The formation, structure, and reversible carbonylation of [(η5-C5H5)MM′(CO)7(SR)] complexes; reactions of [(η5-C5H5)MM′(CO)8(SR)] with hexafluorobut-2-yne

Abstract

The action of heat on [(η⁵-C₅H₅)(OC)₃M(µ-SR)M′(CO)₅](1)(M or M′= Cr, Mo, or W; R = Me or Ph) gives [(η⁵-C₅H₅)(OC)₂[graphic omitted](CO)₅](2) containing a metal–metal bond. Photolysis of (2) in the presence of carbon monoxide regenerates (1) in an example of reversible cleavage of a M–M bond by carbon monoxide. The octacarbonyls (1) react with hexafluorobut-2-yne to give products of substitution at the (η⁵-C₅H₆) M group. The spectroscopic parameters of the complexes and crystal-structure analyses of (1a; M = M′= W, R = Me), (2b; M = Mo, M′= W, R = Me), and [(η⁵-C₅H₅)(OC)(CF₃C₂CF₃)W(µ-SMe)W(CO)₅](5) are discussed in terms of the electronic properties of the bridging thiolato-group and the metal centres.