,118.3, 115.6,108.8, 102.5, 55.4, 28.3, 27.1 ppm, Anal. calc'd for C17H17NO3Pt: C 42.68, H
3.58, N 2.93; found C 43.19, H 3.55, N 2.79; m.p. 227-228 C.
5: 1H NMR (400 MHz, Chloroform-d) 58.41 (d, J = 6.9 Hz, 1H), 7.58 (d, J = 7.3 Hz, 1H), 7.37 (d, J
= 7.6 Hz, 1H), 7.15 (t, J = 7.4 Hz, 1H), 7.05 (t, J = 7.4 Hz, 1H), 6.74 (d, J
= 3.0 Hz, 1H), 6.34 (dd, J = 7.0, 3.0 Hz, 1H), 5.43 (s, 1H), 3.11 (s, 6H), 1.97 (s, 3H), 1.96 (s, 3H) ppm; 13C NMR (100 MHz, Chloroform-d) 6 185.1, 183.8, 166.7, 155.1, 146.0, 145.8, 138.1, 130.5, 128.3, 123.0, 121.9, 103.8, 102.3, 100.2, 39.4, 28.2, 27.2 ppm; Anal. calc'd for C18H20N202Pt: C
43.99, H 4.10, N 5.70;
found C 44.99, H 4.15, N 5.68; m.p. 265-266 C.

6: 1H NMR (400 MHz, Chloroform-d) 6 9.14 (d, J = 5.4 Hz, 1H), 8.26 (d, J = 8.0 Hz, 1H), 7.85 ¨

7.73 (m, 2H), 7.63 ¨ 7.57 (m, 2H), 7.53 (d, J = 8.8 Hz, 1H), 7.44 (dd, J =

8.0, 5.4 Hz, 1H), 5.54 (s, 1H), 2.07 (s, 6H) ppm; Anal. calc'd for C18H15NO2Pt: C 45.76, H 3.20, N 2.97;
found C 46.11, H
3.12, N 2.92.
7: 1H NMR (400 MHz, Chloroform-d) 69.57 (d, J = 8.9 Hz, 1H), 8.26 (d, J = 8.7 Hz, 1H), 7.85 ¨

7.72 (m, 4H), 7.59 (d, J = 7.7 Hz, 1H), 7.55 (dd, J = 8.1, 6.9 Hz, 1H), 7.23 (d, J = 7.5 Hz, 1H), 7.17 (t, J = 7.5 Hz, 1H), 5.58 (s, 1H), 2.06 (s, 3H), 2.05 (s, 3H) ppm; Anal.
calc'd for C201-117NO2Pt: C
48.19, H 3.44, N 2.81; found C 48.47, H 3.28, N 2.67.
8a: 1H NMR (400 MHz, Chloroform-d) 6 9.04 (s, sat, Jpt_H = 38.4 Hz, 1H), 7.88 (d, J = 8.0 Hz, 1H), 7.63 (d, J = 7.6 Hz, 1H), 7.57 (d, J = 8.1 Hz, 1H), 7.50 (d, J = 7.8 Hz, 1H), 7.22 (t, J = 7.4 Hz, 1H), 7.10 (t J = 7.5 Hz, 1H), 6.87 (s, 4H), 5.40 (s, 1H), 2.32 (s, 6H), 2.09 (s, 12H), 1.98 (s, 3H), 1.66 (s, 3H) ppm; Anal. calc'd. for C34H3613NO2Pt: C 58.63, H 5.21, N 2.01; found C
57.63, H 5.23, N 1.83.
8b: 1H NMR (400 MHz, Chloroform-d) 6 8.89 (d, sat, Jpt-H = 39.6 Hz, J = 5.3 Hz, 1H), 7.72 (t, J =
7.6 Hz, 1H), 7.47 (d, J = 7.8 Hz, 1H), 7.32-7.24 (m, 6H), 7.24-7.18 (m, 4H), 7.04 (t, J = 7.2 Hz, 2H), 7.00 (d, J = 6.5 Hz, 1H), 6.69 (dd, J = 8.4, 2.4 Hz, 1H), 5.39 (s, 1H), 1.97 (s, 3H), 1.73 (s, 3H) ppm, Anal. calc'd for C28H24N202Pt: C 54.63, H 3.93, N 4.55; found C 55.31, H 3.94, N 4.35.
8c: 1H NMR (400 MHz, Chloroform-d) 68.90 (s, sat, Jpt_H = 35.3 Hz, 1H), 8.01 (d, J = 8.5 Hz, 1H), 7.88 (d, J = 8.2 Hz, 1H), 7.79 (d, J = 8.2 Hz, 1H), 7.75 (d, J = 8.1 Hz, 1H), 7.52 ¨ 7.40 (m, 3H), 7.40 ¨ 7.31 (m, 2H), 7.23 (m, 6H), 6.99 (m, 1H), 6.85 (m, 5H), 6.55 (d, J = 8.5 Hz, 1H), 5.31 (s, 1H) 2.30 (s, 6H), 2.08 (s, 12H), 1.62 (s, 6H) ppm; Anal. calc'd for C50H47BN202Pt: C
65.72, H 5.18, N 3.07;
found C 66.09, H 5.07, N 3.08.
9a: 1H NMR (400 MHz, Chloroform-d) 6 8.86 (d, sat, Jpt_H = 42.8 Hz, J = 5.6 Hz, 1H), 8.08 (d, J =
7.8 Hz, 1H), 7.73 (t, J = 7.8 Hz, 1H), 7.44 (d, J = 8.3 Hz, 1H), 7.37-7.30 (m, 2H), 7.24 (t, J = 7.3 Hz, 1H), 7.03 (dd, J = 7.4, 5.8 Hz, 1H), 5.54 (s, 1H), 2.06 (s, 3H), 2.03 (s, 3H) ppm 13C NMR (100 MHz, Chloroform-d) 6 185.1, 183.6, 159.5, 156.6, 147.8, 138.9, 133.3, 125.4, 123.7, 122.8, 119.1, 116.6, 116.3, 111.1, 102.5, 28.1, 26.4 ppm; Anal. calc'd for C18H15NO3Pt: C
44.27, H 3.10, N 2.87;
found C 44.68, H 2.72, N 2.73; m.p. 247-248 C.
9b: 1H NMR (400 MHz, Chloroform-d) 6 8.92 (d, sat, Jpt-H = 40.0 Hz, J = 5.8 Hz, 1H), 8.83 ¨8.76 (m, 1H), 7.86 ¨ 7.78 (m, 1H), 7.72 (t, J = 7.8 Hz, 1H), 7.40 ¨ 7.28 (m, 4H), 6.96 (dd, J = 7.3, 5.8 Hz, 1H), 5.56 (s, 1H), 2.10 (s, 3H), 2.03 (s, 3H) ppm; Anal. calc'd. for C18F115NO2PtS: C 42.97, H 3.00, N 2.78; found C 42.97, H 2.71, N 2.76.
9c: 1H NMR (400 MHz, Chloroform-d) 6 8.92 (d, sat, Jpt_H = 40.7 Hz, J = 5.8 Hz, 1H), 8.30 (d, J =
7.9 Hz, 1H), 7.57 (t, J = 7.3 Hz, 2H), 7.49 (t, J = 7.3 Hz, 1H), 7.43 (d, J =
7.3 Hz, 2H), 7.36 (t, J =

