WO2004106436A1

WO2004106436A1 - Phthalocyanine compounds

Info

Publication number: WO2004106436A1
Application number: PCT/CA2004/000808
Authority: WO
Inventors: Barry A. P. Lever; Clifford Leznoff
Original assignee: York University
Priority date: 2003-05-30
Filing date: 2004-05-31
Publication date: 2004-12-09

Abstract

Phthalocyanine compounds having the formula (II); wherein: M is Ni, Pb or Mn; and R is the same or different and is chosen from the group consisting of: neopentoxy; cyclohexylmethyloxy; substituted or non-substituted, cyclic or non-cyclic alkoxy; and substituted or non-substituted benzyloxy. A method for producing the present compounds is also provided.

Description

PHTHALOCYANINE COMPOUNDS

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION [0001] The present invention relates to novel phthalocyanine compounds, and phthalocyanine analogs, and a method of synthesizing such compounds. More specifically, the present invention provides, in one aspect, hexadeca substituted phthalocyanines, and analogs thereof, having a unique absorption spectra or signatures that result in the compounds exhibiting a red color. The invention also provides a method for preparing metallo phthalocyanines.

DESCRIPTION OF THE PRIOR ART [0002] Phthalocyanines are macrocycle molecules consisting of four isoindole units joined by aza nitrogens. Due to their intense blue-green color and their thermal and chemical stability, phthalocyanines have been used commercially as colorants in dyes (e.g. for use in optical recording media such as RW-CD ROM's), pigments, paints (e.g. for use on automobiles), plastics and color photography. In addition, phthalocyanines find many other uses such as: catalysts; photo-conducting elements in photocopiers; applications in molecular electronics, such as for semiconductors or display devices; and, in medicine as reagents for photodynamic therapy. Various other uses of phthalocyanines are known in the art as described by A.B.P. Lever in Chemtech, 17, pp. 506-510, 1987 (the contents of which are incorporated herein by reference) .

[0003] The general structure of phthalocyanines (usually abbreviated as Pc) is represented by formula I below:

[0004] (I)

[0005] Substituents at the 2,3,9,10,16,17,23, and 24 positions are typically referred to as peripheral groups, while substituents at positions 1,4,8,11,15,18,22, and 25 positions are typically referred to as non-peripheral groups.

[0006] The aza nitrogens in the meso positions of phthalocyanines give these compounds greater thermal stability and a lower susceptibility to oxidation when compared to porphyrms. The 18-7T electron systems that make up the core of both porphyrins and phthalocyanines are further delocahzed into the benzo-subunits of the phthalocyanine. This delocalization causes the highly red-shifted maximum absorption (λ_max) in the Q-band region (600 to 800 nm) of the UV-visible spectrum of phthalocyanines compared to that of porphyrins.

[0007] The phthalocyanine (Pc) compounds can optionally be provided with covalently bound metal atoms in the centre of the ring structure. Various metals are known to be used for this purpose including diamagnetic metals (Ni, Zn, Pb) and paramagnetic metals (Mn, Co). Examples of other metals are provided, for example, in US patent number 6,384,027, the contents of which are incorporated herein by reference. Certain derivatised phthalocyanine compounds exhibit liquid crystal phases, usually discotic columnar phases. The interaction between the rigid central aromatic regions of the phthalocyanine maintains columnar stacking of the molecules, while substituted side-chains provide columnar mobility. These liquid crystalline phases can be processed into ultra-thin ordered films, increasing the potential of these compounds for device applications.

[0008] It is known in the art that the choice of substituents for the Pc ring structure, and the metal atom provided therein, affect the physical characteristics of the molecule and, in turn, its absorption signature (i.e. its λ_max). For example, an unsubstituted Pc compound, without a metal atom, typically has a λ_max of 700 nm. The same for an unsubstituted Pc with a central metal atom is typically 670 nm (which gives the compound a blue/violet color). A Pc substituted with 16 Cl atoms (i.e. a hexadeca-substituted Pc wherein all peripheral and non-peripheral positions are substituted with Cl) and provided with a central Cu metal atom typically has a green color.

