MXPA00003486A - Reduced oxidation state transition metal compounds useful as olefin polymerization catalysts - Google Patents

Abstract

This invention is directed to reduced oxidation state Group 4-6 metal compounds, preferably the first row metals in those groups, suitable for activation as polymerization catalysts and characterized by comprising a substituted hydrotris(pyrazolyl)borate ancillary ligand and a plurality of single or multidentate uninegative ligands, excluding cyclopentadienyl ligands. The invention includes a polymerisation process characterized by comprising contacting one or more monomers polymerizable by coordination or insertion polymerization under suitable polymerization conditions with theses catalyst compositions.

Description

METAL COMPOUNDS OF REDUCED OXIDATION STATE TRANSITION, USEFUL AS POLYMERIZATION CATALYSTS Technical Field I This invention relates to organometallic compounds which comprise a transition metal compound of groups 4-6, in which the metal is in a reduced oxidation state, and which when activated by co-catalytic compounds, are suitable olefin polymerization catalysts. BACKGROUND OF THE INVENTION Polymerization by coordination of olefinically unsaturated monomers is well known and has led to the great proliferation of thermoplastic compositions of matter from olefins, such as polyethylene, polypropylene and ethylene propylene rubber. The early pioneers used the early transition metal compounds, particularly those of group 4 metals, with activators such as alkyl aluminum compounds. Further developments extended this work to bulky auxiliary, ligand-containing (i.e.,? 5-cyclopentadienyl) transition metal compounds ("metallocenes"), with activators such as alkyl alumoxanes. The representative work that focuses the effects on polymeric molecular weight of substituted mono- and bis-metallocene compounds is described in EP-A 0 129 368 and its counterpart, U.S. Patent 5, 324, 8007 Monocyclopentadienyl Metallocene Compounds containing heteroatoms are described in U.S. Patent 5,057,475 and silicon bridged metallocene biscyclopentadienyl catalysts are described in U.S. Patent 5,017,714. Recent developments have shown the effectiveness of ionic catalysts "compounds of activated metallocene cations stabilized by compatible non-coordinating anions, see, for example, U.S. Patents 5,278,199 and 5,384,299 and WO 92/00333, each of which is incorporated by reference herein Metal transition metal polymerization catalyst systems of groups 5-10, where the active center of the transition metal is in a high oxidation state and stabilized by polyanionic auxiliary ligand systems , of low coordination number, are described in U.S. Patent 5,502,124 and its divisional, U.S. Patent 5, 504, 049. Suitable poly-anionic, low coordination number, auxiliary ligands include both bulky imides and carbolides. It is said that these are suitable alone or in combination with mono-anionic auxiliary ligands, such as cyclopentadienyl derivatives. Example 1 illustrates tris (pyrazolyl) borate vanadium oxide dichloride, a d vanadium compound, and polymerization of ethylene therewith.

Reduced 4-6 transition metal complexes, useful as polymerization catalysts, are described in WO 96/13529. These complexes comprise a multidentate monoanionic ligand and two mono-anionic ligands, optionally with additional ligands. Each example illustrates the use of titanium complexes having a cyclopentadienyl ligand. The hydrotry (pyrazolyl) borate is a recognized ligand in the art for organometallic compounds and its use for suitable compounds as catalysts, as described. See, for example, WO 97/23492 which discloses bidentate tris (pyrazolyl) borate ligands in metals of groups 8-10 used for low molecular weight polymers, and WO 97/17379 which discloses ligand systems which contain pyrazolyl substituted specifically for transition metals, examples illustrating compounds mainly dQ of group 4 metal. U.S. Patent 5,321,794 discloses ring-opening metathesis polymerization of cyclic olefins using catalysts with a hydrotris (pyrazolyl) borate derivative of molybdenum and tungsten in the oxidation states +4 or +5. With a few exceptions, the use of complexes of tris (pyrazolyl) borate ("Tp") involves metal centers d °, as observed. The only prior art prior art exemplifying a non-d ° metal complex, WO 97/17379 in comparative example 12, shows that it has extremely low activity and is essentially ineffective. Additional catalysts would be desirable to complement the technology described above, particularly those suitable for use as insertion polymerization catalysts for olefins. Disclosure of the Invention This invention is directed to metal compounds of groups 4-6 of reduced oxidation state (those having electronic configurations d1-d3), preferably the metals of the first row in those groups, suitable for activation as polymerization catalysts and characterized by comprising a substituted tris (pyrazolyl) borate auxiliary ligand and a plurality of mono or multi-dentate uni-negative ligands, excluding cyclopentadienyl ligands. The invention includes a polymerization process characterized by comprising contacting one or more polymerizable monomers by polymerization by coordination or insertion, under suitable polymerization conditions, with these catalyst compositions. - Description of the Drawings Figures 1-3 are traces by GPC (gel permeation chromatography) of polyethylene homopolymer products prepared with the catalyst of the invention [HB (3, 5-Me2Pz) 3] -VCl2 (thf ). Figure 1 is the trace for the product prepared in Example 9 at a polymerization temperature of 30"C. Figure 2 is the trace for the product prepared in Example 10 at a polymerization temperature of 60" C. Figure 3 is the trace for the product prepared in Example 11 at a polymerization temperature of 115"C. Best Mode v Examples of the Invention The metal compounds of the invention, described above, can be represented generically by the following formula chemistry: TpMXnLp where Tp is a tris (pyrazolyl) borate substituted ligand; M is a transition metal of groups 4-6; X is independently halogen, alkoxide, aryloxide, amide, phosphide, hydride, hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl; organometaloid hydrocarbyl or substituted halocarbyl, or two groups are attached and linked to the primary ligand or transition metal to form a ring structure, or one or more groups may contain a neutral donor group; L is a neutral donor group that stabilizes the complex; n is a number that is determined by counterbalancing the charge on the metal such that the metal remains in a reduced oxidation state and the overall charge in the precursor complex is neutral; p is a number from 1 to 3, as necessary to stabilize the compound. The substitution in the ligand Tp can be any member of the group defined by X in the above definition, and preferably they are hydrocarbyl fractions with more preference C1-C6. The following figures: where each one was defined before. Each of R ', R ", R"' and R "" is independently defined as X before, as long as one of R ', R "or R"' is not hydride. The source compounds for the neutral donor groups L include any neutral compounds of Lewis base, capable of donating a pair of electrons to the center of the metal. Non-limiting examples include diethyl ether, trimethylamine, tetrahydrofuran, dimethylaniline, aniline, trimethylphosphine, n-butylamine, and the like. A suitable catalyst precursor, illustrative of this invention is [HB (3, 5-Me2C3N2H) 3] MC12 (C4H80), where = Ti, V, Cr. The catalyst compounds of the invention can be prepared in high yields using synthetic routes organometallic, as illustrated in the attached examples.