. 7.9 Hz, 1H), 7.19(t, J = 7.5 Hz, 1H), 7.11 (t, J = 7.3 Hz, 1H), 7.02(d, J = 8.3 Hz, 1H), 6.79 (dd, J
= 7.3, 5.7 Hz, 1H), 6.38 (d, J = 8.2 Hz, 1H), 5.54 (s, 1H), 2.09 (s, 3H), 2.02 (s, 3H) ppm; 13C NMR
(100 MHz, Chloroform-d) 6 184.9, 183.5, 159.7, 148.2, 142.6, 142.3, 138.6, 138.1, 132.7, 129.6, 128.2, 127.9, 124.2, 123.6, 120.3, 118.2, 117.2, 116.5, 110.0, 102.4, 28.3, 26.4 ppm, Anal. calc'd for C24H20N202Pt: C 51.15, H 3.58, N 4.97; found C 51.67, H 3.51, N 4.73; m.p.
> 300 C.
Pt-Bppy (21): Yield: 92%. 1H NMR (400 MHz, CD2Cl2, 25 C, TMS) 6 = 9.24 (d, sat, 3J = 5.6 Hz, JPt-H = 36 Hz, 1H), 7.81 (td, 3J = 8.0, 4J= 1.6 Hz, 1H), 7.65-7.53 (m, 3H), 7.28 (dd, 3J = 7.6, 4J = 1.2 Hz, 1H), 7.18 (td, 3J= 6.4, 4J = 1.2 Hz, 1H), 6.87(s, 4H), 5.55 (s, 1H), 2.35 (s, 6H), 2.07 (s, 12H), 2.06 (s, 3H), 2.02 (s, 3H); 13C NMR (100 MHz, CD2Cl2, 25 C, TMS) 6=186.2, 184.4, 167.9, 147.9, 147.2, 144.9, 140.7, 138.2, 131.2, 130.3, 128.2, 128.1, 121.5, 118.6, 102.3, 27.9, 26.9, 23.2, 20.9. Anal. Calcd (%) for C33H35BNO2Pt: C, 57.99; H, 5.16; N, 2.05. Found: C, 57.89; H, 5.19; N, 2.08. This product was also obtained when Pt(pheny1)2(DMS0)2was used in place of [PtMe2(SMe2)]2=
Pt-Bmppy (22): Yield: 89%. 1H NMR (400 MHz, CD2Cl2, 25 C, TMS) 6 = 9.10 (dd, sat, 3J = 5.6 Hz, 4J = 1.2 Hz, Jpt-H = 42 Hz, 1H), 7.79-7.74 (m, 2H), 7.45 (d, sat, 3J = 7.7 Hz, Jpt-H = 28 Hz, 1H), 7.05 (td, 3J = 7.2 Hz, 4J =1.2 Hz, 1H), 6.84(d, 3J = 7.6 Hz, 1H), 6.70 (s, 4H), 5.41 (s, 1H), 2.40 (s, 3H), 2.20 (s, 6H), 1.93 (s, 12H), 1.87 (s, 3H), 1.45 (s, 3H); 13C NMR (100 MHz, CD2Cl2, 25 C, TMS) 6 = 186.3, 184.4, 168.4, 147.8, 146.2, 143.8, 143.4, 140.2, 138.5, 137.9, 134.8, 128.2, 128.0, 123.2, 120.8, 102.2, 28.0, 26.9, 22.8, 20.9. Anal. Calcd (%) for C34H376NO2Pt : C, 58.54; H, 5.35; N, 2.01. Found: C, 58.52; H, 5.38; N, 2.05. This product was also obtained when Pt(pheny1)2(DMS0)2was used in place of [PtMe2(SMe2)]2.
Pt-Bfppy (23): Bright yellow crystals were obtained after recrystallization from DCM/hexane. 1H
NMR (400 MHz, CD2Cl2, 25 C, TMS): 6= 9.11 (d, 4J = 0.5 Hz, 1H), 8.02 (d, 3J =
8.5 Hz, 1H), 7.86 (t, 3J = 8.0 Hz, 1H), 7.45 (d, 3J= 8.5 Hz, 1H), 7.20 (t, 3J = 7.5 Hz, 1H), 7.06 (t, 3J = 7.5 Hz, 1H), 6.85 (s, 4H), 5.54 (s, 1H), 2.33 (s, 6H), 2.10 (s, 12H), 1.75 (s, 3H), 1.15 (s, 3H). 13C NMR (100 MHz, CD2Cl2, 25 C, TMS): 6 = 186.4, 184.5, 147.4, 140.2, 138.8, 138.5, 137.6, 137.5, 128.1, 126.4, 123.4, 123.2, 121.6, 102.4, 27.9, 26.8, 22.8, 20.9. Anal. Calcd (%) for C34H35BFNO2Pt: C, 57.15;
H, 4.94; N, 1.96. Found: C, 56.97; H, 4.95; N, 1.87. This product was also obtained when Pt(pheny1)2(DMS0)2was used in place of [PtMe2(SMe2)12.

Example 3: Synthesis of boron-functionalized CAC-chelate carbene complexes BC1 and =I, II
Ek iii=