[0009] Various attempts have been made to vary the absorption signatures of Pc compounds by varying the substituents and/or the central metal atom. Although various absorption signatures have been achieved, it has proven difficult to achieve Pc compounds that have absoφtion signatures that allows the compounds to exhibit a red or orange colour. The few resulting compounds were often found to be unstable (for example, they rapidly deteriorate when exposed to an oxidizing environment such as when exposed to oxygen) and, therefore, not commercially viable. Furthermore, some of the metal atoms used for this puφose were toxic, thereby further reducing the commercial viability of such compounds.

[0010] US patent number 6,384,027 teaches phthalocyanine derivatives wherein a pyridinoid ring is incoφorated in or around the Pc nucleus and having absoφtion spectra in the red or near infra red region. This reference also teaches various applications of Pc compounds having such absoφtion characteristics, which are incoφorated herein by reference.

[0011] Thus, there exists a need for a stable and commercially viable phthalocyanine (Pc) compounds having absoφtion signatures in the red or nearly red wavelengths. There also exists a need for an improved method of producing metal-Pc compounds. SUMMARY OF THE INVENTION

[0012] In one aspect, the present invention provides a compound having the following formula II:

[0013] (II)

wherein: M is Pb or Mn; and R is the same or different and is chosen from the group consisting of: neopentoxy; cyclohexylmethyloxy; substituted or non-substituted, cyclic or non-cyclic alkoxy; and substituted or non-substituted benzyloxy.

[0014] In another aspect, the invention provides a method for producing a metal hexadeca substituted phthalocyanine comprising:

a) providing a tetra substituted phthalonitrile; b) reacting said tetra substituted phthalonitrile with phenyl magnesium bromide to produce a magnesium hexadeca substituted phthalocyanine; c) treating the magnesium hexadeca substituted phthalocyanine to release the magnesium from the ring structure to result in a metal-free hexadeca substituted phthalocyanine; d) treating the metal-free hexadeca substituted phthalocyanine with a metal acetate to result in a metal-hexadeca substituted phthalocyanine.

[0015] In one aspect, the present invention provides hexadeca substituted phthalocyanines that exhibit a maximum absorbance (λ_max) at a wavelength greater than 800 nm.

[0016] In another aspect, the present invention provides a manganese- 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadeca-substituted phthalocyanine.

[0017] In another aspect, the present invention provides a manganese- 1,2,3,4,8,9,10,11, 15,16,17,18,22,23,24,25-hexadecaneopentoxyphthalocyanine.

[0018] In another aspect, the present invention provides a manganese- 1 ,2,3 ,4,8,9, 10, 11 , 15 , 16, 17, 18,22,23 ,24,25-hexadeca(cyclohexylmethyloxy)phthalocyanine.

[0019] In another aspect, the invention provides a method of forming Pc compounds from the analogous metal-free phthalocyanines.

[0020] In another aspect, the invention provides a nickel- 1 ,2,3,4,8,9, 10,11,15,16,17,18,22,23,24,25-hexadeca(cyclohexylmethyloxy)phthalocyanine.

[0021] In another aspect, phthalocyanines of the present invention exhibit an absoφtion signature at a wavelength that is red-shifted so significantly that the compound appears red in color in its solid form. These phthalocyanine compounds are also characterized by forming a deep red solution when dissolved in organic solvents. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] These and other features of the invention will become more apparent in the following detailed description in which reference is made to the appended drawing wherein:

[0023] Figure 1 is schematic representation of a process used to produce the preferred phthalocyanines of the present invention.

[0024] Figure 2 is an absoφtion spectrum of magnesium- hexadecaneopentoxyphthalocyanine.

[0025] Figure 3 is an absoφtion spectrum of metal-free hexadecaneopentoxyphthalocyanine.

[0026] Figure 4 is an absoφtion spectrum of lead- hexadecaneopentoxyphthalocyanine.

