Mono(maleonitriledithiolene)molybdenum(IV) and Bis( μ ‐sulfido)‐Bridged Dimolybdenum(V) Complexes with MoS Moiety

Mono(maleonitriledithiolene)sulfidomolybdenum(IV) complex, [MoS(S 4 )(mnt)] 2− ( 2 ; mnt=maleonitriledithiolene) was synthesized by the substitution reaction of a tetrasulfido ligand of the known [MoS(S 4 ) 2 ] 2− ( 1 ) upon reaction with one or even excess equivalent of Na 2 (mnt) in aqueous MeCN solution in air. Surprisingly, 2 undergoes dimerization on treatment with alkyl halide such as MeI and PhCH 2 Br to form bis( μ ‐sulfido)dimolybdenum(V) species, [{MoS(mnt)} 2 ( μ ‐S) 2 ] 2− ( 3 ). These complexes have been characterized by IR, UV/VIS spectroscopy, cyclic voltammetry, elemental analysis, and by X‐ray crystal‐structure analysis. Differences in the relative stability and electrochemical behavior of 1, 2 , and 3 have been correlated with theoretical calculations at DFT level.