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United States Patent (19) 11) 4,091,082 Gessell Et Al United States Patent (19) 11) 4,091,082 Gessell et al. 45 May 23, 1978 54 HYDROCARBON SOLUBLE CATALYST (III) Ammines Chemical Communications, 1970 pp. CONTAINING ONTROGEN OR 875-876 Elson et al. DHYDROGEN TRANSTION METAL The Interaction of Dinitrogen Complexer of Ruthe COMPLEX nium and Osmium with metal salts. Chemical Commu 75) Inventors: Donald Earl Gessell, Baton Rouge, nications, 1970, pp. 90–91, Chatt et al. La; Kirby Lowery, Jr., Lake Bioinorganic Chemistry, Advances in Chemistry Series Jackson, Tex. 100, 79 (1971), Allen. pp. 79-94. Bioinorganic Chemistry, Advances in Chemistry Series 73 Assignee: The Dow Chemical Company, 100, 95 (1971), "Fixation of Molecular Nitrogen Under Midland, Mich. Mild Cond. pp. 95-110. (21) Appl. No.: 693,071 Chemical Reviews, 73 11(1973) Allen et al. pp. 11-20. 22 Filed: Jun. 4, 1976 51) Int. C.? ....................... C01B 21/00; B01J 31/00; Primary Examiner-Patrick P. Garvin B01J 27/24: CO1B 11/00 Assistant Examiner-William G. Wright 52 U.S. C. ............................... 423/413; 252/429 A; Attorney, Agent, or Firm-J. G. Carter; M.S. Jenkins 252/429 B; 252/438; 42.3/472; 423/644; 526/159; 526/161; 526/164; 526/169 57 ABSTRACT 58) Field of Search ............... 252/429 A, 429 B, 438; 423/81, 413, 472, 644, 351 Hydrocarbon-soluble compositions useful as the transi tion metal component in the Ziegler polymerization of 56 References Cited a-olefins are provided by reacting molecular nitrogen U.S. PATENT DOCUMENTS or hydrogen with a transition metal compound such as 1,491,588 4/1924. Duparc et al. ....................... 252/438 titanium trichloride to form a dinitrogen or dihydrogen 3,403, 197 9/1968 Seelbach et al. .. ... 252/429 AX complex of the transition metal compound. OTHER PUBLICATIONS Dinitrogen Complexer of Osmium (III) and Ruthenium 7 Claims, No Drawings 4,091,082 1. 2 tion metal, anionic groups and molecular nitrogen and HYDROCARBON SOLUBLE CATALYST /or molecular hydrogen. With the exception of divalent CONTAINING DENITROGEN OR DIHYDROGEN nickel compounds, the transition metal of the complex TRANSTION METAL COMPLEX has an oxidation state or valence greater than two. In all complexes of this invention, the molecular nitrogen or BACKGROUND OF THE INVENTION molecular hydrogen forms a coordinate covalent bond This invention relates to new catalytic dinitrogen and with the transition metal. The anionic groups of the dihydrogen complexes of a transition metal and to a complex are preferably halide, most preferably chloride method for preparation of the complexes. or bromide. The number of anionic groups is sufficient In recent years, dinitrogen complexes of certain tran O to satisfy the valence charge on the transition metal. sition metal have been prepared by (1) reacting a coor Due to the high reactivity and instability of the dinitro dination, complex of the transition metal with molecu gen complexes under conditions required for detailed lar nitrogen in the presence of reducing agent, (2) react structural analysis, such complexes are not further char ing a hydride of transition metal in lower oxidation state acterized as to structure. In preferred dinitrogen com with molecular nitrogen or (3) displacing a weaker 15 plexes, it is believed that the ratio of atoms of the transi ligand in a coordination complex of the transition metal tion metal to molecular nitrogen and/or molecular hy with molecular nitrogen. See, for example, Allen, "De drogen is from about 1:0.3 to about 1:3, more preferably velopments in Inorganic Models of N. Fixation,' Bioi from about 1:1 to about 1:3, most preferably about 1:1, norganic Chemistry, Advances in Chemistry Series, 100, and the atomic ratio of transition metal atoms to anionic 79(1971) and Allen et al., Chemical Reviews, 73, 20 groups is from about 1:2 to about 1:4, preferably about 11(1973). Such complexes have been described as useful 1:3. Such complexes are generally soluble in hydrocar in the fixation of nitrogen. See, for example, Van Tam bon solvents and should be maintained under an atmo elen, "Fixation of Molecular Nitrogen under Mild Con sphere of nitrogen, hydrogen or mixture thereof de ditions,” Bioinorganic Chemistry, Advances in Chemis pending upon whether molecular nitrogen, molecular try Series, 100, 95(1971). 25 hydrogen or combination thereof is part of the complex. Heretofore, however, it has not been recognized that For example, a complex having molecular nitrogen and molecular nitrogen or molecular hydrogen will react in no molecular hydrogen is preferably kept under a nitro the absence of a reducing agent with higher oxidation gen atmosphere. state transition metal compound containing no coordi The dinitrogen complex is prepared by reacting, in nate covalent bonds to form a dinitrogen or dihydrogen 30 the absence of a reducing agent, molecular nitrogen or complex of the transition metal. molecular hydrogen in an inert organic diluent with a transition metal compound, preferably a transition SUMMARY OF THE INVENTION metal halide, which compound contains no coordinate The present invention, in