Structural characterization of the sulfur-capped triangulo cluster, Cp2W2Fe(CO)7(S)

Abstract

Cp2W2(CO)4(W[triple bond]) reacts with Fe2(CO)6([mu]-S2) to give Cp2W2Fe(CO)7([mu]3-S) (1) (10%) and Cp2W2Fe2(CO)8([mu]3-S)2 (5%). Spectral properties, cyclic voltammetry, and the structure of 1 are reported. Cluster 1 is a triangulo cluster [CpW(CO)2]2(Fe(CO)3)([mu]3-S), with bond lengths: W-W 3.036(1) A, W-Fe 2.80(2) (avg.) W-S 2.36(1) A, and Fe-S 2.204(7) A. Crystallographic data: a, b, c 16.212(4), 12.657(6), 20.236(8) A; [beta] 113.25(3)[deg]; V 3815(2) A3; Z = 8; [varrho]c 2.72 g/cm3; R1 = 0.070; R2 = 0.10 on 4060 reflections. A qualitative EHMO scheme is used to rationalize the lack of contraction of the metal-metal bonds which is usually observed when such bonds support bridging sulfide ligands.