The metal compounds according to the invention can be activated for insertion polymerization catalysis by known methods for either Ziegler-Natta or metallocene transition metal compounds for coordination polymerization by including at least one linker ligand sigma with ligand-reactive metal and at least a single vacant orbit adjacent (cis) to ligand linked sigma, as achieved by activation. Traditional activators of the coordination polymerization technique are suitable, those typically including Le acids such as Ziegler organometallic co-catalysts and alumoxane compounds, and ionizing, ionizing precursor compounds, which extract a ligand so as to ionize the center of the molecule. metal to a cationic complex and provide a noncoordinating or weakly counterbalancing anion. The Ziegler co-catalyst will typically be an organometallic compound of a metal of groups 1, 2, 12 or 13 of the Periodic Table of the Elements. Preference is given to organoaluminum compounds selected from the group consisting of aluminum alkyl and aluminum alkyl halide. These can be represented by the formula: A1 (R2) 5X'3_S where R2 is independently a hydride or hydrocarbyl radicals Cx to C? N including aliphatic, alicyclic or aromatic hydrocarbon radicals, X 'is halogen and s is an integer of 1 to 3; and A12R23X'3, which are sesqui-halides of hydrocarbyl-aluminum. Examples include triethylaluminum, triisobutyl-aluminum, aluminum diethyl chloride, Al2Et3Cl3 and Ala (i-Bu) 3C13. Alkylalumoxanes and modified alkylalumoxanes are suitable as catalyst activators, particularly for the metal compounds of the invention comprising halide ligands. The alumoxane component useful as a catalyst activator is typically an oligomeric aluminum compound represented by the general formula (R "-Al-0) n, which is a cyclic compound, or R" (R "-Al-0) nAlR" 2 , which is a linear compound. In the general formula of alumoxane, R "is independently a C ± to C10 alkyl radical, for example methyl, ethyl, propyl, butyl or pentyl, and" n "is an integer from 1 to about 50. Most preferably, R "is methyl and" n "is at least 4. The alumoxanes can be prepared by various methods known in the art. For example, an aluminum alkyl can be treated with water dissolved in an inert organic solvent, or it can be contacted with a hydrated salt, such as hydrated copper sulfate suspended in an inert organic solvent, to yield an alumoxane. Generally, no matter how it is prepared, the reaction of an aluminum alkyl with a limited amount of water results in a mixture of the linear and cyclic species of the alumoxane. Methylalumoxane and modified methylalumoxanes are preferred. For additional descriptions, see U.S. Patent Nos. 4,665,208; 4,952,540; ,041,584; 5,091,352; 5,206,199; 5,204,419; 4,847,734; 4,924,018; 4,908,463; 4,968,827; 5,329,032; 5,248,801; 5,235,081; 5,157,137; 5,103,031; and EP 0 561 476 Al, EP 0 279 586 Bl, EP 0 516 476 Al, EP 0 594 218 Al, and WO 94/10180, each being incorporated herein by reference. When the activator is an alumoxane, the preferred molar ratio of transition metal compound to activator is from 1: 2,000 to 10: 1, more preferably from about 1: 500 to 10: 1, even more preferably from about 1: 250 to 1: 1, and most preferably from about 1: 100 to 1: 1. The term "non-coordinating anion" is recognized to mean an anion that either does not coordinate with the metal cation, or is only weakly coordinated with it, thereby remaining sufficiently labile to be displaced by a neutral Lewis base, such as a olefinic or acetylenically unsaturated monomer. Descriptions of ionic catalysts, those comprising a cationic transition metal complex and a non-coordinating anion, suitable for coordination polymerization, appear in the early works of US patents 5,064,802; 5,132,380; 5,198,401; 5,278,119; 5,321,106; 5,347,024; 5,408,017; 5,599,671, and the international publications WO 92/00333 and WO 93/14132. These teach a preferred method of preparation wherein the metallocenes are protonated by non-coordinating anion precursors so that an alkyl / hydride group is extracted by protonation of a transition metal to make it both cationic and balanced charge by the non-coordinating anion. As the extraction and insertion ligands of such metallocenes can also be ligands of the metal compounds of the invention, similar methods of preparing active polymerization catalyst components can be followed. It is also useful to use ionizing ionic compounds that do not contain an active proton but capable of producing both a cationic complex of active metal and a non-coordinating anion. See EP-A-0 426 637, EP-A-0 573 403, and U.S. Patent 5,387,568 for instructive ionic compounds. Reactive cations of ionizing ionic compounds, other than Bronsted acids, include ferrocenium, silver, tropylium, triphenylcarbenium and triethylsilyl, or alkali metal or alkaline earth metal cations such as sodium, magnesium or lithium cations. An additional class of non-coordinating anion precursors according to this invention are the hydrated salts comprising the alkali metal or alkaline earth metal cations and a non-coordinating anion, as described above. The hydrated salts can be prepared by reaction of the non-coordinating metal cation salt-anion with water, for example by hydrolysis of commercially available or easily synthesized LiB (pfp) 4, which yields [Li * xH20] [B (? Fp) 4], wherein (pfp) is pentafluorophenyl or perfluoro-phenyl. Any metal or metalloid capable of forming a coordination complex that is resistant to degradation by water (or other Bronsted or Lewis acids) can be used or contained in the noncoordinating anion. Suitable metals include, but are not limited to, aluminum, gold, platinum and the like. Suitable metalloids