Flash Communication: Different Coordination Modes of the 1,2-Benzisothiazolinate (bit) Ligand at Low-Valent Polyosmium Centers

1,2-Benzisothiazol-3(2H)-one (bitH) reacts with [Os3(CO)10(NCMe)2] to afford triosmium [Os3(CO)10(μ-H)(μ-N,O-bit)] (1) and tetraosmium [{Os2(CO)5(μ-N,O-bit)}2(μ3-N,O,S-bit)2] (2). Oxidative decarbonylation of 1 using Me3NO gives the hexaosmium [Os6(CO)18(μ-H)2(μ3-N,O,S-bit)2] (3). The benzisothiazolinate (bit) ligand displays two different coordination modes (μ-N,O and μ3-N,O,S) at these polyosmium centers, and the μ3-N,O,S coordination mode observed in 2 and 3 is unprecedented.