one aspect, is a dinitrogen covalent bond. and/or dihydrogen complex of divalent nickel or a 35 Exemplary transition metal compounds include, for transition metal having an oxidation state greater than example, the halides such as the chlorides, bromides, two. In the complex, the transition metal is bonded by a iodides and fluorides, of the transition metals of Groups coordinate covalent bond to molecular nitrogen and/or 4b, 6b, 7b and 8 of Mendeleev's Periodic Table of Ele molecular hydrogen. For purposes of brevity, the fore ments as set forth in Handbook of Chemistry and Physics, going complex will hereinafter be referred to as "the 40 CRC, 48th Edition (1967-1968). Exemplary metals are dinitrogen complex' and will include both the dinitro titanium, chromium, zirconium, tungsten, manganese, gen and dihydrogen complexes as well as mixtures of molybdenum, ruthenium, rhodium, cobalt, nickel and dinitrogen and dihydrogen complexes. platinum, with titanium and zirconium being preferred. In a second aspect, the invention is a method for In the most advantageous embodiments, the transition preparing the aforementioned complex which com 45 metal compound is insoluble in hydrocarbon diluents prises reacting molecular nitrogen, molecular hydrogen and is rendered soluble by the formation of the dinitro or a mixture thereof under moderate conditions of pres gen complex. Exemplary preferred transition metal sure and temperature with a transition metal compound compounds are titanium trichloride, zirconium tetra containing no coordinate covalent bond. With the ex chloride, tungsten hexachloride, molybdenum penta ception of the suitable divalent nickel compounds, the 50 chloride, nickel dichloride, with the halides, particu transition metal compounds used in the method have an larly the chlorides, of titanium being most preferred. oxidation state greater than two. This reaction is advan The reaction to form the complex is advantageously tageously carried out in the absence of a reducing agent. carried out in an inert organic diluent attemperatures in In a third aspect, the invention is a process for poly the range from ambient to about 200 C by pressuring merizing an a-olefin under conditions characteristic of 55 nitrogen or hydrogen gas into a reactor containing the Ziegler polymerization wherein the dinitrogen complex transition metal compound dispersed in the inert dilu is employed as the transition metal component of a ent. For purposes of this invention, an inert organic Ziegler catalyst. diluent is an organic fluid that does not prevent forma In addition to being useful as a polymerization cata tion of the complex and is non-reactive with the com lyst, the dinitrogen complex of the present invention is plex once it is formed. Accordingly, liquid hydrocarbon also useful as a catalyst for alkylation and hydrogena such as the aliphatic and aromatic hydrocarbons are tion reactions and as a catalyst in the fixation of nitro useful diluents with the acyclic aliphatic hydrocarbons gen. being preferred. Examples of suitable inert organic dilu ents include hexane, isooctane, octane, isononane, no DETAILED DESCRIPTION OF THE 65 nane, decane, cyclohexane, benzene, 2,2,5-trimethyl EMBODIMENTS hexane and mixtures thereof. Preferred diluents are The dinitrogen complex of the present invention is mixtures of isoparaffins, especially those having 8 to 9 broadly characterized as a complex comprising a transi carbon atoms per molecule. Pressures employed in the 4,091,082 3 4. reaction normally range from about 40 to about 300 avoid oversaturation of the solvent with polymer. If psig, preferably from about 60 to about 150 psig, with such saturation occurs before the catalyst becomes de nitrogen and/or hydrogen gas constituting at least 10 pleted, the full efficiency of the catalyst is not realized. mole percent, preferably from about 50 to 100 mole For best results, it is preferred that the amount of poly percent, and especially from about 90 to 100 mole per mer in the carrier not exceed about 50 weight percent cent of the gas phase in the reaction vessel. Although based on the total weight of the reaction mixture. concentration of transition metal compound dispersed The organometallic cocatalyst is suitably any reduc in the inert diluent is not particularly critical, it is gener ing component commonly employed in Ziegler poly ally desirable to employ concentrations in the range merization. For example, the cocatalyst may be any from about 0.1 to about 10, preferably from about 1 to O organometallic reducing compounds employed in con 10, weight percent of transition metal compound in the ventional Ziegler polymerization, preferably an alkyl inert diluent. aluminum compound having at least two alkyl groups In cases wherein the transition metal compound is per aluminum, e.g., aluminum trialkyls or dialkyl alumi insoluble in the organic diluent, it is desirable to agitate num halides. Examples include aluminum triethyl, alu the reaction mixture during the reaction to maintain the 15 minum triisobutyl, aluminum tripropyl, aluminum tri insoluble compound dispersed in the diluent.
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