The preparation of mixed ligand ruthenocenes containing bulky cyclopentadienyl ligands.: Crystal structures of pentaphenylruthenocene, [Ru(η5-C5Ph5)(η5-C5H5)], pentaparatolylruthenocene, [Ru{η5-C5(p-MeC6H4)5}(η5-C5H5)] and pentaphenylpentamethylruthenocene, [Ru(η5-C5Ph5)(η5-C5Me5)]

The preparations of the mixed ligand ruthenocenes [Ru(eta(5)-C5R5)(eta(5)-C5H5)] [R-5=Ph-5 (1), Ph4H (2) and (p-MeC6H5)(5) (3)] and [Ru(eta(5)-C5Ph5)(eta(5)-C5Me5)] (4) are reported. The molecular structures of 1 (Pbca, a=14.234(3), b=20.276(3), c=20.625(4) Angstrom), 3 (P (1) over bar, a=19.319(7), b=21.007(7), c=10.436(3) Angstrom, alpha=103.76, beta=95.07(3), gamma=112.59(2)degrees) and 4 . H2O (P (1) over bar, a=12.145(2), b=12.696(4), c=14.281(2) Angstrom, alpha=80.41(2), beta=66.43(1), gamma=62.80(2)degrees) were determined by single crystal X-ray diffraction studies; the cyclopentadienyl rings in each structure are almost parallel and nearly eclipsed. For 1, 2 and 3, two oxidative processes, but no reductive electrochemical processes, were observed. The precipitated product from the reaction of Ru-3(CO)(12), C5Ph5Br and Zn in xylenes yielded, after subsequent reaction with NaBPh4, [Ru(eta(5)-C5Ph5){eta(6)-C6H4(CH3)(2)}](+) BPh4- (5). (C) 1998 Elsevier Science S.A. All rights reserved.