[0027] Figure 5 is an absoφtion spectrum of manganese- hexadecaneopentoxyphthalocyanine.

[0028] Figure 6 is an absoφtion spectrum of nickel- hexadeca(cyclohexylmethyloxy)phthalocyanine.

[0029] Figure 7 is an absoφtion spectrum of magnesium- hexadeca(cyclohexylmethyloxy)phthalocyanine.

[0030] Figure 8 is an absoφtion spectrum of metal- free hexadeca(cyclohexylmethyloxy)phthalocyanine.

[0031] Figure 9 is an absoφtion spectrum of manganese hexadeca(cyclohexylmethyloxy)phthalocyanine.

DETAILED DESCRIPTION OF THE INVENTION

[0032] The present invention relates to a novel phthalocyanine compound and a method of synthesizing such compound. In previous research, the present inventors had found that neopentoxy groups can be used to cause a red-shift in the Q-band region of the UN- visible spectra of phthalocyanines (Lever, A.B.P., Adv. Inorg. Radiochem., 1965, 27,21; the contents of which are incoφorated herein by reference). In addition, these bulky peripheral groups were found to disrupt 7T-stacking between macrocycles and, therefore, increase the solubility of the substituted phthalocyanines.

[0033] The present inventors had previously noted that providing sixteen neopentoxy groups on the phthalocyanine (Pc) molecule greatly red-shifted the UN-visible absoφtion spectrum to the red (Bhardwaj, Ν.; Andraos, J.; Leznoff, C; The Syntheses and NMR studies of hexadeca- and octaneopentoxyphthalocyanines, C. C. Can. J. Chem., 2002, 80, 141; the contents of which are incoφorated herein by reference). With prior art methods, it was found to be difficult to prepare metal-free, highly hindered phthalocyanines since only nickel- hindered phthalocyanines could be prepared, even though many standard and other methods were tried. However, the present inventors have succeeded in making metal-free, highly hindered phthalocyanines using magnesium alkoxides as described further below. This then provided a method of inserting metals other than nickel into highly hindered phthalocyanines. Cobalt and lead hexadecaneopentoxyphthalocyanines were prepared with the lead PC showing an absoφtion in the visible-near IR region at exactly 800 nm and these compounds were green or greenish blue as usual. Later, for the puφoses of electrochemical studies, a manganese phthalocyanine was attempted. This resulted in the unusual red phthalocyanine of the present invention.

[0034] The substituents, such as the neopentoxy and cyclohexylmethyloxy substituents, of the Pc compounds of the invention serve two important functions not previously seen in known phthalocyanines. The substituents not only prevent aggregation of the molecules due to their "bulky" structure, causing shaφ peaks in the near IR spectrum, but also distort the phthalocyanine (Pc) ring so that these absoφtions are shifted into the near IR wavelength range. Equally important, for practical applications, substituents such as the neopentoxy groups have no β-hydrogens and, as such, elimination reactions are prevented. This enhances the air and heat stability of this compound. Other substituents, such as substituted benzyloxy groups or alkoxy groups, containing no hydrogens at positions beta to the oxygen would have similar properties. [0035] The phthalocyanines of the present invention have the following formula II:

[0036] (II)

wherein M is a metal atom having an oxidation state of +2 and, more preferably, is manganese (Mn) or lead (Pb). The R groups are the same or different and may be chosen from: neopentoxy; cyclohexylmethyloxy, substituted or non-substituted or cyclic alkoxy; and substituted or non-substituted benzyloxy. The alkoxy substituents preferably are C or greater and may be as large as C₅₀ or more.

[0037] Preferably, the R substituents are the same and have no hydrogens at positions beta to the oxygen. In one aspect, R represents neopentoxy. In another aspect, R represents cyclohexylmethyloxy.