include, but are not limited to, boron, phosphorus, silicon, and the like. The description of the non-coordinating anions and their precursors in the documents of the preceding paragraphs is incorporated by reference. A further method of making the active polymerization catalysts of this invention uses ionizing anion precursors, which are initially neutral Lewis acids but form a cationic metal complex and the non-coordinating anion upon the occurrence of an ionizing reaction with the compounds of the invention. , for example tris (pentafluorophenyl) boron acts to extract a hydrocarbyl, hydride or silyl ligand to yield a metal cation complex of the invention and stabilizing non-coordinating anion, see EP-A-0 427 697 and EP-A-0 520 732 for illustration using metallocene compounds of group 4 analogues. See also the methods and compounds of EP-A-0 495 375. The description of non-coordinating anions and their precursors in these documents is similarly incorporated by reference. When the cation portion of a non-coordinating ionic anion precursor is a Bronsted acid such as protonated protons or Lewis bases (excluding water), or a reducible Lewis acid, such as ferrocenium or silver cations, or metal cations alkaline or alkaline earth metal such as those of sodium, magnesium or lithium, the molar ratio of transition metal to activator can be any ratio, but preferably from about 10: 1 to about 1:10, more preferably about from 5: 1 to 1: 5, even more preferably from about 2: 1 to 1: 2, and most preferably from about 1.2: 1 to 1: 1.2, with a ratio of about 1 being most preferred. :1. The catalyst complexes of the invention are useful in the polymerization of unsaturated monomers conventionally known as polymerizable under polymerization conditions by coordination using metallocenes. Such conditions are well known and include solution polymerization, slurry polymerization, gas phase polymerization, and high pressure polymerization. The catalyst of the invention can be supported and as such will be particularly useful in known modes of operation employing fixed bed, moving bed, fluid bed, or slurry processes conducted in single, series, or parallel reactors. When the catalysts of the invention are used, particularly when immobilized on a support, the total catalyst system will generally additionally comprise one or more stripping compounds. The term "stripping compounds", as used in this application and its claims, is intended to include those compounds effective to remove polar impurities from the reaction environment. The impurities can be accidentally introduced with any of the polymerization reaction components, particularly with the solvent, monomer and catalyst feed, and adversely affect the activity and stability of the catalyst. They can result in reducing or even eliminating the catalytic activity, particularly when ionizing anion precursors activate the catalyst system. Polar impurities, or catalyst poisons, include water, oxygen, metal impurities, etc. Preferably, steps are taken prior to the delivery of such to the reaction vessel, for example by chemical treatment or careful separation techniques after or during the synthesis or preparation of the various components, but some minor amounts of stripping compound will still normally be used in the polymerization process itself. Typically, the stripping compound will be an organometallic compound such as the organometallic compounds of group 13 of U.S. Patents 5,153,157, 5,241,025 and WO 91/09882, WO 94/03506, WO 93/14132 and WO 95/07941. Exemplary compounds include triethyl aluminum, triethyl borane, triisobutyl aluminum, methylalumoxane, isobutyl alumoxane, and n-octyl aluminum. Those stripping compounds having bulky hydrocarbyl or linear C6-C20 substituents, covalently linked to the metal or metalloid center, are preferred to minimize adverse interaction with the active catalyst. Examples include triethylaluminum but, more preferably, bulky compounds such as triisobutylaluminum, triisoprenylaluminium and linear, long-chain alkyl substituted aluminum compounds, such as tri-n-hexylaluminum, tri-n-octylaluminum or tri-n-dodecylalu-minium When alumoxane is used as an activator, any excess over the amount needed to activate the catalysts present will act as stripping compounds, and additional stripping compounds may not be necessary Alumoxanes may also be used in stripping quantities with other activation media, example methylalumoxane and isobutyl-alumoxane The amount of stripping agent to be used with the catalyst compounds of the groups 4-6 of the invention is minimized during polymerization reactions to that amount effective to increase the activity and is avoided altogether if the feeds can be sufficiently free of upstart impurities. The aligner according to the invention can be supported for use in gas phase polymerization processes, in bulk, in slurry, or otherwise as needed. Numerous methods of support for olefin copolymerization processes are known in the art, particularly for catalysts activated by alumoxanes, any being suitable for the process of the invention in its broadest ranges. See, for example, United States Patents 5,057,475 and 5,227,440. An example of the supported ionic catalysts appears in the publication WO 94/03056. A particularly effective method is that described in U.S. Patent 5,643 *, 847 and WO 96/04319. A bulk process, or in slurry, which uses metal compounds of groups 4-6 of the invention activated with alumoxane co-catalysts may be used as described for ethylene-propylene rubber in U.S. Patents 5,001,205 and 5,229,478. "These processes will additionally be suitable with the catalyst systems of this application." Both inorganic oxide and