On the reactivity of complexes [Ni(NHC)2] with CS2

Abstract

A study of the reaction of [Ni(NHC)₂] synthons with the heterocumulene CS₂ is reported. Nickel complexes of η²-(C–S) side-on coordinated CS₂, [Ni(NHC)₂(η²-CS₂)] (NHC = IiPr^Me (1a), IiPr (1b)) were obtained from the reaction of CS₂ with precursors of [Ni(NHC)₂] (NHC = IiPr^Me, IiPr). The result of this reaction critically depends on the NHC employed, as [Ni(IMes)₂], the complex of the sterically more demanding N-aryl substituted NHC IMes, led to formation of the dinuclear complex [{Ni(IMes)(μ²-CS₂)}₂] (2d). The related compound [{Ni(IDipp)(μ²-CS₂)}₂] (2c) was isolated from the reaction of [Ni(IDipp)(η⁶-C₇H₈)] with CS₂. If [Ni(cAAC^Me)₂] was used, insertion of CS₂ into the cAAC carbon nickel bonds occurs and the bis-(azolium-2-dithiocarboxylate) complex [Ni(cAAC^Me-CS₂)₂] (3e) was formed.