SYNTHESIS OF 2-(DIPHENYLPHOSPHINO)PHENOLATO AND 2-(DIPHENYLPHOSPHINOMETHYL)-4-METHYLPHENOLATO COMPLEXES OF TITANIUM AND ZIRCONIUM - X-RAY CHARACTERIZATION OF [(ETA(5)-C5H5)(2)ZRCL(OC(6)H(4)PPH(2))] AND [(ETA(5)-C5H5)(2)ZR(OC(6)H(4)PPH(2))(2)]

Complexes [(C5H5)(2)MCl(2)] (M = Ti, Zr) react with the 2-(diphenyl-phosphino)phenol HO(C6H4)PPh(2) in the presence of imidazole to give the corresponding complexes [Cp(2)ZrCl(OC(6)H(4)PPh(2))], 1 and [Cp(2)M(OC(6)H(4)PPh(2))(2)] (2: M = Ti; 3: M = Zr). Under the same experimental conditions, the bulkier ligand 2-(diphenylphosphinomethyl)-4-methylphenol HO(C6H3)-(CH3)CH(2)PPh(2) failed to react with [Cp(2)MCl(2)] (Ti or Zr) but with Cp(2)Zi-(CH3)(2) gives the methyl complex [Cp(2)Zr(CH3){O(C6H3)(CH3)CH(2)PPh(2)}], 4 and [Cp(2)Zr[O(C6H3)(CH3)CH(2)PPh(2)](2)], 5. Compounds 1 and 3 crystallize from CH2Cl2 solution, and their structures have been determined. The relatively short Zr-O bond distance of 1.979(7) Angstrom, and the Zr-O-C bond angle of 160.2(5)degrees, in one phenoxy ligand of 3 suggest significant double bonding between Zr and O atoms. Chemical reduction of 1 with Na/Hg gives the expected cyclic P-metallated Zr-III species [Cp(2)Zr(OC(6)H(4)PPPh(2))] characterized by EPR (g = 1.976; a(P-31) = 14.6 G.). Preliminary data indicate that 3 acts as a diphosphine ligand upon reaction with [{Rh(CO)(2)Cl}(2)].