polymeric supports can be used in accordance with the knowledge in the field, see U.S. Patents 5,422,325.; 5,427,991; 5,498,582; 5,466,649, pending patent applications of the United States 08 / 265,532 and 08 / 265,533, both filed June 24, 1995, and international publications WO 93/11172 and WO 94/07928. Each of the above documents is incorporated by reference. In preferred embodiments of the process for this invention, the catalyst system is employed in liquid phase (solution, slurry, suspension, bulk phase or combinations thereof), in liquid phase at high pressure or in supercritical fluid, or in gas phase. Each of these processes can be used in singular reactors, in parallel or in series. The liquid processes comprise contacting olefin monomers with the catalyst system described above in a suitable diluent or solvent and allowing said monomers to react for a sufficient time to produce the homopolymers or copolymers of the invention. Hydrocarbyl solvents are suitable, both aliphatic and aromatic, with hexane and toluene being preferred Halocarbon solvents, for example methylene chloride, will be additionally suitable Bulk and slurry processes are typically carried out by contacting them. the catalysts with slurry of liquid monomer slurry, the catalyst system being supported The gas phase processes typically use a supported catalyst and are conducted in any manner known to be suitable for prepared ethylene homopolymers or copolymers by means of coordination polymerization. Illustrative examples can be found in U.S. Patents 4,543,399; 4,588,790; 5,028,670; 5,382,638; 5,352,749; 5,436,304; 5,453,471; and 5,463,999, and WO 95/07942. Each of these is incorporated herein by reference. Generally speaking, the temperature of the polymerization reaction can vary from about -50 to about 250 * C. Preferably, the reaction temperature conditions will be from -20 to 220 ° C, more preferably less than 200 'C. The pressure may vary from about 1 mm Hg to 2,500 bars, preferably from 0.1 to 1.600 bar , most preferably from 1.0 to 500 bar.Where lower molecular weight copolymers are sought, for example Mn less than 10,000, it will be suitable to conduct the reaction processes at temperatures around 0 ° C and pressures below 500 bar. The multi-boron activators of U.S. Patent 5,278,119 can be further employed to facilitate the preparation of the low molecular weight copolymers of the invention. Advantageously, the behavior of the ligand in the coordination environment around the center of the metal allows the easy preparation of mixed polymeric physical mixtures with a single metal compound according to the invention in a single polymerization reactor. One method of custom designing the properties of a polymer resin is to physically mix a set of different polymers, each having a distinctive combination of properties, into a homogeneous product with a new combination of properties distinguishable from those of the individual components. These products can be useful for applications such as film, bottle and pipe resins in conjunction with blow molding processes. The components with high Mw add resistance to the physical mixture, while the components with low Mw add processing capacity. The ability to control the relative ratio of components in the physical mixture would allow optimizing properties such as tear strength. The formation of these physically mixed polymers can be achieved ex by physical mechanical mixing or by using a mixed catalyst system. It is generally believed that physical mixing in itself provides a homogeneous product and allows the physical mixture to be produced in one step. The use of mixed catalyst systems for physical mixing in itself involves combining more than one catalyst in the same reactor to simultaneously produce different polymer products. This method requires additional catalyst synthesis and the various catalyst components must be matched in terms of their activities, polymeric products that generate specific conditions, and their response to changes in polymerization conditions. An alternative to using catalyst mixtures is to use a single catalyst precursor that can generate more than one active form in the reactor. This would allow the generation of physical mixtures in situ without requiring the synthesis of multiple catalysts. The catalysts of the invention contain components that can show lability. Various variable temperature NMR studies can verify the lability of the ligand components in metal complexes, and neutral donor ligands, as they exist in the catalysts of the invention, generally show the highest degree of lability. In addition, compounds containing tris (pyrazolyl) borate ligands are known in which the ligand can take any of several coordination modes, bi-toothed and tri-toothed coordination being the most common. There is also evidence, in Carrano and collaborators. { Inorg. Chem. , 1989, 28, 4392), that the ligand can be converted between different modes of coordination into a single molecule. Thus, it is possible that a neutral donor ligand or a component of the multi-toothed ligand system of the catalysts of the invention show lability under reaction conditions. With this behavior, a typical catalyst precursor of the invention forms a kind of active catalyst that incorporates the labile component that can be dissociated or extracted during the polymerization to form additional active catalyst species. The final polymeric physical mixture is then determined by the relative populations of the individual catalyst species in the reactor. The degree or rate of dissociation or extraction of the labile components can be controlled by thermal, photochemical or electrochemical methods or by the