Binuclear oxidative addition of Sb–Cl
bonds with the clusters
Os<sub>3</sub>(CO)<sub>11</sub>(NCCH<sub>3</sub>), <b>1</b>,
or Os<sub>3</sub>(CO)<sub>10</sub>(NCCH<sub>3</sub>)<sub>2</sub>, <b>2</b>, was found to be an effective synthetic route to organometallic
clusters and rings containing μ<sub>2</sub>-SbPh<sub>2</sub> or μ<sub>3</sub>-SbPh moieties. Thus, the reaction of SbPh<sub>2</sub>Cl with <b>1</b> afforded the tetranuclear ring Os<sub>3</sub>(CO)<sub>11</sub>(Cl)(μ-SbPh<sub>2</sub>), <b>3</b>, while its reaction with <b>2</b> afforded the pentanuclear
ring Os<sub>3</sub>(CO)<sub>10</sub>(Cl)<sub>2</sub>(μ-SbPh<sub>2</sub>)<sub>2</sub>, <b>6</b>. In each case, two or three
isomeric products were isolated depending on the reaction conditions.
The analogous reaction of SbPhCl<sub>2</sub> with <b>1</b>,
on the other hand, afforded the spiked triangular cluster Os<sub>3</sub>(CO)<sub>11</sub>(Cl)<sub>2</sub>(μ<sub>3</sub>-SbPh), <b>7</b>, which also existed as two isomers. Pathways for these reactions
have been proposed, and the experimental and computational evidence
presented.