New synthetic strategies for organometallic complexes with thiolate ligands

Article abstract of DOI:10.1021/om00135a014

Reactions between several carbonylmetalate anions (PPN[Mn(CO)₅] and PPN[M(CO)₃(η-C₅H₅)]; PPN⁺ = Ph₃PNPPh₃⁺; M = Mo, W) and organic disulfides (RSSR; R = Ph, Me, CF₃) initially give the metal thiolate complexes Mn(SR)(CO)₅ and M(SR)(CO)₃(η-C₅H₅). The tungsten species are stable and isolable. The molybdenum and manganese compounds are not stable; the former rapidly lose CO and form thiolate bridge dimers (a known reaction) while the later is converted, within this reaction system, to a mixture of Mn₂(μ-SR)₂(CO)₈ and PPN[Mn₂(μ-SR)₃(CO)₆]. Reactions between these carbonylmetalate anions and [Me₂SSMe]BF₄ yield the same mononuclear metal thiolate complexes which, when appropriate, lose CO and dimerize. If an excess of this sulfonium reagent is present, a further reaction may also occur to produce unstable complexes with monodentate organic disulfide ligands ([Mn(CO)₅(RSSR)]⁺ and [M(RSSR)-(CO)₃(η-C₅H₅)]⁺). The reaction of PPN[W(CO)₃(η-C₅H₅)] with [W(MeSSMe)(CO)₃(η-C₅H₅)]BF₄ gives W(SMe)(CO)₃(η-C₅H₅). This reaction is much faster than the reaction of PPN[W(CO)₃(η-C₅H₅)] with MeSSMe, indicating that coordination of the disulfide to the metal has substantially enhanced its reactivity toward nucleophilic attack.