addition of additional external donor species having the same or different identity as the labile components or external acceptor species that can extract the labile component from the center of the metal. Examples 9-11 below illustrate physical polydispersity polyethylene mixtures achieved with a single metal compound of the invention used at different polymerization temperatures. Linear polyethylene, including high and ultra-high molecular weight polyethylenes, including both homopolymers and copolymers with other alpha-olefin monomers, alpha-olefinic and / or unconjugated diolefins, for example C3-C20 olefins, diolefins or cyclic olefins, is produced by adding ethylene, and optionally one or more of the other monomers, to a reaction vessel under a low pressure (typically less than 50 bar), at a typical temperature of 20 to 250 ° C with the catalyst of the invention which has been put in slurry with a solvent, such as hexane or toluene The polymerization heat is typically removed by cooling Gas phase polymerization can be conducted, for example, in a continuous, fluid gas phase reactor operated at 2,000-3,000 kPa ^ and 60-160 * C, using hydrogen as a reaction modifier (100-200 ppm), a C4-C8 co-monomer feed stream (0.5-1.2 mol%), and a C2 feed stream (2). 5-35 molar%) See U.S. Patents 4,543,399; 4,588,790, r 5,028,670; 5,405,922; and 5,462,999, which are incorporated herein by reference. Ethylene-alpha-olefin elastomers (including ethylene-cyclic olefin and ethylene-alpha-olefin-diolefin) of high molecular weight and low crystallinity can be prepared using the catalysts of the invention under traditional solution polymerization processes, or by introducing ethylene gas into a slurry using the alpha-olefin or cyclic olefin or "mixture thereof with other monomers, polymerizable and not, as a polymerization diluent in which the catalyst of the invention is suspended.Typical ethylene pressures will be between 10 and 1,000 psig (gauge) (69-6,895 kPa) and the temperature of the polymerization diluent will typically be between -10 and 160 * C. The process may be carried out in a stirred tank reactor, or more than one reactor operated in series or In parallel, see the general disclosure of the United States patent 5,001,205 for general process conditions. United States Serial No. 08 / 426,363, filed April 21, 1995 and 08 / 545,973, filed October 20, 1995. All documents are incorporated by reference with respect to the description of polymerization processes, ionic activators and compounds useful disposers. Pre-polymerization of the supported catalyst of the invention can also be used for further control of the particle morphology of the polymer in typical slurry or gas phase reaction processes, in accordance with conventional teachings. For example, this can be achieved by pre-polymerizing a C2-C6 alpha-olefin for a limited time, for example, ethylene is contacted with the supported catalyst at a temperature of -15 to 30 ° C and an ethylene pressure of up to about 250 psig (1,724 kPa) per 75 minutes, to obtain a polymeric coating on the polyethylene support of molecular weight of 30,000-150,000.The pre-polymerized catalyst is then available for use in the aforementioned polymerization processes. The use of polymeric resins as a support coating can be further considered, typically by suspending a solid support in dissolved resin from a material such as polystyrene, with subsequent separation and drying.All documents are incorporated by reference with respect to the description of metallocene, ionic activators and useful stripping compounds Other olefinically unsaturated monomers, in addition to those described s previously specifically, they can be polymerized using the catalysts according to. invention, for example styrene, substituted alkyl styrene, ethylidene norbornene, norbornadiene, dicyclopentadiene, and other olefinically unsaturated monomers, including other cyclic olefins, such as "cyclopentene, norbornene, and substituted alkyl norbornenes." Furthermore, they can also be incorporated by "macro copolymerization". alpha-olefinic monomers up to 100 mer units or more. The catalyst compositions of the invention can be used as described above for coordination polymerization or can be mixed to prepare polymeric physical mixtures with other known olefin polymerization catalyst compounds. By selecting monomers, physical mixtures of coordination catalyst compounds, polymeric physical mixtures can be prepared under polymerization conditions analogous to those using individual catalyst compositions. In this way, polymers having an increased molecular weight distribution for improved processing and other traditional benefits available from polymers made with mixed catalyst systems can be achieved. The following examples are presented to illustrate the previous discussion. All parts, proportions and percentages are by weight, unless otherwise stated. All the examples are carried out in environments and dry solvents, free of oxygen. Although the examples may be directed to certain embodiments of the present invention, they should not be viewed as limiting the invention in any specific respect. In these examples, certain abbreviations are used to facilitate the description. These include standard chemical abbreviations for the elements and certain commonly accepted abbreviations, such as: Me = methyl, Pz = pyrazolyl, and THF or thf = tetrahydrofuran. All molecular weights are weighted average molecular weights unless otherwise indicated. Molecular weights (heavy average molecular weight (Mw) and numerical average molecular weight (Mn)) were measured by gel permeation chromatography, unless otherwise indicated, using a Waters 150 gel