The monomeric ruthenium(II) complexes [(η6-C6H5XCH2PtBu2-κ-P)RuCl2] 3, 4 were prepared either on a reductive route from RuCl3·3H2O and tBu2PCH2XPh (X = CH2
1, OCH2
2) or by ligand replacement reactions from [(p-cym)RuCl2]2 and the phosphine via the p-cymene compounds [(p-cym)(C6H5XCH2PtBu2-κ-P)RuCl2] 6, 7 as intermediates. Abstraction of one chloro ligand from 3
with AgPF6 led to the formation of the dinuclear complex [{(η6-C6H5CH2CH2PtBu2-κ-P)RuCl}2](PF6)2
8, which reacts with acetone, CH3CN and PMe3 by bridge cleavage to afford the mononuclear compounds [(η6-C6H5CH2CH2PtBu2-κ-P)RuCl(L)]PF6
9, 10, 12. Both 10 and 11 (the latter containing 2 as chelating ligand) were also obtained from 3, 4
and AgPF6 in the presence of acetonitrile. Hydridoruthenium(II) complexes [(η6-C6H5XCH2PtBu2-κ-P)RuHCl] 13, 14, [RuHCl(H2)(L)2] 15 (L =
1), 16 (L =
2) and [RuHCl(CO)(2)2] 17 could be prepared from RuCl3·3H2O and 1 or 2 in the presence of NEt3 under reductive conditions. Insertion, substitution and addition reactions of compound 17 led to the
formation of [Ru(CHCH2)Cl(CO)(2)2] 18, [RuHF(CO)(2)2] 19, and [RuHCl(CO)2(2)2] 20, respectively. The cationic allenylidene complexes [(η6-C6H5XCH2PtBu2-κ-P)RuCl(CCCPh2)]A 22a,b (X = CH2; A = BF4, PF6) and 23 (X = OCH2; A = PF6) were prepared from 3, 4 or 13, HCCC(OH)Ph2
and either one equiv. of AgPF6 or an equivalent amount of HBF4 in diethyl ether. Treatment of 15 and 16 with acetylene afforded the five-coordinate vinylideneruthenium(II) compounds [RuHCl(CCH2)(L)2] 24, 25 which in the presence of HBF4 are highly efficient catalysts for the Ring Opening Metathesis Polymerization (ROMP) of cyclooctene. The molecular structures of 10 and 17 were determined crystallographically.