B
N
n-NH2 =
p: la, 90% p: lb, 85%
m: 2a, 83% m: 2b, 81%
O

iv i, ix-xi -vii viii igpir B ______________________________ ;=-N, Pt ¨ ____________________________________________ ¨
0 p p: lc, 38% p: Id, 80%
p: BC1, 25%
m: 2c, 73% m: 2d, 70% m: BC2, 17%
Scheme 2. Synthesis of boron-functionalized CAC-chelate carbene complexes.
Reagents and conditions: i) n-BuLi, THF, -78 C; ii) FBMes2, THF, -78 C to RT; iii) Pd/C, Ts0H, Et0H, 25 C; iv) glyoxal THF/Me0H, 25 C; v) H2CO, NH4CI, 25 C; vi) H3PO4, reflux; vii) Na0H(aq), 0 C; viii) Mel, THF, 25 C; ix) [PtMe2(SMe2)]2, -78 C to 55 C; x) Ts0H, 25 C; xi) Na(acac), THF/Me0H, -78 C.
N,N-dibenzy1-4-(dimesitylboryl)aniline (la): To a 250 mL Schlenk flask was added N,N-dibenzy1-4-bromoaniline (1.8 g, 5.1 mmol) and 80 mL dry THF. The resulting mixture was cooled to -78 C, then n-BuLi (3.5 mL, 5.6 mmol, 1.6 M in hexanes) was added dropwise with stirring. The reaction was stirred for 1 h at -78 C, and then FBMes2 (1.6 g, 6.1 mmol) was added.
The reaction mixture was stirred at -78 C for 1 h, then allowed to warm slowly to room temperature and stirred for 16 h. After removal of the solvent in vacuo, the mixture was washed with saturated aqueous NH4CI, then extracted with CH2Cl2 and water. The combined organic layers were dried using MgSO4, filtered, and purified using flash chromatography on silica gel (4:1 hexanes:CH2Cl2 as eluent) to afford 2.4 g la as a white solid (90% yield). 1H
NMR (400 MHz, sc _ CDCI3) (57.43 (d, J = 8.2 Hz, 2H, -C6H4-), 7.35(t, J = 7.1 Hz, 4H, -Ph), 7.32-7.22 (m, 6H, -Ph), 6.83 (s, 4H, Mes), 6.73 (d, J = 8.2 Hz, 2H, -C6H4-), 4.72 (s, 4H, -CH2-), 2.32 (s, 6H, Mes), 2.12 (s, 12H, Mes) ppm; 13C {1H} NMR (100 MHz, CDCI3) 5 152.5, 142.1, 140.6, 140.0, 137.8, 137.5, 133.0, 128.7, 127.9, 127.1, 126.7, 111.2, 53.8, 23.5, 21.1 ppm; HRMS (High Resolution Mass Spectrometry) calc'd for C38H40BN: 521.3254, found 321.3246.
4-dimesitylborylaniline (lb): To a 500 mL round-bottomed flask equipped with a magnetic stir bar was added la (2.37 g, 4.5 mmol), palladium on carbon (0.50 g, 5 wt% Pd), p-toluenesulfonic acid (0.50 g, 2.9 mmol) and ethanol (200 mL). The reaction was bubbled with hydrogen gas for 16 h at room temperature, then passed through a pad of celite and concentrated in vacuo. The residue was washed with 1M aq. NaOH, then extracted with CH2Cl2 and water. The combined organic layers were dried using MgSO4, filtered, and purified using flash chromatography on silica gel (1:1 hexanes:CH2Cl2 as eluent) to afford 1.31 g lb as a white solid (85%
yield). 1H NMR (300 MHz, CDCI3) (57.39 (d, J = 8.4 Hz, 2H, -C6H4-), 6.82 (s, 4H, Mes), 6.61 (d, J
= 8.4 Hz, 2H, -C61-14-), 4.03 (s, br, 2H, -NH2), 2.32 (s, 6H, Mes), 2.07 (s, 12H, Mes) ppm; 13C {1F1}
NMR (75 MHz, CDCI3) (5 150.5, 141.9, 140.7, 139.9, 137.7, 135.1, 128.0, 113.8, 23.4, 21.1 ppm;
HRMS calc'd for C24H28BN: 341.2315, found 341.2309.
N-(4-dimesitylborylphenyl)imidazote (lc): To a 100 mL round-bottomed flask with stir bar was added lb (1.12 g, 3.3 mmol), glyoxal (0.375 mL, 40 wt.%, 3.28 mmol) and 10 mL
1:1 THF:Me0H.
The reaction was stirred for 16 h at room temperature, then NH4CI (0.35 g, 6.6 mmol), formaldehyde (0.45 mL, 37 wt.%, 6.6 mmol) and 25 mL Me0H were added. The reaction was heated to reflux for 1 h, then 0.5 mL 85% H3PO4 was added. The mixture was heated to reflux for an additional 8h, then poured over ice (25 g), washed with 2M aq. NaOH, and extracted with CH2Cl2 and water. The combined organic layers were dried using MgSO4, filtered, and purified using flash chromatography on silica gel (4:1 ethyl acetate:hexanes as eluent) to afford 488 mg lc as a white solid (38% yield). 1H NMR (400 MHz, CDCI3) 67.94 (s, br, 1H, -Im), 7.63 (d, J = 8.2 Hz, 2H, -C6H.4-), 7.37 (d, J = 8.2 Hz, 2H, -C6H4-), 7.35 (s, br, 1H, -Im), 7.21 (s, br, 1H, -Im), 6.84 (s, 4H, Mes), 2.31 (s, 6H, Mes), 2.02 (s, 12H, Mes) ppm; 13C {1F1) NMR (100 MHz, CDCI3) (5144.8, 141.3, 140.7, 139.8, 139.0, 138.1, 135.4, 130.7, 128.3, 120.1, 117.7, 23.4, 21.2 ppm; HRMS
calc'd for C27H2913N2: 392.2424, found 392.2429.

t ,. N-(4-dimesitylborylphenyI)-N'-methylimidazolium iodide (1d): To a 25 mL
round-bottomed flask with stir bar was added 1c (400 mg, 1.01 mmol), methyl iodide (0.32 mL, 5.1 mmol) and 10 mL THF. After stirring at room temperature for 40 h under air, the white precipitate was filtered, washed with THE and dried to afford 433 mg Id (80% yield). 1H NMR (300 MHz, Me0H-d4) 6 9.59 (s, 1H, Im), 8.15 (d, J = 2.1 Hz, 1H, Im), 7.81 (d, J = 2.1 Hz, 1H, Im), 7.76 (d, J = 8.6 Hz, 2H, -C6H4-), 7.69 (d, J = 8.6 Hz, 2H, -C6H4-), 6.86 (s, 4H, Mes), 4.06 (s, 3H, -CH3), 2.30 (s, 6H, Mes), 1.99 (s, 12H, Mes) ppm; Anal. Calc'd for C28H33131N2: C 62.83, H 6.21, N 5.23, found C 62.82, H
5.99, N 5.12.
N,N-dibenzy1-3-(dimesitylborypaniline (2a): Prepared in analogy with la (83%
yield). 1H NMR
(400 MHz, CDCI3) 6 7.37 (t, J = 7.4 Hz, 1H, -C6H4-), 7.34-7.25 (m, 7H, -Ph, -C6H4-), 7.21-7.15 (m, 5H, -Ph, -C6H4-), 6.92 (s, 1H, -06H4-), 6.77 (s, 4H, Mes), 4.59 (s, 4H, -CH2-), 2.33 (s, 6H, Mes), 1.99 (s, 12H, Mes) 13C {1H} NMR (100 MHz, CDCI3) 6148.4, 146.4, 141.9, 140.6, 138.8, 138.0, 128.6, 128.5, 128.0, 126.9, 125.2, 121.0, 116.8, 112.5, 55.0, 23.2, 21.2 ppm;
HRMS calc'd for C38H40E3N: 521.3254, found 521.3260.
3-dimesitylborylaniline (2b): Prepared in analogy with lb (81% yield). 1H NMR
(400 MHz, CDCI3) 67.15 (t, J = 7.5 Hz, 1H, -C6H4-), 6.94 (d, J = 7.2 Hz, 1H, -C6H4-), 6.86-6.78 (m, 6H, -C6H4-, Mes), 3.52 (s, br, 2H, -NH2), 2.32 (s, 6H, Mes), 2.04 (s, 12H, Mes) ppm; 13C
{1H} NMR (100 MHz, CDCI3) 6 147.2, 145.9, 141.9, 140.8, 138.5, 128.8, 128.1, 126.8, 122.1, 118.7, 23.3, 21.2 ppm;
HRMS calc'd for C24H28BN: 341.2315, found 341.2319.
N-(3-dimesitylborylphenyl)imidazole (2c): Prepared in analogy with 1c (73%
yield). 1H NMR
(400 MHz, CDCI3) 67.76 (s, br, 1H, -Im), 7.52-7.42 (m, 4H, -C6H4-), 7.21 (s, br, 1H, -Im), 7.15 (s, br, 1H, -Inn), 6.83(s, 4H, Mes), 2.31 (s, 6H, Mes), 2.00 (s, 12H, Mes) ppm;
130 {1F1} NMR (75 MHz, CDCI3) 5 148.2, 141.1, 140.8, 139.3, 137.2, 135.6, 135.1, 130.1, 129.5, 128.4, 128.2, 124.6, 118.4, 23.4, 21.2 ppm; HRMS calc'd for C27F129BN2: 392.2424, found 392.2411.
N-(3-dimesitylborylphenyI)-N'-methylimidazolium iodide (2d): Prepared in analogy with 7.1 (70% yield). 1H NMR (400 MHz, Me0H-d4) 69.43 (s, 1H, Im), 7.98 (d, J = 2.1 Hz, 1H, Im), 7.87 (dt, J = 7.6 Hz, J = 1.7 Hz, 1H, -06H4-), 7.74 (d, J = 2.1 Hz, 1H, Im), 7.68 (t, J
= 7.7 Hz, 1H, -C6H4-), 7.66 (d, J = 1.7 Hz, 1H, -C6H4-), 7.65 (d, J = 7.9 Hz, 1H, -C6H4-), 6.86 (s, 4H, Mes), 4.00 (s, 3H, -CH3), 2.29 (s, 6H, Mes), 1.99 (s, 12H, Mes) ppm; 130 {1H} NMR (100 MHz, Me0H-d4) 6 150.5, =
. 142.4, 142.2, 141.2, 138.5, 137.2, 136.7, 131.7, 129.7, 129.6, 126.9, 125.9, 123.0, 37.1, 23.9, 21.5 ppm; Anal. Calc'd for C28H33BIN2: C 62.83, H 6.21, N 5.23, found C 62.92, H 6.53, N 4.58.
As shown in Scheme 2 above, compounds 1d and 2d were reacted using the general synthesis provided in Example 5 to form their Pt complexes BC1 and BC2 with the addition of cooling to the indicated temperatures. An analogous reaction with sodium nacnac in place of sodium acac would form Pt(B-NHC1)(nacnac) and Pt(B-NHC2)(nacnac).
Example 4. The following schematic shows a synthetic pathway for a organoboron ligand that comprises a BMes2functionalized phenyl ring and a triazole ring.
Scheme 3 Br Mes26µ
Mes26 Mes26 R i, ii iii, iv V /
---ill. ( ) _______________________________________________________________ l N
I
...............õ..,. --). ,.........õ7õ..7.
N-----N
Br Br .õCH2Ph Mes2B I/ / N