permeation chromatograph, equipped with a differential refractive index detector and calibrated using polystyrene standards. The samples were run either in THF (45"C) or in 1, 2, 4-trichlorobenzene (145" C), depending on the solubility of the sample, using three Shodex GPC AT-80 M / S columns in series. This general technique is discussed in "Liquid Chro atography of Polymers and Related Materials III," J. Cazes, "editor, Marcel Dekker, 1981, page 207, which is incorporated herein by reference." No column spreading corrections were employed.; however, data in generally accepted standards, for example polyethylene 1475 from the National Bureau of Standards, showed an accuracy of 0.1 units for Mw / Mn, which was calculated from the elution times. The numerical analyzes were carried out using Expert Ease software, available from Waters Corporation. EXAMPLES Example 1 Synthesis of [HB (3, 5-Me2Pz) 3] TiCl2 (thf). K [HB (3, 5-Me2Pz) 3] (1.82 g, 5.41 mmol) was slowly added to a suspension of TiCl3 (thf) 3 (2.00 g, 5.40 mmol) in thf (30 ml) During the addition, the color changed from light blue to deep green and then to blue-green After stirring at room temperature for 3 days, the Volatile materials were removed from the dark blue mixture.The solid residue was extracted with CH2C12 (30 mL) and filtered.The solution was concentrated to 5 mL and pentane (40 mL) was added slowly to precipitate the product. one glass and washing with pentane (2 x 20 ml) The residual solvent was removed under reduced pressure, leaving the product as a blue powder (2.15 g, 4.40 mmol, 82%) Elemental analysis, IR spectrum, and momentum The magnetic compound was consistent with the title compound Example 2 Synthesis of [HB (3, 5-Me2Pz) 3] VC12 (thf) The title compound was synthesized in a manner similar to the Ti analogue from K [HB (3, 5-Me2Pz) 3] (1.80 g, 5.35 mmole) and VCl3 (thf) 3 (2.00 g, 5.35 mmole), except that the mixture of r The reaction was stirred for 18 hours. The process gave the product as a yellow-green powder (1.22 g, 2.48 mmoles, 46%). The elemental analysis, the IR spectrum, and the magnetic moment were consistent with the title compound. Example 3 Synthesis of [HB (3, 5-Me2I? Z) 3] CrCl2 (thf). The title compound was synthesized in a manner similar to the Ti analogue from K [HB (3,5-Me2Pz) 3] (0.90 g, 2.7 mmol) and CrCl3 (thf) 3 (1.00 g, 2.67 mmol), except that the reaction mixture was stirred for one day. The process gave the product as a light green powder (0.81 g, 1.6 mmol, 62%). The elemental analysis, the IR spectrum, the magnetic moment, and the X-ray crystallographic data were consistent with the title compound. General polymerization method (Examples 4-17). Polymerizations were carried out in a 500 ml Zipperclave reactor, purged with hot nitrogen (Autoclave Engineers) in dry hexane (250 ml) as solvent / polymerization diluent. The co-catalyst used was methylalumoxane (MAO) in a 10% toluene solution. Typically, 2.5 ml was diluted with fresh toluene before injection to the rector. The hexane in the reactor was then saturated with ethylene at the designated pressure and temperature, and co-monomer was added, if any. The catalyst solution was prepared in the dry box by mixing 5 to 50 mg of catalyst precursor with toluene (50 ml). The catalyst precursor solution was pumped into the reactor, and combined with the co-catalyst solution previously added, until the flow of ethylene formation becomes constant during the polymerization. The temperature of the reactor was controlled by a mixture of water vapor / cooling water flowing through the reactor jacket. The polymerization was run for 30 minutes. In the end, ethylene was vented and the reactor was cooled. The contents of the reactor were poured into a 1 1 flask and treated with isopropyl alcohol or acetone. The polymer solvent mixture was blown down with nitrogen or filtered to recover the polymer. The final product was dried under vacuum at 60-90"C for about 12 hours.The samples were analyzed by GPC for molecular weight and polydispersity and by 1 H NMR for branching in copolymerizations. ~ Example 4 Polymerization of ethylene with [HB (3,5-Me2Pz) 3] TiCl2 (thf) at 30 * C.

A total of 13.0 mg of [HB (3, 5-Me2Pz) 3] TiCl2 (thf) in toluene solution was pumped into a 500 ml stainless-steel reactor containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene, and 76 psi of ethylene. The polymerization was run for 30 minutes while the reactor was maintained at 30 ° C and the subsequent process of the polymeric product gave 0.9 g of polyethylene with Mw = 6.99 x 105 and a polydispersity of 4.1 Example 5 Polymerization of ethylene with [HB (3 , 5-Me2Pz) 3] TiCl2 (thf) at 60"C. A total of 12.7 mg of [HB (3, 5-Me2Pz) 3] TiCl2 (thf) in solution in toluene was pumped into a 500 ml stainless steel reactor. containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene and 125 psi of ethylene. The polymerization was run for 30 minutes while the reactor was maintained at 60 ° C and the subsequent process of the polymeric product gave 1.4 g of polyethylene with Mw = 3.34 x 105 and a polydispersity of 9.2 Example 6 Polymerization of ethylene with [HB (3 , 5-Me2Pz) 3] TiCl2 (thf) at 115 * C A total of 24.0 mg of [HB (3, 5-Me2Pz) 3] TiCl2 (thf) in solution in toluene was pumped into a stainless steel reactor 500 ml containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene and 275 psi of ethylene The polymerization was run for 30 minutes while the reactor was maintained at 115"C and the subsequent process of the polymeric product gave 2.2 g of polyethylene with Mw = 3.07 x 105 and a polydispersity of 20.8. Example 7 Polymerization of ethylene with [HB (3, 5-Me2Pz) 3] TiCl2 (thf) at 140"C.

