The syntheses of novel sulfur centred spirocyclic cluster complexes starting from [Re2(μ-H)(μ-SH)(CO)8]

Abstract

[Re₂(μ-H)(μ-SH)(CO)₈] 1 reacted with [Re₂(CO)₈(MeCN)₂], [Os₃(CO)₁₁(MeCN)], [Co₂(CO)₈] and [Fe₂(CO)₉], respectively, by SH oxidative addition to give the spirocyclic cluster complexes [{Re₂(μ-H)(CO)₈}₂(μ₄-S)] 2, [(OC)₈(μ-H)Re₂(μ₄-S)Os₃(μ-H)(CO)₁₀] 3, [(OC)₈(μ-H)Re₂(μ₄-S)Fe₂(CO)₆(μ₄-S)Re₂(μ-H)(CO)₈] 4 and [(OC)₈(μ-H)Re₂(μ₄-S)Co₂(CO)₆(μ₄-S)Re₂(μ-H)(CO)₈] 5 in good yields. Complexes 2, 3 and 4 have been characterised by crystal structure analysis. Cluster complex 2 consists of two hydrido bridged dirhenium octacarbonyl units linked by a tetrahedral μ₄-S. The crystal structure of 3 shows an analogous Re₂ unit and a planar Os₃ ring linked by a tetrahedral μ₄-S. Cluster complex 4 consists of one Fe₂ and two Re₂ units linked into a chain by two tetrahedral μ₄-S bridges. The structure of 5 is similar to that of 4 and was derived from spectroscopic data and elemental analysis. The formation of 3 was shown to proceed in two steps. First the acetonitrile ligand in [Os₃(CO)₁₁(MeCN)] is substituted by 1 followed by SH oxidative addition giving the intermediate [(OC)₈(μ-H)Re₂(μ₃-S)Os₃(μ-H)(CO)₁₁] 6. Upon heating the cluster complex eliminates one equivalent of CO yielding 3 as the final product. The molecular structure of 6 has been established by single crystal X-ray analysis.