OXIDATIVE ADDITION OF 2,2'-DIPYRIDYL DISULFIDE TO THE CLUSTER [OS3(CO)10(MECN)2]

The cluster [Os3(CO)10(MeCN)2] reacts with 2,2'-dipyridyl disulphide ( 1, pySSpy) to give a range of oxidative addition products which were s eparated by TLC on silica and crystallization: [Os3(pyS)2(CO)10] (2), [Os3(pyS)2(CO)9] (3), [Os2(pyS)2(CO)6] (4) and [Os(pyS)2(CO)2] (5), to gether with some of the hydride [Os3H(pyS)(CO)9] (6), which is not an expected oxidative addition product. The X-ray crystal structures of c ompounds 2, 3, 4 and 6 (compounds 2 and 6 occurring within a single cr ystal), together with the known structure of compound 5, reveal severa l modes of pyS bonding: chelating pyS, mu2-pyS (both sulphur-bonded an d nitrogen, sulphur-bonded) and mu3-pyS.