Treatment of [(v4-CsHlz)RuH(NH2NMe2)3]PF6 (C8HlZ = cycloocta-1,5-diene) with cyclopentadienylthallium in refluxing acetone affords the novel cyclopentadienyl-ruthenium(I1) complex [ (q5-C5H5)Ru-(v4-CsHlz)H] (1). Reaction of 1 with halogenating agents (CC14, CH2Brz, CH31) in pentane gives the halo complexes [(v5-C5H5)Ru(v4-C8Hl2)X] (2-4; X = C1, Br, I), while halide metathesis on 2 using either NaBr or NaI in methanol provides alternative routes to 3 and 4, respectively. The substitution of the cycloocta-1,5-diene and/or chloro ligands in 2 in a range of solvents and under mild reaction conditions is a rapid and facile process. Mono-and bidentate ligands [CO, PPh3, PMe3, 1,2-bis(diphenylphosphino)ethane, P(OMe)3, PPhzH, MeNC, t-BuNC, 2,6-MezC6H3NC, CN(CH2)6NC, 3,4,7,8-Me4-1,lO-phenanthroline] and the dienes (buta-1,3-diene, 2,3-dimethylbuta-1,3-diene, 1-methyl-4-(methoxycarbonyl)buta-l,3-diene, bicyclo[2.2.l]hepta-2,5-diene) substitute the cycloocta-1,5-diene ligand in 2, in ethanol, acetone, or tetrahydrofuran solutions to give neutral products of the general type [ (v5-C5H5)RuL2C1]. Polyolefins (cyclohepta-173,5-triene, cycloocta-l,3,5-triene, cyclooctatetraene) and aromatics (benzene, hexamethylbenzene, indene, benzyl chloride, triphenylamine) react with 2 in refluxing ethanol solution to give, following anion exchange with NH4PF6, salts of the general formulation [ (v5-C5H5)RuL ]PF& Sodium tetraphenylborate C6H5BPh3)]. Cyclopentadienylsodium reacts with 2 in tetrahydrofuran at room temperature giving ruthenocene, while sodium hydrotris( 1-pyrazoly1)borate (NaHBpz3) with 2 in ethanol yields the unusual "metallocene" [ (v5-C5H5)Ru(HBpz3)]. These compounds are all obtained in high yield and have been characterized by a combination of elemental analysis and spectroscopic methods (IR and 'H and 13C NMR spectroscopy).reacts directly with 2 in refluxing ethanol to give the zwitterionic 7 1 -arene complex [(v5-C5H,)Ru(v6-