[0038] The phthalocyanines of the invention are substituted at all peripheral and non- peripheral groups and are preferably metallated with manganese or lead. The manganese- phthalocyanines result in red colored compounds. The lead-phthalocyanines result in light green colored compounds. [0039] In addition to those listed above, specific examples of applications particularly of the red phthalocyanines of the invention include: use in optical limiting devices to block IR radiation; use in optical recording materials for direct-read-after-write devices; use as a photothermal converting agent; use as red pigment; use in heat ray shielding films; use as photosentiziers in photodynamic therapy in treating cancer; use in conductometric and optical based sensors; use in Langmuir-Blodgett films; etc.

[0040] Figure 1 depicts a preferred method for synthesizing one group of phthalocyanines of the present invention, namely the hexadecaneopentoxyphthalocyanines. Generally, the method first involves the production of a magnesium hexadecaneopentoxyphthalocyanine (10) by means of a Grignard reaction (12). The hexadecaneopentoxyphthalocyanine molecule comprises the neopentoxy R groups as shown at (13). The magnesium Pc compound is then treated (14) to release the metal from the ring structure, thereby resulting in a metal-free hexadecaneopentoxyphthalocyanine (16). This compound is then treated (18) with an acetate of the desired metal, i.e. manganese or lead, to result in the desired metal- hexadecaneopentoxyphthalocyanine (20).

[0041] The manganese phthalocyanines of the present invention may exist in a number of manifestations, particularly with regards to the oxidation state of the central manganese atom. MALDI mass spectroscopy strongly indicates that the Mn^"2 oxidation state predominates due to the major peak observed at mass 1945, but minor peaks at mass 1962 and mass 1980 may be the result of higher oxidation states. These higher oxidation states may include R₁₆Mn(O), R₁₆MnOH, R₁₆MnOOH, R₁₆Mn(OH)₂, and R₁₆Mn(O)OH, where R is neopentoxy. Whether these minor peaks are due to impurities in the compound itself or are a result of the vaporization process in the MALDI experiment itself could not be ascertained at the present time. Cyclic voltammetry, on the other hand, corroborates the structure of R₁₆Mn, but may show waves corresponding to a dimer of the manganese phthalocyanine, normally regarded as a μ-oxo dimer, R₁₆MnOMnR₁₆. The MALDI mass spectrum, however, does not exhibit a dimer peak as would be expected. In an attempt to distinguish between R₁₆Mn and R₁₆MnOMnR₁₆, a gel permeation chromatograph was performed using Biobeads™ X3 and tetrahydrofuran as solvent, on a mixture of R₁₆Mn and the related R₁₆Ni compound which cannot form a μ-oxo dimer. Although some small separation occurred, the results were inconclusive.

[0042] Examples of the phthalocyanines of the invention and methods of preparing them are illustrated below. It will be understood that the following examples are provided for illustration only and are not intended to limit the scope of the present invention in any manner.

[0043] Example 1: Synthesis of Manganese Hexadecaneopentoxyphthalocyanine

[0044] Example 1 will be described with reference to Figure 1.

[0045] Step (a): Synthesis of Magnesium Hexadecaneopentoxyphthalocyanine

[0046] Magnesium alkoxides of long chain alcohols are not readily synthesized from the metal, but can be easily prepared from a suitable Grignard reagent. To approximately 2 ml of 1-octanol, was added 1.5 ml of 1.0M phenyl magnesium bromide solution in THF, during which heat was liberated. After 15 minutes of stirring to ensure the complete reaction of the Grignard reagent, 3,4,5,6-tetraneopentoxyphthalonitrile (11) was added, and the reaction mixture was heated to 120°C for a period of 4 days. The resulting green material (10) was confirmed to be the desired magnesium hexadecaneopentoxyphthalocyanine by mass spectrometry (MS) (MALDI, M⁺ = 1914.0), UN-visible (λ_max= 754mn) and 1H ΝMR spectroscopy. The absoφtion spectrum for the magnesium hexadecaneopentoxyphthalocyanine is illustrated in Figure 2.