3a i) n-BuLi, -78 C, Et20, 1h; ii) BMes2F, RT, overnight; iii) TMS acetylene, Pd(PPh3).4, Cul, Et3N, 80 C, overnight; iv) NaOH, THF/Me0H, RT, 2h; v) RN3, Cu(CH3CN)4PF6, DIPEA, TBTA, DCM, RT.
Synthesis of (4-bromophenyl)dimesitylborane see steps (i) and (ii) of scheme 3: To a 100 mL Schlenk flask equipped with a magnetic stir bar was added para-dibromobenzene (1.0 g, 4.24mmol) and 30 mL of dry diethyl ether (Et20). The resulting solution was cooled to -78 C and stirred for 30 minutes. At that time, 2.9 mL of 1.6 M n-butyllithium (n-BuLi) (4.64mmol) was slowly added. The mixture was maintained at -78 C for 1h, and dimesitylboron fluoride (1.36g, 5.07mmol) was added. The resulting mixture was stirred at -78 C for another hour. It was then slowly warmed to room temperature (RT) and stirred overnight. The following morning, the _ solvent was removed under reduced pressure. A crude product was dissolved using dichloromethane solvent. The hydrophobic solvent solution was washed with brine and water.
The combined hydrophobic phase was dried over MgSO4 and filtered through filter paper. The product was further purified using flash chromatography through silica using hexane as eluent to afford 1.2 g of (4-bromophenyl)dimesitylborane, as a white solid (70% yield).
Notably, the above synthetic procedure could also be used to synthesize (3-bromophenyl)dimesitylborane when meta-dibromobenzene is used in place of para-dibromobenzene. Also, (2-bromophenyl)dimesitylborane can be synthesized when ortho-dibromobenzene is used in place of para-dibromobenzene.
Synthesis of (4-ethynylphenyl)dimesitylborane see steps (iii) and (iv) of scheme 3: A 100 mL three-necked round bottomed flask, equipped with a magnetic stir bar and condenser, was charged with ligand (4-bromophenyl)dimesitylborane (1.22 g, 3.03mmol), trimethylsilylacetylene (0.45mL, 3.44mmol), tetrakis(triphenylphosphine)palladium(0) (0.175g, 0.15mmol), copper iodide (0.03g, 0.15mmol) and 30 mL of degassed triethylamine. The mixture was stirred at 80 C for 20 hours, and then concentrated under reduced pressure. The product was dissolved in dichloromethane solvent. The hydrophobic solvent solution was then sequentially washed with saturated ammonium chloride solution, brine and water. The combined hydrophobic phase was dried over MgSO4 and filtered through a filter paper. The product was then purified using flash chromatography through silica using hexane as eluent. After removal of eluent solvent under reduced pressure, the resulting white solid was dissolved in 10 mL of tetrahydrofuran solvent and treated with sodium hydroxide in methanol (20 mL of a 2.0 M solution). After stirring for 2 hour, the resulting mixture was concentrated under reduced pressure. After extraction with dichloromethane, the hydrophobic solution was dried over MgSO4, filtered and the solvent was removed under reduced pressure to give the product (4-ethynylphenyl)dimesitylborane as a white solid (0.67g, 65%).
Notably, the above synthetic procedure could also be used to synthesize (2-ethynylphenyl)dimesitylborane or 3--ethynylphenyl)dimesitylborane when 2-and 3--bromophenyl)dimesitylborane are used instead of (4-bromophenyl)dimesitylborane, respectively.
Synthesis of 4-(4-(dimesitylboryl)pheny1)-1-benzyl-1,2,3-triazole (3a) see step (v) of scheme 3: To a 50 mL Schlenk flask equipped with a magnetic stir bar was added (4-ethynylphenyl)dimesitylborane (0.64g, 1.84mmol), benzyl azide (0.245g, 1.84mmol), diisopropylethylamine (0.475g, 3.68mmol), tris[(1-benzy1-1H-1,2,3-triazol-4-yl)methyl]amine (1 mol %) and 30 mL of dichloromethane. The resulting solution was bubbled with nitrogen gas for 20 minutes. [Cu(CH3CN)4]PF6 (1 mol %) was added as a catalyst. The resulting mixture was stirred overnight, after which the solvent was removed under reduced pressure.
The crude product was dissolved in dichloromethane. The solution was washed with saturated ammonium chloride solution, brine and water. Following isolation, the non-aqueous phase was dried over MgS0.4 and filtered through a filter paper. The product was then purified using flash chromatography through silica (4:1 hexanes:ethyl acetate as eluent) to afford 0.64 g 4-(4-(dimesitylboryl)pheny1)-1-benzy1-1,2,3-triazole (3a) as white solid (72%
yield).
Notably, the above synthetic procedure could also be used to synthesize 4-(3-(dimesitylboryl)phenyI)-1-benzyl-1H-1,2,3-triazole when (3-ethynylphenyl)dimesitylborane is used instead of (4-ethynylphenyl)dimesitylborane.
Example 5. Synthesis of Platinum complexes R Mes2 ( I.
v Mes2B Mes2B
Pt Pt / No /
N--N
R/
R/

