SYNTHESES AND CHARACTERIZATION OF NICKEL(II) AND RUTHENIUM(II) COMPLEXES WITH THE NOVEL PHOSPHINE-LIGANDS YLPHOSPHINO)METHYL)-1-PHENYL-1-SILACYCLOPENT-3-ENE AND 1,1-BIS ((DIPHENYLPHOSPHINO)METHYL)-1-SILACYCLOPENT-3-EN - CRYSTAL-STRUCTURE OF CPRUCL[(PPH2CH2)(2)(SIC4H6)]

The reaction of the lithium salt of chlorodiphenylphosphine with 1-chl oro-1-phenylsilacyclopent-3-ene (1) and 1, 1-dichlorosilacyclopent-3-e ne (2) gave good yields of ylphosphino)methyl)-1-phenyl-1-silacyclopen t-3-ene (L) (3) and ((diphenylphosphino)-methyl)-1-silacyclopent-3-ene (L') (4), Both molecules were obtained as white solids characterized by NMR. Red and red-violet diamagnetic square-planar complexes trans-N iCl2L2 and cis-NiCl2L' were obtained by reacting NiCl2. 6H(2)O with 3 and 4, respectively. Substitution of two PPh3 in CpRuCl(PPh3)(2) by 4 gave CpRuCl(L') (7) in good yield. Orange crystals of 7 contain monome ric pseudooctahedral ruthenium(II) centers surrounded by a Cl atom, a Cp ligand, and the two phosphorus atoms of the s((diphenylphosphino)me thyl)-1-silacyclopent-3-ene ligand, The silacyclopentene ring adopts a puckered ground state configuration with a puckering angle of 10 degr ees, 7 can be described as a spirannic compound with roughly perpendic ular Ru-P(1)-C(10)-Si-C(20)-P(2) and Si-C(6)-C(7)-C(8)-C(9) rings.