[0047] Step (bV. Synthesis of Metal-Free Hexadecaneopentoxyphthalocyanine

[0048] After synthesis of the magnesium phthalocyanine (10) of Step (a), preparation of a metal-free compound was conducted. The magnesium phthalocyanine (10) was dissolved in 5 ml of glacial acetic acid and refluxed for 3 days. The process provided a good yield of metal-free 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecaneopentoxyphthalocyanine (16). Definite changes were observed in the Q-band region of the UN-visible spectrum which indicated that the metal-free phthalocyanine (16) had indeed been prepared. This was further supported by both the mass spectrum (MALDI, M⁺ = 1892.5) and the 1H NMR spectrum. The absoφtion spectrum for the metal-free hexadecaneopentoxyphthalocyanine is illustrated in Figure 3.

[0049] Step (cl): Synthesis of Lead Hexadecaneopentoxyphthalocyanine

[0050] From the metal- free phthalocyanine (16), metallated phthalocyanines were prepared by treating the metal free phthalocyanine with appropriate metal salts in refluxing N,N-dimethylformamide (DMF) or N,N,-dimethylaminoethanol (DMAE). In the case of lead hexadecaneopentoxyphthalocyanine, an excess of lead (II) acetate and 10 mg of metal-free hexadecaneopentoxyphthalocyanine (16) were dissolved in 2 mL of DMF and refluxed for 72 hours to produce a hexadecaneopentoxyphthalocyaninato lead complex. The resulting light green compound was precipitated out of solution using acidified 95% ethanol: water, washed once with methanol, once with water and finally once again with methanol. The resulting compound was found to have the following characteristics indicative of the desired end product: melting point (mp) >300°C; UN-vis λ_max (THF): 800 nm; MALDI-MS m/z (relative intensity): 2097.1 (M⁺, 100). The absoφtion spectrum for the lead hexadecaneopentoxyphthalocyanine is illustrated in Figure 4.

[0051] Step (c2 : Synthesis of Manganese Hexadecaneopentoxyphthalocyanine

[0052] Metal-free hexadecaneopentoxyphthalocyanine (16), in an amount of 80mg, was refluxed in 3 ml DMF with excess manganese (II) acetate. After 48 hours, the reaction mixture was allowed to cool to room temperature, and the reddish-brown reaction mixture was purified by flash silica gel column chromatography using toluene as the eluting solvent. The resulting amoφhous red solid was then further purified by size exclusion chromatography using toluene as the eluent. A final flash silica gel column was carried out, using toluene as the eluting solvent to give the desired manganese phthalocyanine as a red solid in 14% yield (12mg) having the following characteristics: mp >300°C; UN-vis λ_max (THF): 828 nm; MALDI-MS m/z (relative intensity): 1945.3 (M^1", 100). Further, for the desired compound (C₁₁₂H_{1 6}O₁₆Ν₈Mn) the theoretical chemical analysis was calculated as: C: 69.14; H: 9.12; and N: 5.76. The analysis of the product was found to be: C: 68.46; H: 9.12; and N: 5.28. This confirmed the presence of the expected compound. The absoφtion spectrum for the manganese hexadecaneopentoxyphthalocyanine is illustrated in Figure 5.

[0053] Example 2: Synthesis of Manganese Hexadeca(cyclohexylmethyloxy)phthalocyanine

[0054] Step (a): Synthesis of Tetra(^"cyclohexylmethyloxy phthalonitrile

[0055] In 15 ml of DMF were dissolved 500 mg of tetrafluoronitrile (2.5 mmol), 7 g of cyclohexylmethanol (62 mmol) and 8.6 g of potassium carbonate (62mmol). The mixture was heated to 110 °C for 5 days. After this period, the reaction mixture was poured into 200 ml of water and extracted with 3 x 50 ml of ether. The combined ether layers were washed with 100 ml of water followed by 100 ml of brine. After drying over sodium sulfate, the solvent was removed and the remaining oily material purified by flash silica gel chromatography using a mixture of dichloromethane:methanol = 20: 1 as the eluting solvent. The first fraction was collected and the solvent was evaporated. The resulting yellow solid (1 g, yield: 70%), which had a melting point of 70 - 72 °C, was confirmed to be the desired product by ^!H NMR spectroscopy, IR spectroscopy and EI-MS (M⁺ = 576.39).

