Molybdenum complexes dithiocarboxylates

The reaction between [MoCl4(NCPr)2] and dithiocarboxylic acids is a general route to the preparation of eight-coordinate [Mo(S2CR)4] complexes.168 The crystal structure of [Mo(S2CPh)4] reveals these compounds to be isostructural with the dithiocarbamates, with a dodecahedral coordination around the molybdenum and average Mo—S distances of 2.475(1) and 2.543(1) A to the two different sulfur sites.170 Cyclic voltammetry has shown that in [Mo(acda)4] (Hacda = 2-aminocyclopent-l-ene-l-dithiocarboxylic acid) the Mo can be reversibly oxidized and reversibly reduced in one-electron processes.171... 

The acyl formation reaction is suggested to proceed via initial attack at the carbyne carbon, but evidence is not conclusive. Reaction of the analogous Cp complexes with cyclohexene sulfide provides exclusively the dithiocarboxylate derivatives. Presumably the second sulfur addition is considerably more rapid than for the Tp complexes due to lowered steric crowding around the molybdenum... 

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