Cluster chemistry: XXXVIII. Reactions between M(C 2R)(PR′ 3 (M = Cu, Ag, Au; R = Ph, C 6F 5; R′ = Me Ph) and H 2Os 3(CO) 10: X-ray structures of Os 3Au(μ-CHCHR)(CO) 10(PPh 3) (R = Ph and C 6F 5)

Abstract

The reactions of Os 3(μ-H) 2(CO) 10 with a series of Group IB metal acetylide-tertiary phosphine complexes are described. Whereas the compounds M(C 2C 6F 5)(PPh 3) (M = Cu, Ag, Au) afforded the complexes MOs 3(μ-CHCHC 6F 5)(CO) 10(PPh 3) cleanly and in high yield, complex mixtures of products were obtained from reactions of the analogous phenylacetylides. The complexes MOs 3(μ-CHCHPh)(CO) 10(PPh 3), MOs 3(μ-CHCHPh)(CO) 9(PPh 3) 2 and MOs 3(μ-H)(CO) 10(PPh 3) (of known structure), and MOs 3(μ-CHCHPh)(CO) 9(PPh 3) 2 and HMOs 3(CHCPh)(CO) 8 (of unknown structure) were characterised; Au(C 2Ph)(PMe 3) afforded similar derivatives. The reactions proceed by oxidative-addition and hydrogen migration steps; MP bond cleavage reactions also occur to a small extent. The molecular structures of AuOs 3(μ-CHCHC 6R 5)(CO) 10(PPh 3) (R = F or H) were determined by X-ray analyses. For R = F, crystals are triclinic, space group P 1 with a 9.081(2), b 13.291(2), c 17.419(2) Å, α 84.49(1), β 76.20(2), γ 75.81(2)° and Z = 2; 4622 observed data [ I > 2.5σ( I)] were refined to R = 0.027, R W = 0.031. For R = H, crystals are triclinic, space group P 1 , with a 9.403(4), b 13.448(3), c 13.774(4) Å, α 83.34(2), β 88.66(3), γ 70.21(3)°, and Z = 2; 4405 observed data [ I > 2.5σ( I)] were refined to R = 0.030, R W = 0.033. The two molecules differ in the orientation of the Ph rings of the PPh 3 groups, but are otherwise similar to Os 3(μ-H)(μ-CHCHBu t)(CO) 10 with the μ-H ligand replaced by the isolobal μ-Au(PPh 3) group.