Synthesis, Structures, and Reactivity of Ruthenium(II) Nitrosyl Tri- and Dialkyl Complexes

Treatment of Ru(dtbpy)(NO)Cl3 (dtbpy = 4,4′-di-tert-butyl-2,2′-bipyridyl) (1) with Me3SiCH2MgCl afforded the trialkyl compound mer-Ru(dtbpy)(NO)(CH2SiMe3)3 (2), which exhibits νNO at 1741 cm−1 in the IR spectrum. The solid-state structure of 2 shows a mer arrangement for the three alkyl groups and that the nitrosyl is trans to dtbpy. Protonation of 2 with HX afforded the dialkyl compounds cis,cis-Ru(dtbpy)(CH2SiMe3)(NO)X (X = Cl (3), OTs (4)), in which X is trans to an alkyl group. Treatment of 3 with AgOTf (OTf− = triflate) afforded cis,cis-Ru(dtbpy)(CH2SiMe3)2(NO)(OTf) (5), which reacted with amines RNH2 to give the adducts cis,cis-[Ru(dtbpy)(CH2SiMe3)2(NO)(NH2R)][OTf] (R = meistyl (6), 4-tol (7)). Substitution of 5 with NaOR led to the isolation of cis,trans-Ru(dtbpy)(CH2SiMe3)2(NO)(OR) (R = Ph (8), SiMe3 (9), SiPh3 (10)), in which the nitrosyl is trans to OR−, whereas that with NaSR gave cis,cis-Ru(dtbpy)(CH2SiMe3)2(NO)(SR) (R = 2,6-Me2C6H4 (11), SiPh3 (12)). Treatment of 5 with K[OsO3N] afforded the bimetallic complex cis,cis-Ru(dtbpy)(CH2SiMe3)2(NO)(NOsO3) (13), containing an unsymmetrical Os(VIII)N−Ru(II) bridge. The crystal structures of 2−5, 7−10, 12, and 13 have been determined.