[0056] Step (M : Synthesis of Nickel Hexadeca(cvclohexylmethyloxy phthalocyanine

[0057] In 3-4 ml of DMAE, 200 mg of 3,4,5,6-tetra(cyclohexylmethyloxy)phthalonitrile and 35 mg of NiCl₂x6H₂O were dissolved and heated to 145 °C for 24 hours. The resulting green material was precipitated into water and washed with methanol twice. Further purification was obtained by flash silica gel chromatography using hexane:efhylacetate = 4:1 as the eluting solvent. The first fraction (green) was confirmed to be the desired nickel Pc by MALDI-MS (M* = 2362.7), UN-vis (λmax = 736 nm), and 1H ΝMR spectroscopy. The yield of the product was 2% (3.5 g). The absoφtion spectrum for the nickel hexadeca(cyclohexylmethyloxy)phthalocyanine is illustrated in Figure 6. [0058] Step 0)2 : Synthesis of Magnesium Hexadeca(cvclohexylmethyloxy)phthalocvanine

[0059] To approximately 2 ml of 1-octanol, was added 1.0 ml of 1.0M phenyl magnesium bromide solution in THF. After 15 minutes of stirring to ensure the complete reaction of the Grignard reagent to form the magnesium alcoxide, 250 mg of 3,4,5,6 tetra(cyclohexylmethyloxy)phthalonitrile was added. The reaction mixture was heated to 120 °C for 24 hours. The resulting material was precipitated out of solution using acidified 95% ethanol: water, and washed twice with water. The green solid (130 mg, yield = 51%) was confirmed to be the desired end product by mass spectroscopy (MS) (MALDI, M⁺ = 2330.1), UN-vis (λmax = 734 nm), and 1H ΝMR spectroscopy. The absoφtion spectrum for the magnesium hexadeca(cyclohexylmethyloxy)phthalocyanine is illustrated in Figure 7.

[0060] Step (c): Synthesis of Metal-Free Hexadeca(cyclohexylmethyloxy)phthalocyanine

[0061] The magnesium hexadeca(cyclohexylmethyloxy)phthalocyanine (125 mg) was dissolved in 4 ml of glacial acetic acid and refluxed for 4 days. After this period, the product was precipitated out of solution using 95% ethanol: water, and washed twice with methanol. This procedure resulted in a green solid with a 77% yield (95 mg). Definite changes were observed in the Q-band region of the UN- visible spectrum that indicated that the metal-free Pc had indeed been prepared (UN-vis λmax = 764 nm). This was further supported by both the mass spectrum (MALDI, M⁺ = 2307.9) and the 1H ΝMR spectrum. The absoφtion spectrum for the metal-free hexadeca(cyclohexylmethyloxy)phthalocyanine is illustrated in Figure 8.

[0062] Step (d : Synthesis of Manganese Hexadeca(cyclohexylmethyloxy phthalocyanine

[0063] Metal-Free Hexadeca(cyclohexylmethyloxy)phthalocyanine, in an amount of 25 mg, was dissolved in 1-2 ml of DMF with a high excess of manganese (II) acetate. The mixture was heated to 130 °C for 48 hours. After cooling to room temperature, the reddish- brown material was precipitated out of solution using 95% ethanol: water, and washed twice with methanol. The resulting solid was then further purified by flash silica gel chromatography using THF as the eluting solvent. The red material (yield: approx. 90%) had the following characteristics indicative of the desired end product: UV-vis λmax = 808 nm; MALDI-MS M⁺= 2360.95. The absoφtion spectrum for the manganese hexadeca(cyclohexylmethyloxy)phthalocyanine is illustrated in Figure 9.