30H2Ph H2Ph m/C
/C
Mes2B /
Mes2B
P/
/
Pt Pt N __________________________________________________________________ o) , Scheme 4 i) [PtMe2(u-SMe2)]2, acetone, 80 C, 2-3h; ii) p-toluenesulfonic acid, THF, 1h; iii) Na(acac), Me0H, overnight; iv) picolinic acid, Me0H, overnight.
Synthesis of Pt(4-(4-BMes2-phenyl)-1-benzyl-1,2,3-triazoly1)(acac) (C5), see scheme 4:
BMes2-functionalized phenyl-triazole (3a) ligand (0.10 mmol) and [PtMe2(u-SMe2)]2 (0.032 g, 0.055 mmol) were added to a 20 mL screw-cap vial with of acetone (5 mL).
The resulting mixture was heated to and maintained at 75 C for 2 hours. Then, a 0.10 M
solution of Ts0H in THF (1 mL) was added. The resulting solution was stirred for 1 hour. Next, 0.1 M solution of Na(acetylacetonate) in methanol (2 mL) was added and the mixture was stirred overnight. The solvent was then removed under reduced pressure. The crude product was dissolved in dichloromethane and washed with with brine and water. The combined non-aqueous phase was dried over MgS0.4 and filtered through a filter paper. The product was purified through silica using dichloromethane as the eluent to to afford 0.0195g C5 as yellow solid (24% yield). 1H NMR
(400 MHz, CD2Cl2):67.51 (s, 1H), 7.47(s, 1H), 7.40-7.28(m, 5H), 7.11 (d, 3J=7.6Hz, 1H), 7.07(d, 3J=7.6Hz, 1H), 6.74 (s, 4H), 5.49 (s, 2H), 5.37 (s,1H), 2.20 (s, 6H), 1.97 (s, 12H), 1.88 (s, 3H), 1.60 (s, 3H) ppm; elemental analysis calcd (%) for C38H40BN302Pt: C 58.77, H
5.19, N 5.41, found: C 58.76, H 5.21, N 5.39.
Synthesis of Pt-(4-(4-BMes2-phenyl)-1-benzy1-1,2,3-triazoly1)(picolinate) (C10): Ligand 3a (0.05g, 0.10mmol) and [PtMe2(u-SMe2)]2 (0.032g, 0.055mmol) were added to a 20mL screw-cap vial with 5mL of acetone. The mixture was heated at 75 C for 2 hours before 2mL of 0.10 M
solution of picolinic acid in methanol was added. The resulting solution was stirred overnight. After the solvent was removed under reduced pressure, the product was extracted with dichloromethane, and then washed with brine and water. The combined organic phase was dried over MgSO4, filtered and purified on silica (2:1 dichloromethane:ethyl acetate as eluent) to afford 0.021g of C10 as yellow solid (26% yield). 1H NMR (500 MHz, CD2C12):69.52 (d, 3J=5.6Hz, 1H), 8.14 (m, 1H), 7.80 (s, 1H), 7.70 (m, 1H), 7.62 (s, 1H), 7.50-7.42 (m, 5H), 7.27 (d, 3J=7.5Hz, 1H), 7.16 (d, 3J=7.5Hz, 1H), 6.88 (s, 4H), 5.64 (s, 2H), 2.34 (s, 6H), 2.06 (s, 12H); elemental analysis calcd (%) for C39H37BN402Pt: C 58.58, H 4.68, N 7.01, found: C 59.83, H 5.18, N 6.44.

-Synthesis of C11 A BMes2-functionalized phenyl-triazole ligand (0.10mmol) and [PtMe2(u-SMe2)]2 (0.032g, 0.055mmol) were added to a 20mL screw-cap vial with acetone (5mL). The resulting mixture was heated to and maintained at 75oC for 2 hours. Then, 0.1M solution of the 1,5-dimethy1-1H-pyrazole-3-carboxylic acid in methanol (2mL) was added. The resulting solution was stirred overnight. A precipitated solid was collected on a filter paper and washed with methanol, hexane and acetone (3 x 5 mL each) and dried in air.
Synthesis of C12 A BMes2-functionalized phenyl-triazole (3a) ligand (0.10 mmol) and [PtMe2(u-SMe2)]2 (0.032 g, 0.055 mmol) were added to a 20 mL screw-cap vial with of acetone (5 mL).
The resulting mixture was heated to and maintained at 75 C for 2 hours. Then, a 0.10 M
solution of Ts0H in THE (1 mL) was added. The resulting solution was stirred for 1 hour. Next, 0.1 M solution of 2-(1H-1,2,4-triazol-3-yl)pyridine in methanol (2 mL) was added and the mixture was stirred overnight. The solvent was then removed under reduced pressure. The crude product was dissolved in methanol and purified on TLC plate using acetone as the eluent.
Synthesis of Pt(BMes2-triazolyI)(picolinate) See C6-C11 of Scheme 4: The BMes2-functionalized phenyl-triazole ligand (0.10mmol) and [PtMe2(u-SMe2)]2 (0.032g, 0.055mmol) were added to a 20mL screw-cap vial with acetone (5mL). The resulting mixture was heated to and maintained at 75 C for 2 hours.
Then, 0.1M
solution of the corresponding picolinic acid or substituted picolinic acid in methanol (2mL) was added. The resulting solution was stirred overnight. A precipitated solid was collected on a filter paper and washed with methanol, hexane and acetone (3 x 5 mL each) and dried in air.