A total of 27.0 mg of [HB (3, 5-Me2Pz) 3] TiCl2 (thf) in solution in toluene was pumped into a 500 ml stainless steel reactor containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene and 375 psi of ethylene. The polymerization was run for 30 minutes while the reactor was maintained at 30 * C and the subsequent process of the polymeric product gave 3.5 g of polyethylene with Mw = 3.90 x 105 and a polydispersity of 21.3. Example 8 Polymerization of ethylene / 1-hexene with [HB (3,5-Me2Pz) 3] TiCl2 (th) at 60 * C. A total of 30.0 mg of [HB (3, 5-Me2Pz) 3] TiCl2 (thf) in "toluene solution was pumped into a 500 ml stainless steel reactor containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene, 15 ml of 1-hexene and 61 psi of ethylene The polymerization was run for 30 minutes while the reactor was maintained at 60 ° C and the subsequent process of the polymeric product gave 0.6 g of ethylene / hexene copolymer with Mw = 7.6 x 105, polydispersity of 7.6, and 8 branches / 1, 000 C. Example 9 Polymerization of ethylene with [HB (3, 5-Me2Pz) 3] VC12 (thf) at 30 'C. A total of 11.3 mg of [HB (3, 5-Me2Pz) 3] VC12 (thf) in solution in toluene was pumped into a 500 ml stainless steel reactor containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene and 75 psi of ethylene. The polymerization was run for 30 minutes while the reactor was maintained at 30 ° C and the subsequent process of the polymeric product gave 4.2 g of polyethylene with Mw = 6.89 x 105 and a polydispersity of 21.2 Example 10 Polymerization of ethylene with [HB (3 , 5-Me2Pz) 3] VC12 (thf) at 60 * C. A total of 8.2 mg of [HB (3, 5-Me2Pz) 3] VC12 (thf) in solution in toluene was pumped into a stainless steel reactor of 500 ml containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene and 125 psi of ethylene The polymerization was run for 30 minutes while the reactor was maintained at 60 ° C and the subsequent process of the polymeric product gave 1.8 g of polyethylene with Mw = 3.34 x 105 and a polydispersity of 29.2. Example 11 Polymerization of ethylene with [HB (3, 5-Me2Pz) 3] VC12 (th) at 115 * C. A total of 21.8 mg of [HB (3, 5-Me2Pz) 3] VC12 (thf) in solution in toluene was pumped into a 500 ml stainless steel reactor containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene and 275 psi of ethylene. The polymerization was run for 30 minutes while the reactor was maintained at 115 ° C and the subsequent process of the polymeric product gave 1.4 g of polyethylene with Mw = 9.3 x 104 and a polydispersity of 22.7 Example 12 Polymerization of ethylene with [HB ( 3.5-Me2Pz) 3] VC12 (th) at 140 'C.

A total of 8.8 mg of [HB (3, 5-Me2Pz) 3] VC12 (thf) in solution in toluene was pumped into a 500 ml stainless steel reactor containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene and 350 psi of ethylene. The polymerization was run for 30 minutes while the reactor was maintained at 140 * C and the subsequent process of the polymeric product gave 2.1 g of polyethylene with Mw = 3.34 x 105 and a polydispersity of 71.0. Example 13 Polymerization of ethylene / 1-hexes with [HB (3, 5-Me2Pz) 3] VC12 (thf) at 60'C. A total of 8.6 mg of [HB (3, 5-Me2Pz) 3] VC12 (thf) in solution in toluene was pumped into a 500 ml stainless steel reactor containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene, 15 ml of 1-hexene and 60 psi of ethylene. The polymerization was run for 30 minutes while the reactor was maintained at 60 * C and the subsequent process of the polymer product gave 1.2 g of polyethylene with Mw = 1.32 x 105, polydispersity of 15.2, and ~6 branches / 1, 000 C. Example 14 Polymerization of ethylene with [HB (3, 5-Me2Pz) 3] CrCl2 (thf) at 30"C. A total of 9.6 mg of [HB (3, 5-Me2Pz) 3] CrCl2 (thf) in toluene solution was pumped into a 500 ml stainless steel reactor containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene and 75 psi of ethylene, the polymerization was run for 30 minutes while the reactor was maintained at 30"C and the Subsequent processing of the polymeric product gave 0.4 g of polyethylene with Mw = 3.68 x 105 and a polydispersity of 60.8. Example 15 Polymerization of ethylene with [HB (3, 5-Me2Pz) 3] CrCl2 (thf) at 60"C.

