Triosmium carbonyl clusters of sulfur and oxygen mixed donor ligands

Abstract

The reaction of the lightly stablized cluster [Os3(CO)10(NCMe)2] with thiosalicylic acid affords two products [{Os3(CO)10(µ-H}]2SC6H4CO2],1 and [Os3H(CO)10SC6,H4C(O)OOs3H(CO)11],2. Complex 2 undergoes CO dissociation to give1 or fragmentation to give [Os3H(CO)10SC6H4 COOH], 3 in solution. Reaction of phthalic acid and [ Os3(CO)10(NCMc)2] gives two products [{Os3(CO)10(µ-H)}2O2CC6H4CO2], 4 and [Os3H(CO)10O2CC6 H4C(O)OOs3H(CO)11], 5. 5 also undergoes CO dissociation to give4, but no such conversion is observed in the preparation of [{Os3(CO)10(µH)}2 (SC6H4S)],6 from the reaction betweeno-dithiobenzene and [Os3(CO)10 (NCMe)2]. Unlike thiosalicylic acid, treatment of [Os3(CO)10(NCMe)2] with 1 equivalent 2,2'-dithiosalicylaldehyde in dichloromethane produces the compounds [Os3(CO)10(SC6H4CHO)2],7 and [Os3(CO)10µ-H)(SC6H4CHO)].8 in moderate yields which are stable in both the solid state and solution. The mechanism for the formation of1-5 is also proposed. All the clusters1-8 have been fully characterized by conventional spectroscopic methods and the structures of1, 3, 4, 7, and8 have been established by X-ray, crystallography.