Synthesis of 2-(3-bromo-phenyl)-benzimidazole (see first step of scheme 5) COOH
Br Br 1. KOt-Bu Br 1. n-BuLi PPA 2. CH3I N
2. BIVIes2F
1110 "= __________________________________________________ NH2 THF, r.t.
THF, -78 C
B
B 1. PtMe2ISMe2)2 2. Ts0H, Na(acac) N/
11/ = THF, r.t. Pt Pt-12 imidazole 1 Scheme 5 3-bromobenzoic acid (2.0g, 9.9 mmol) was added to the solution of 1,2-phenylenediamine (1.07 g, 9.9 mmol) in polyphsphoric acid (PPA) (40 mL) at 120 C. The resulting solution was heated to and maintained at 150 C and stirred for 3 hrs. Upon cooling of the solution, it was poured into water. A resulting precipitate was filtered off. 10% NaOH aqueous solution was added to the filtrate until the pH was 10. In this process, a large quantity of precipitate was produced, which was then filtrated off using a filter paper. This filtrate was extracted with diethyl ether 3 times. 2-(3-bromo-phenyl)-benzimidazole was obtained as a white solid after the solvent was removed under reduced pressure (yield, 55%). 1H NMR (ppm, 300 M in d6-DMS0):
13.03 (1H, s), 8.37 (1H, s), 8.18 (1H, d, J= 8.18 Hz), 7.70 (2H, m), 7.53 (2H, m), 7.25 (2H, m).
Synthesis of N-Me-2-(3-bromo-phenyl)-benzimidazole (see second step of scheme 5) K-Ot-Bu (0.23 g, 0.2 mmol) was added to a stirred solution of 2-(3-bromo-phenyl)benzimidazole (0.45 g, 0.2 mmol) in THF for 20 min. Excess methyl iodide was added to the solution, which was then stirred overnight. After filtering off the precipitate and removal of the solvent under reduced pressure, N-Me-2-(3-bromo-phenyl)benzimidazole was obtained quantitatively. 1H NMR (ppm, 300 M in CDCI3): 7.97 (1H, s), 7.84 (1H, m), 7.69 (1H, d, J = 7.5 Hz), 7.64 (1H, J = 8.1 Hz), 7.38 (4H, m), 3.87 (3H, m).
Synthesis of N-Me-2-(3-BMes2-phenyl)-benzimidazole (see imidazole 1 in scheme 5) n-BuLi (0.8 mL, 1.3 mmol) was added slowly to a solution of N-Me-2-(3-bromo-phenyl)-benzimidazole (0.29 g, 1.0 mmol) in THF (30 mL) at -78 C and the resulting solution was stirred for about 1 hour at -78 C. BMes2F (0.37 g, 1.4 mmol) was then added under a stream of nitrogen and the solution was stirred at the same temperature for about 2 hours and then stirred overnight at ambient temperature. The solvents were removed under reduced pressure. The residue was purified over silica gel by flash column chromatography using a CH2Cl2/hexanes (1:1) mixture give a white powder of N-Me-2-(3-BMes2-phenyl)-benzimidazole ("imidazole 1") (0.23 g, 50%). 1H NMR (400 MHz, CDCI3, ppm): 8.08 (1H, broad), 7.90 (1H, b), 7.76 (1H, s), 7.73 (1H, m), 7.62 (1H, m), 7.41 (3H, b), 6.85 (4H, s), 3.78 (3H, s), 2.33 (3H, s), 2.05 (12H, s).
Synthesis of Pt complexes Pt-12 as shown in scheme 5 Pt complexs Pt-12 were synthesized using procedures similar to that reported in the literature procedure (Z. M. Hudson etal., Org. Lett. 2012, 14, 1700-1703). 1 eq of ligand imidazole 1(1 mmol) and 1 equivalent PtMe2(SMe2)2 (1 mmol) were combined and stirred at RT in 3mL THF
for 2hrs. 1 equivalent of p-tolunenesulfonic acid was added to the solution and stirred for another 0.5 h, which was then followed by the addition of 2 equivalents of Na(acac) in 2 mL Me0H. The mixture was stirred for 2 hrs. The solvent was then removed under vacuum and the residue was purified using column chromatograph on silica (dichlormethane /hexane: 1/1 v), producing Pt-12 in good yield. 1H NMR (400 MHz, CD2Cl2, ppm): 8.84 (1H, m), 7.77 (2H, m), 7.39 (3H, m), 7.32 (1H, dd, J= 8.0 Hz, J = 1.2 Hz), 6.89(4H, s), 5.06(1H, s), 2.35 (6H, s), 2.12(12H, s), 2.11 (3H, s), 2.02 (3H, s). 13C NMR (125.6 MHz, CD2Cl2, ppm): 185.4, 183.6, 141.7, 140.6, 138.3, 138.1, 132.4, 130.6, 128.0, 124.0, 123.0, 116.4, 109.6, 101.9, 31.2, 27.6, 27.0, 23.3, 21Ø
Absorption and emission spectra are shown for Pt-12 in Figures 4A and 4B. The solution luminescence quantum efficiency of Pt-12 compared to that of Ir(ppy)3 is 0.5. Compounds 51 and 52 are synthesized in a similar way to the synthesis of Pt-12, by replacing Na(acac) with Na(nacnac) in the reaction.
Syntheses of Pt complexes with nacnac as a stabilizing ligand are procedurally the same as the corresponding acac complex, except that sodium nacnac would be used instead of sodium acac. A person with skill in the art of the invention would recognize that this ligand with another counterion would be equivalent (e.g., potassium nacnac).
Example 6. Synthesis of 10, a PAC chelate Pt(II)P-diketonate complex Scheme 6. Synthesis of PAC chelate Pt(II) p-diketonate complex.
1 [PtMe2(SMe2)12, 55 C
2 TfOH, rt 65%
0-Pt'0 3 -7Failaet, rt To a 20 mL screw-cap vial equipped with a magnetic stir bar was added 1-naphthyldiphenylphosphine (97 mg, 0.35 mmol), [PtMe2(SMe2)]2 dimer (100 mg, 0.17 mmol) and 3 mL degassed THF. The resulting reaction mixture was stirred for 4 hours at 55 C under an N2 atmosphere. Then, HOTf (1 mL, 0.35 M in THF) was added dropwise. The mixture was stirred for 30 minutes at room temperature. A solution of Na(acac)-1-120 (98 mg, 0.70 mmol in 2 mL
Me0H) was then added. The mixture was stirred for 1.5 hours. The reaction mixture was then partitioned between water and CH2Cl2. The hydrophobic layer was washed with brine, dried over MgSO4, filtered, and concentrated under reduced pressure. The residue was then purified using a plug of silica gel (hexanes and CH2Cl2 as eluent) to give 10 as a white solid in 65% yield.
10: 1H NMR (400 MHz, Chloroform-d) 6 8.24(d, sat, Jpt-H = 44.6 Hz, J = 7.1 Hz, 1H), 7.91-7.80 (m, 5H), 7.67 (dd, J = 10.5 Hz, 7.1 Hz, 1H), 7.58 (dd, J = 8.1, 1.8 Hz, 1H), 7.51-7.36 (m, 8H), 5.52 (s, 1H), 2.16 (s, 3H), 1.93 (s, 3H) ppm; 13C NMR (100 MHz, Chloroform-d) 6186.10, 184.8 (d, JP-C =
3.7 Hz), 151.3 (d, Jr-c = 30.4 Hz), 134.12 (d, Jp_c = 52.7 Hz), 133.81 (d, d, Jp_c = 16.8 Hz), 133.24 (d, d, Jp_c = 15.0 Hz), 132.93 (d, Jp_c= 11.7 Hz), 130.9(d, Jp_c = 62.9 Hz), 131.1 (d, Jp_c = 2.6 Hz), 130.7 (d, Jp-c = 32.2 Hz), 128.8 (d, Jp-c = 1.8 Hz), 128.5, 128.4, 126.5, 125.0 (d, Jp-c = 10.3 Hz), 122.7, 101.6, 28.2, 28.1 (d, Jp_c = 6.6 Hz) ppm; 31P NMR (169 MHz, Chloroform-d) 28.27(s, sat, JIDt-P = 4671 Hz) ppm; Anal. calc'd for C27C2302PPt: C 53.55, H 3.83, found C
53.59, H 3.70; m.p.
222-223 C.

Example 7. Synthesis of 11, a CAC chelate Pt(II) /3-diketonate complex Scheme 7. Synthesis of a CAC chelate Pt(II) 0-diketonate complex.
N'l1= [PtMe2(SMe2)12, 55 C =

N
NN 2 TfOH, rt -Pt Ag 3 Na(acac), 0 0 61%
THF/Me0H, -40 C

To a 20 mL screw-cap vial with stir bar was added 1-methyl-3-phenylimidazol-2-ylidine)silver chloride (100 mg, 0.35 mmol), [PtMe2(SMe2)]2 dimer (100 mg, 0.17 mmol) and 3 mL degassed THF. The reaction was stirred for 1 hour, and then was filtered to remove Agl. The resulting mixture was then heated to and maintained at 55 C for two hours, and then was cooled to room temperature. HOTs (1 mL, 0.35 M in THF) was then added dropwise, and the mixture was stirred for 30 minutes at room temperature.
After cooling the reaction to -40 C, a solution of Na(acac).1-120 (49 mg, 0.35 mmol in 1 mL
Me0H) was added dropwise. The mixture was stirred for 2 hours, and then was allowed to warm to room temperature. After partitioning between water and CH2Cl2, the hydrophobic layer was washed with brine, and the combined extracts were dried over MgSO4. The solution was filtered and concentrated under reduced pressure. The resulting residue was purified using a plug of silica gel, with CH2Cl2 as eluent, to give 11 as a yellow solid in 61% yield.
11: 1H NMR (400 MHz, Chloroform-d) 6 7.78 (dd, sat, Jpt-H = 52.1 Hz, J = 5.3, 2.0 Hz, 1H), 7.24 (d, J = 2.0 Hz, 1H), 7.01 (m, 2H), 6.93 (dd, J = 6.8, 2.0 Hz, 1H), 6.80 (d, J =
2.0 Hz, 1H), 5.49 (s, 1H), 4.07 (s, 3H), 2.05 (s, 3H), 1.96 (s, 3H) ppm; Anal. calc'd for C15H16N202Pt: C
39.91, H 3.57, N
6.21, found C 40.34, H 3.60, N 6.08.
All scientific and patent publications cited herein are hereby incorporated in their entirety by reference.
Although this invention is described in detail with reference to embodiments thereof, these embodiments are offered to illustrate but not to limit the invention. It is possible to make other embodiments that employ the principles of the invention and that fall within its spirit and scope as defined by the claims appended hereto.

