Tungsten Ligand-Based Sulfur-Atom-Transfer Catalysts: Synthesis, Characterization, Sustained Anaerobic Catalysis, and Mode of Aerial Deactivation.

The synthesis, properties, X-ray structures, and catalytic sulfur-atom-transfer (SAT) reactions of W(μ-S)(μ-S)(dtc)(dped) [; dtc = SCNR, where R = Me, Et, Bu, and Bn; dped = SCPh] and W(μ-S)(dtc)(dped) () are reported. These complexes represent the oxidized () and reduced () forms of anaerobic SAT catalysts operating through the bidirectional, ligand-based half-reaction (μ-S)(μ-S) ↔ (μ-S) + S. The catalysts are deactivated in air through the formation of catalytically inactive oxo complexes, (dtc)WO(μ-S)(μ-dped)W(dtc)(dped) (), prompting us to recommend that group 6 SAT activity be assessed under strictly anaerobic conditions.