THE PREPARATION OF MIXED-LIGAND RUTHENOCENES CONTAINING BULKY CYCLOPENTADIENYL LIGANDS - CRYSTAL-STRUCTURES OF PENTAPHENYLRUTHENOCENE, [RU(ETA(5)-C5PH5)(ETA(5)-C5H5)], PENTAPARATOLYLRUTHENOCENE, [RU(ETA(5)-C-5(P-MEC6H4)(5))(ETA(5)-C5H5)] AND PENTAPHENYLPENTAMETHYLRUTHENOCENE, [RU(ETA(5)-C5PH5)(ETA(5)-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) ov er 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 pro cesses, but no reductive electrochemical processes, were observed. The precipitated product from the reaction of Ru-3(CO)(12), C5Ph5Br and Z n 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.