Synthesis and Characterization of Osmium-Containing Silsesquioxanes: High-Yield Routes to {Os3(CO)10(mu-H)[(mu-O)Si7O10(c-C6H11)7]} and the New Clusters {Os3(CO)10(mu-H)[(mu-O)Si7O9(OH)2(c-C6H11)7]}, {[Os3(CO)10(mu-H)]2(mu-O)2Si7O9(OH)(c-C6H11)7}, {Os3(CO)10(mu-H)[(mu-O)Si8O11(OH)(c-C6H11)8]}, and {[Os3(CO)10(mu-H)]2(mu-O)2Si8O11(c-C6H11)8}

The reactions of [Os3(CO)10(mu-H)(mu-OH)] (3) with the incompletely condensed silsesquioxanes [(c- C6H11)7Si7O9(OH)3] (1) and [(c-C6H11)8Si8O11(OH)2] (2) afford in high yield {Os3(CO)10(mu-H)[(mu-O)- Si7O10(c-C6H11)7]} (4) and the new compounds {Os3(CO)10(mu-H)[(mu-O)Si7O9(OH)2(c-C6H11)7]} (5), {[Os3(CO)10(mu-H)]2(mu-O)2Si7O9(OH)(c-C6H11)7} (6), {Os3(CO)10(mu-H)[(mu-O)Si8O11(OH)(c-C6H11)8]} (8), and {[Os3(CO)10(mu-H)]2(mu-O)2Si8O11(c-C6H11)8} (9), which are discrete molecular models of silica-anchored [Os3(CO)10(mu-H)(mu-OSi)]. Compounds 6 and 9 represent the first examples of complexes containing two [Os3(CO)10(mu-H)] cluster cores. The X-ray structures of 5, 8, and 9 are reported.