A total of 12.8 mg of [HB (3, 5-Me2Pz) 3] CrCl2 (thf) in solution in toluene was pumped into a 500 ml stainless steel reactor containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene and 125 psi of ethylene. The polymerization was run for 30 minutes while the reactor was maintained at 60 ° C and the subsequent process of the polymeric product gave 1.0 g of polyethylene with Mw = 2.78 x 105 and a polydispersity of 34.6 Example 16 Polymerization of ethylene with [HB (3 , 5-Me2Pz) 3] CrCl2 (thf) at 115"C. A total of 28.2 mg of [HB (3, 5-Me2Pz) 3] CrCl2 (thf) in solution in toluene was pumped into a 500 ml stainless steel reactor containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene and 274 psi of ethylene. The polymerization was run for 30 minutes while the reactor was maintained at 115 ° C and the subsequent process of the polymeric product gave 1.1 g of polyethylene with Mw = 2.4 x 105 and a polydispersity of 14.1 Example 17 Polymerization of ethylene with [HB (3 , 5-Me2Pz) 3] CrCl2 (thf) at 140 * C A total of 29.7 mg of [HB (3, 5-Me2Pz) 3] CrCl2 (thf) in "toluene solution was pumped into a stainless steel reactor of 500 ml containing 250 ml of hexane, 2.5 ml of 10% MAO in toluene and 350 psi of ethylene The polymerization was run for 30 minutes while the reactor was maintained at 140 ° C and the subsequent process of the polymeric product gave 1.6 g polyethylene with Mw = 2.0 x 104 and a polydispersity of 10.1. Table 1 Performance Comparison ^ polymerization temperature, all the examples run as illustrated in the above examples The above examples illustrate a considerable improvement over the examples of the publication WO 97/17379, both with respect to catalyst productivities (AD vs. I, J) and in certain examples the activity that increases at higher polymerization temperatures. The publication WO 97/17379 also illustrates that the catalyst can be used to control the molecular weight distribution of the polymer, especially for bimodal products, and GPC graphs are provided for three examples. However, the distribution of molecular weights is controlled by changing the substitution pattern in the pyrazole rings. There is no explanation as to the mechanism. The examples of WO 97/17379 use three different structures run under the same polymerization conditions. The above examples use the same structure run under three different polymerization temperature conditions. Therefore, the phenomena of the publication WO 97/17379 are based on changes in the structure of the set of auxiliary ligands, while those of this invention are based on the lability of the ligand components in response to changing reactor conditions. Further, the catalysts of this invention do not specifically control the molecular weight distribution of the polymer, but instead control the relative amounts of polymer components in a physically mixed product that inherently has a broad molecular weight distribution, see figures 1-3. The use of reduced metal centers is significant for the present invention because the presence of additional electrons in the center of the metal, relative to complexes d °, can increase the lability of donor groups in the coordination sphere. Also, since pseudo-octahedral, six-coordinate geometries are extremely favorable for transition metals (especially early transition metals, deficient in electrons), most tris (pyrazolyl) borate complexes related to catalysis tend to have the form TpMX3, where the X ligands can be the same or different anionic ligands. Since ligand Tp generally occupies three coordination sites and ligands X occupy the other three coordination sites, they form pseudo-octahedral complexes without the presence of additional neutral donor ligands. However, for complexes not in an oxidation state +3, the charge on the metal can be balanced by a ligand Tp and two ligands X. This leaves a coordination site still available and, thus, allows the addition of the neutral donor ligand L. Therefore, by using non-d ° metals, complexes possessing an excess of potentially labile donor ligands, which are not available in the analogues d °, can be isolated.

Claims (10)

1. CLAIMS 1. Transition metal compounds suitable for activation in insertion polymerization catalyst complexes comprising a metal compound of groups 4-6 in reduced oxidation state, having a substituted tris (pyrazolyl) borate auxiliary ligand and a plurality of single or multi-dentate uni-negative ligands, excluding ligands containing cyclopentadienyl group, and at least one neutral donor group. The metal compounds of claim 1, wherein the metal of said metal compound of groups 4-6 is selected from the group consisting of Ti, V or Cr. 3. The metal compounds of claim 1, wherein said metal is vanadium. 4. The metal compounds of claim 1, wherein said metal compounds are represented by the structural formula: TpMXnLp wherein Tp is a substituted tris (pyrazolyl) borate ligand; M is a transition metal of groups 4-67; X is halogen, alkoxide, aryloxide, amide, phosphide, hydride, hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl; organometaloid hydrocarbyl or substituted halocarbyl, or two groups are attached and linked to the primary ligand or transition metal to form a ring structure, or one or more groups may contain a neutral donor group; L is a neutral donor group that stabilizes the complex; n is a number that is determined by counterbalancing the charge on the metal such that the metal remains in a reduced oxidation state and the overall charge in the precursor complex is neutral; p is a number from 1 to 3, as necessary to stabilize the compound. The metal compounds of claim 4, wherein M is selected group consisting of Ti, V or Cr. 6. The catalyst composition of claim 5, wherein said metal is vanadium. 7. The catalyst composition of claim 4, wherein said metal compound is reacted with an alkylalumoxane or alkyl aluminum co-catalyst activator. 8. The catalyst composition of claim 4, wherein said metal compound is reacted with a non-coordinating, ionizing precursor compound. 9. A polymerization process characterized in that it comprises contacting one or more polymerizable monomers by coordination polymerization under suitable conditions of polymerization by coordination with a catalyst composition according to any of claims 1- 10. A polymerization process characterized in that it comprises contacting one or more polymerizable monomers by coordination polymerization under suitable polymerization conditions by coordination with a catalyst composition according to claim 8.