Alkynethiolato and alkyneselenolato ruthenium half-sandwich complexes: synthesis, structures, and reactions with (eta(5)-C(5)H(5))(2)Zr

Abstract

Alkynethiolato and alkyneselenolato complexes of ruthenium, CpRu(PPh(3))(2)(EC(triple bond)CR) (Cp = eta(5)-C(5)H(5); E = S, R = Ph (1a), SiMe(3) (1b), (t)Bu (1c); E = Se, R = Ph (2a), SiMe(3) (2b)), were synthesized by the reactions of CpRuCl(PPh(3))(2) with corresponding lithium alkynechalcogenolates in THF. An analogous reaction of Cp*RuCl(PEt(3))(2) (Cp* = eta(5)-C(5)Me(5)) with LiSC(triple bond)CPh produced Cp*Ru(PEt(3))(2)(SC(triple bond)CPh) (3). Complexes 1a and 2a were allowed to react in THF with "Cp(2)Zr", generated in situ from Cp(2)ZrCl(2) and 2 equiv of n-BuLi, from which the S-bridged Ru-Zr dinuclear complexes CpRu(PPh(3))(C(triple bond)CPh)(mu-S)ZrCp(2) (4a) and CpRu(PPh(3))(C(triple bond)CPh)(mu-Se)ZrCp(2) (4b) were isolated, respectively. In these complexes, C-S(Se) bond cleavage of the alkynechalcogenolate ligands was promoted by "Cp(2)Zr", and the Zr atom was oxidized from II to IV. Treatment of 4a and 4b in THF under 1 atm CO gave rise to CpRu(CO)(C(triple bond)CPh)(mu-E)ZrCp(2) (E = S (5a), Se (5b)), while addition of tert-butyl isocyanide to a THF solution of 4b afforded CpRu(CN(t)()Bu)(C(triple bond)CPh)(mu-Se)ZrCp(2) (6). The crystal structures of 1a, 1c, 2a, 2b, 3, 4a, 4b, and 5b were determined by X-ray diffraction analysis.