Table 1. Structural Formulae Compound Compound =

B
Pt = N<
\\O N
Pt Pt-(B-NHC1)(acac), BC1d ;
Pt-(B-NHC2)(acac), BC2d B
-N\ * = N{
Pt Pt \.N/
/K) Pt(B-NHC1)(nacnac) Pt-(B-NHC2)(nacnac) * 401 la B
1 . 8 = / N

---N
N---B-triazole1 B-triazole2 * 0 *
B
pezN
zN-_----N
Pt / \
Pt(B-triazole2)(acac) Pt(B-triazole1)(acac), Cl C5 .
e 0 .

-- = / N
/ N---N
-_----N Pt"
/ \ /
PtVN N. N
Pt(B-triazole2)(nacnac) Pt(B-triazole1)(nacnac) . 10 0 . J B = / N
z/ /
N--:---N
Pt, Pt / NN
Pt(B-triazole1 )(t-bu-acac), C2 Pt(B-triazole2)(pic), C10 11 : = B .
/
---N
N----.
N---,----N
Pt7 Pt 0' NN
o> 0> <
Pt(B-triazole1 )(p-Me-pic), C6 Pt(B-triazole2)(p-Me-pic), C10A

. B
/ N
= B li _____ rs __/ 7 7,N----Pt Pt OZ N
0; ),\I
) 0 ¨
Pt(B-triazole2)(o-Me-pic), C1OB
Pt(B-triazole1 )(o-Me-pic), C7 SO lei 10 = B. /1 . B .0 /
N

PtZ

C/ N NN > N
0> ) 0 Pt(B-triazole1 )(pic), C8 Pt(B-triazole2)(Me2-pyrazole-carboxylate), %
._ 0 . S_ a B / N-----B =
. / Nil --- N Pt/N---)1X
VNI--OZNN--N/
0 Pt(B-Me-triazole2)(acac) Pt(B-triazole1)(Me2-pyrazole-carboxylate) C11 C5A

=5) /
. B >.
NN. /N
NI-----":N
B-Me-triazole1 B-triazole3 1.1 le 111 B. /X I
N---P/1 PtV
Pt(B-Me-triazole1)(acac), C4 Pt(B-triazole3)(acac), C3 ._ . B

=
B >.
. /j N 4I /j 7 "Pt N¨N/ NN Pt (N) 0/ \
Trans- <¨) Pt(B-triazole3)(pic), C9 *
. B
/ii Pt, N/ N¨

Cis-Pt(B-triazole1)(py-1,2,4-triazole), C12 =0 401 fit B

-/ . B
,Ni --- . / 7 ,.., N¨N/ \N zN=_=.!--N
411 1 tst) 0 Pt Cis and trans <
Pt(B-triazole1)(5-py-3-ph-1,2,4-triazole), C13 Pt(B-triazole3)(p-Me-pic), C27 0 5.

B . r, =1 N'"----"N
Pt B-triazole4 N-/ \ NJ
F3C ) N -Cis and trans Pt(B-triazole1)(5-py-3-CF3 1,2,4-triazole), C14 0 *
-,z,----N

. B

Pf-VN

4I / 7 /\
NN-----"
Pt N-N/ \ N Pt(B-triazole4)(acac), C28 ) C>N
Cis and trans Pt(B-triazole1)(5-py-3-Me-1 ,2,4-triazole), C15 SI
101 liP

/ Pt ,N ,,,N-:...--N
1 5' . B

N a N-N/ NN
Cis, trans Pt(B-triazole4)(5-py-3-Me 1,2,4-triazole), Cis and trans Pt(B-triazole1)(3,5-py- 1,2,4-triazole), C16 -I

0lit 1 \( /j =8 .
PtVN N
N-N/ NN ?) V K
Cis and trans Cis and trans Pt(B-triazole2)(2-py-pyrazole), C30 Pt(B-triazole1)(2-py-pyrazole), C17 5>' = / it ptõ,N
N-N/ NN Pt / \ NV NN

N) ) Cis and trans Cis and trans Pt(B-triazole3)(3-Me-5-py- 1,2,4-triazole), Pt(B-triazole1)(2-py-4-ph-pyrazole), C18 = B. \
11 \N 0 6-Me-benzimidazole1 (imidazole 1) Pt N-N/ NN
F3C ) A. <
Cis and trans Pt(B-triazole1)(2-py-4-CF3 -pyrazole), C19 -_ 0 I/ Bli \N
41I B lit \ N =
= / hi N-_----N Pt /
/

Pt N¨N/ \ N ) Pt(B-Me-benzimidazole1)(acac), C26 Cis and trans (Pt-12) Pt(B-triazole1)(2-py-4-Me -pyrazole), C20 101 . B

4 .
11 \N 40 N---::-Pt --./ Pt `,N---N¨N/ \
Q ) Pt(B-Me-benzimidazole1 )(nacnac), 51 Cis, trans Pt(B-triazole1)(2-py-1 ,2,3-triazole), C21 O *
B \

* pt N
/
. /N---Z
Pt' N/ XN Pt(B-Me-benzimidazole2)(nacnac), 52 ) < ) N ¨
Cis and trans Pt(B-triazole1)(2-py-imidazole), C22 *lei 1 * \
B
N
B
N--'" = N lei Pt N/ NN * Pt pt,N) ) V 0 cis and trans Pt(B-triazole1)(2-py-4-ph-imidazole), C23 Pt(B-Me-benzimidazole2)(acac), (Pt-12A) 10 4. : V
le 841/ /1 = \ /
N N
Pt Pt N/ Nhj 0/ \O
õC N) cis and trans Pt(B-triazole1)(2-py-4-CF3 -imidazole), C24 21b . le V
B
= B
= iii z,N = \ /
Pt N
N/ \N Pt ) 0 / \

N -)L) Cis and trans Pt(B-triazole1)(2-py-4-Me -imidazole), C25 22b F
Pt/
)0at Ck0o 23b 24c V
Pt, N

25' P., 411 P"
q P
N
N/
Pt Ag )1 bY.-L. Rao, Chem. Eur. J., 2012, 18, 11306-11316.
cSoo-Byung Ko etal., Organometaffics, 2013, 32(2), 599-608.
dZ. M. Hudson etal., J. Am. Chem. Soc., 2012, 134, 13930-13933.

Table 2. Photophysical Properties of BC1 and BC2 Absorption, A. Amõõ (nm) Tpa CDpc Eided HOMO
LUMO
E (104 CM-1 Mla Solutiona/Sol (us) Solutiona/Solid (V)d (eV)e (eV) f idb BC1 381 (0.38), 344 478 / 482 6.9 0.87 / 0.90 -2.50 -5.73 -2.64 (1.16), 316 (2.15) BC2 371 (0.76), 356 462 / 464 3.4 0.41 / 0.86 -2.49 -5.86 -2.65 (0.80), 324 (1.48) [a] Measured in degassed CH2Cl2 at 1x10-5 M, rbrDoped into PMMA at 10 wt%.
rcr Solution quantum efficiencies were measured in CH2Cl2 relative to Ir(PPY)3 = 0.97.17 Solid state quantum yields (QY) were measured using an integration sphere. All QYs are 10%.
Ed) In DMF relative to FeCpr.
Eel Measured by UV photoelectron spectroscopy. rfi Calculated from the HOMO
level and the optical energy gap.

