Systematic Synthesis of Hexanuclear Phosphido-bridged Osmium Clusters; Crystal and Molecular Structure of HOs6(CO)22PH2

The phosphido-bridged cluster [Os6(µ-H)(CO)22(µ-PH2)] and the corresponding phosphinidene-bridged cluster [Os6(µ-H)2(CO)21(µ-PH)] have been prepared from the reaction of [Os3(CO)11(PH3)] with [Os3(CO)11(NCMe)] in toluene. In a similar reaction, [Os6(µ-H)(CO)21(NCMe)(µ-PH2)] has been prepared from the reaction of [Os3(CO)11(PH3)] with [Os3(CO)10(NCMe)2]. The two Os6 clusters have been fully characterized on the basis of their spectroscopic data and, in the case of [Os6(µ-H)(CO)22(µ-PH2)], by single-crystal X-ray analysis. In both compounds, two Os3 triangles are linked by a PH2 group which is terminally bound to each triangle. Thermolysis of [Os6(µ-H)(CO)22(µ-PH2)] and [Os6(µ-H)(CO)21(NCMe)(µ-PH2)] leads to the formation of [Os6(µ6-P)(CO)18]– and [Os6(µ-H)(µ6-P)(CO)18], respectively.