Molybdenum complexes thionitrosyl

The first thionitrosyl complex was discovered by chance during an attempted synthesis of molybdenum nitrido complexes in the presence of a source of sulfur, tetrathiuram sulfide.168 This work of Dilworth and Chatt was reported in 1974 and ultimately led to the syntheses of a range of Mo, Re and Os thionitrosyl complexes starting with the respective nitrido complexes.143,164 Nitrosyl complexes, like carbonyls, had been known for decades, and the more recent syntheses of thio-carbonyl complexes forebode the advent of thionitrosyl complexes. However, convenient synthetic routes based on analogies with syntheses of NO complexes were generally not available because the requisite precursors did not exist or were inconvenient to handle. Sulfiliminato complexes (M=N=SR2) of transition metals are as yet unknown. The chemistry of thionitrosyl complexes was the subject of a recent review.179... 

The related molybdenum thionitrosyl complex [Mo(NS)(S2CNEt2)3] has also been prepared in low yield as a result of a dithiocarbamate fragmentation process, after reaction of [Mo(N-p-tol)2Cl2(dme)] with 2 equiv of NH4S2CNEt2 (442). The precise nature of this process remains unknown, but the thionitrosyl ligand formally results from extrusion of the backbone carbon atom. 

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