Table 3. Photophysical properties of BMes2-phenyl-triazolyl/imidazolyl-Pt compounds -Compound AmAnm] (1) PL
Cl (10 wt% PMMA) 471 0.10 C2 (10 wt% PMMA) 453 0.11 C3 (10 wt% PMMA) 455 0.09 C4 (10 wt% PMMA) 453 0.06 C5 (10 wt% PMMA) 493 0.63 C6 (5 wt% PMMA) 456 0.34 C6 (10 wt% PMMA) 456/540(br) 0.24 C7 (10 wt% PMMA) - -C8 (10 wt% PMMA) 454/563(br) 0.18 C9 (10 wt% PMMA) 457/544(br) 0.20 C10 (10 wt% PMMA) 487 0.54 C11 (10 wt% PMMA) 456 0.17 C12 (5 wt% PMMA)) 456, 544 0.60 C26 (in CH2C12) 485 nm 0.50 C27 (5 wt% PMMA) 454 0.21 C27 (10 wt% PMMA) 455/550(br) 0.15 Table 4. Electroluminescent Device Data of BC1 and BC2 Device BC1 BC2 Von (V) 4.0 3.6 Luminance . (cd m-2) 4165 2098 Current efficiency, max. (cd A-1) 53.0 25.8 Power efficiency, max. (Im W-1) 41.6 22.5 External Quantum efficiency, max (%) 17.9 9.8 C.I.E.a (x, y) (0.34, 0.53) (0.27, 0.50) a The International Commission on Illumination (abbreviated CIE for its French name) is the international authority on light, illumination, color, and color spaces.

Claims (26)

1. A compound having general formula (100):
wherein B is sterically sheltered and is located on ring 1 either para or meta to the C-Pt bond;
R is a non-aromatic carbocycle or heterocycle that is attached as a fused ring or as a substituent, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, B(R')2, BR'(aryl), B(aryl)2, aryl-B(aryl)2, O, NR'2, OR', a nitrile group, C(halo)3 which is optionally CF3, or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched, cyclic, or any combination thereof;
k, p and h are independently 0 to 5 and m and j are independently 0 to 3, and k, h and m are not all 0, with the proviso that there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack on the B, and wherein if there is only one substituent that is ortho to B, then that substituent is branched C3, branched C4, or linear or branched C5-or higher;
t is 0 or 1;
a dotted line in a ring indicates that the ring can be saturated, unsaturated, aromatic, or non-aromatic;

X is independently C or N and at least two X are N; and Y is independently N or O;
wherein a substituent can be further substituted.

2. The compound of claim 1, comprising at least two C1 substituents which are both are located ortho to the boron.

3. A compound as claimed in claim 1 or 2, wherein the compound is photoluminescent or electroluminescent.

4. The compound of claim 1, which comprises a compound of general formula 101:
wherein R, m, j, p, t, X and Y are defined in claim 1, and Mes is mesityl.

5. The compound of claim 4, wherein Y is oxygen.

6. The compound of claim 4, wherein the at least two X that are N are three X that are N, so that ring 2 is a triazole.

7. The compound of claim 3, which is BC1 or BC2.

8. The compounds of claim 3, which is a Pt(II) complex shown in Table 1.

9. The compounds of claim 3, wherein the compound is C5, BC1-acac, BC1-nacnac, BC2-acac, or BC2-nacnac, Pt-12, 51, or 52.

10. A compound of general formula 200 wherein B is sterically sheltered and is located on ring 1 either para or meta to the C-Pt bond;
R is a non-aromatic carbocycle or heterocycle that is attached as a fused ring or as a substituent, an aryl group that is attached as a fused ring or as a substituent, aliphatic-aryl, hydroxy, nitro, amino, halo, B(R)2, BR'(aryl), B(aryl)2, aryl-B(aryl)2, O, NR'2, OR', a nitrile group, C(halo)3which is optionally CF3, or R', where R' is independently an aliphatic group having 1-24 carbon atoms which may be straight, branched, cyclic, or any combination thereof;
k and h are independently 0 to 5 and m and j are independently 0 to 3, and k, h and m are not all 0, with the proviso that there is at least one substituent located ortho to B so that the boron is sufficiently sterically sheltered to prevent nucleophilic attack on the B, and wherein if there is only one substituent that is ortho to B, then that substituent is branched C3, branched C4, or linear or branched C5-or higher;
t is 0 or 1;
a dotted line in a ring indicates that the ring can be saturated, unsaturated, aromatic, or non-aromatic;
X is independently C or N and at least two X are N; and Y is independently N or O.

11. The compound of claim 10, wherein the compound is photoluminescent or electroluminescent.

12. The compound of claim 10, which is B-NHC1, B-NHC2, B-triazole1, B-triazole2, B-Me-triazole1, B-triazole3, B-triazole4, or B-Me-benzimidazole1 .

13. A composition comprising a photoluminescent or electroluminescent compound as claimed in claim 3 or claim 11, an organic polymer, and a solvent.

14. A photoluminescent product or an electroluminescent product comprising a compound as claimed in claim 3 or claim 11.

15. The product of claim 14 which is a flat panel display device or a lighting device.

16. The product of claim 14 which is a luminescent probe or sensor.

17. A method of producing electroluminescence, comprising the steps of:
providing an electroluminescent compound as claimed in claim 3 or claim 11 and applying a voltage across said compound so that said compound electroluminesces.

18. An electroluminescent device for use with an applied voltage, comprising:
a first electrode, an emitter which is an electroluminescent compound as claimed in claim 3 or claim 11 optionally in a host layer, and a second, transparent electrode, wherein voltage is applied to the two electrodes to produce an electric field across the emitter so that the emitter electroluminesces.

19. An electroluminescent device for use with an applied voltage, comprising:
a first electrode, a second, transparent electrode, an electron transport layer adjacent the first electrode, a hole transport layer adjacent the second electrode, and an emitter which is an electroluminescent compound as claimed in claim 3 or claim 11 optionally in a host layer, interposed between the electron transport layer and the hole transport layer, wherein voltage is applied to the two electrodes to produce an electric field across the emitter so that the emitter electroluminesces.

20. A method of harvesting photons comprising the steps of: providing a compound as claimed in claim 1 or claim 10, and providing light such that photons strike said compound and charge separation occurs in said compound.

21. The method of claim 20, wherein said separated charges recombine and photons are released.

22. The method of claim 20, wherein said separated charges migrate to respective electrodes to produce a potential difference.

23 A method of separating charges comprising the steps of: providing a compound as claimed in claim 1 or claim 10, and providing light such that photons strike said compound and charge separation occurs in said compound.

24. The method of claim 23, wherein said separated charges recombine and photons are released.

25. The method of claim 23, wherein said separated charges migrate to respective electrodes to produce a potential difference.

26. A photocopier employing the method of claim 20 or 23.
28. A photovoltaic device employing the method of claim 20 or 23.
29. A photoreceptor employing the method of claim 20 or 23.
30. A solar cell employing the method of claim 20 or 23.
31. A semiconductor employing the method of claim 20 or 23.
32. A light emitting device comprising:
an anode;
a cathode; and an emissive layer, disposed between the anode and the cathode, wherein the emissive layer comprises a compound of general formula 100 of claim 1 or a compound of general formula 200 of claim 10.
33. The device of claim 32, wherein the emissive layer further comprises a host.
34. A consumer product comprising the device of claim 32.