[0064] Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto. The entire disclosures of all references recited above are incoφorated herein by reference.

Claims

WHAT IS CLAIMED IS:

1. A compound having formula II; (II)

wherein:

- M is Ni, Pb or Mn; and

- R is the same or different and is chosen from the group consisting of: neopentoxy; cyclohexylmethyloxy; substituted or non-substituted, cyclic or non-cyclic alkoxy; and substituted or non-substituted benzyloxy.

2. The compound of claim 1 wherein said R groups are neopentoxy groups.

3. The compound of claim 1 wherein R is cyclohexylmethyloxy.

4. The compound of claim 1 wherein M is manganese.

5. The compound of claim 1 wherein said alkoxy is C or greater.

6. The compound of claim 1 wherein all R groups are the same.

7. The compound of claim 1 wherein said compound is manganese-

1 ,2,3,4,8,9, 10, 11 , 15, 16, 17, 18,22,23 ,24,25-hexadecaneopentoxyphthalocyanine.

8. The compound of claim 1 wherein said compound is manganese-

1 ,2,3 ,4,8,9, 10, 11 , 15, 16, 11, 18,22,23,24,25-hexadeca(cyclohexylmethyloxy)phthalocyanine.

9. The compound of claim 1 wherein said compound is nickel-

1 ,2,3,4,8,9, 10, 11 , 15, 16, 17, 18,22,23 ,24,25-hexadeca(cyclohexylmethyloxy)phthalocyanine.

10. The compound of claim 1 wherein said compound exhibits a maximum absoφtion (λ_ma ) at a wavelength greater than 800 nm.

11. A method for producing a metal hexadeca substituted phthalocyanine, comprising: a) providing a tetra substituted phthalonitrile; b) reacting said tetra substituted phthalonitrile with phenyl magnesium bromide to produce a magnesium hexadeca substituted phthalocyanine (10); c) treating the magnesium hexadeca substituted phthalocyanine to release the magnesium from the ring structure to result in a metal-free hexadeca substituted phthalocyanine (16); d) treating the metal-free hexadeca substituted phthalocyanine with a metal acetate (18) to result in a metal-hexadeca substituted phthalocyanine (20).

12. The method of claim 11 wherein said substituents are chosen from the group consisting of: neopentoxy; cyclohexylmethyloxy; substituted or non-substituted, cyclic or non-cyclic alkoxy, said alkoxy being C₃ or greater; and substituted or non-substituted benzyloxy.

13. The method of claim 12 wherein said metal is chosen from nickel, lead or manganese.

14. The method of claim 13 wherein said tetra substituted phthalonitrile includes substituents in positions 3, 4, 5, and 6.

15. The method of claim 14 wherein step (b) comprises a Grignard reaction.

16. The method of claim 15 wherein step (c) comprises dissolving said phthalonitrile in acetic acid.

17. The method of claim 16 wherein said substituents comprise neopentoxy groups, and wherein said tetra substituted phthalonitrile comprises 3,4,5,6-tetraneopentoxyphthalonitrile and wherein said hexadeca substituted phthalocyanine comprises hexadecaneopentoxyphthalocyanine.

18. The method of claim 16 wherein said substituents comprise cyclohexylmethyl groups and wherein said tetra substituted phthalonitrile comprises 3,4,5,6- tetra(cyclohexylmethyl)phthalonitrile and wherein said hexadeca substituted phthalocyanine comprises hexadeca(cyclohexylmethyl)phthalocyanine.

19. The phthalocyanine produced according to the method of claim 16, wherein said phthalocyanine comprises manganese- 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25- hexadecaneopentoxyphthalocyanine.

20. The phthalocyanine produced according to the method of claim 16, wherein said phthalocyanine comprises manganese- 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25- hexadeca(cyclohexylmethyloxy)phthalocyanine.

21. The phthalocyanine produced according to the method of claim 16, wherein said phthalocyanine comprises nickel- 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25- hexadeca(cyclohexylmethyloxy)phthalocyanine.