Microwave Promoted Oxidative Addition Reactions of Os3(CO)12: Efficient Syntheses of Triosmium Clusters of the Type Os3(μ-X)2(CO)10 and Os3(μ-H)(μ-OR)(CO)10

Microwave heating allows for the high-yield, one-step synthesis of the known triosmium complexes Os 3 (μ-Br) 2 (CO) 10 ( 1 ), Os 3 (μ-I) 2 (CO) 10 ( 2 ), and Os 3 (μ-H)(μ-OR)(CO) 10 with R = methyl ( 3 ), ethyl ( 4 ), isopropyl ( 5 ), n -butyl ( 6 ), and phenyl ( 7 ). In addition, the new clusters Os 3 (μ-H)(μ-OR)(CO) 10 with R = n -propyl ( 8 ), sec-butyl ( 9 ), isobutyl ( 10 ), and tert-butyl ( 11 ) are synthesized in a microwave reactor. The preparation of these complexes is easily accomplished without the need to first prepare an activated derivative of Os 3 (CO) 12 , and without the need to exclude air from the reaction vessel. The syntheses of complexes 1 and 2 are carried out in less than 15 min by heating stoichiometric mixtures of Os 3 (CO) 12 and the appropriate halogen in cyclohexane. Clusters 3 – 6 and 8 – 10 are prepared by the microwave irradiation of Os 3 (CO) 12 in neat alcohols, while clusters 7 and 11 are prepared from mixtures of Os 3 (CO) 12 , alcohol and 1,2-dichlorobenzene. Structural characterization of clusters 2 , 4 , and 5 was carried out by X-ray crystallographic analysis. High resolution X-ray crystal structures of two other oxidative addition products, Os 3 (CO) 12 I 2 ( 12 ) and Os 3 (μ-H)(μ-O 2 CC 6 H 5 )(CO) 10 ( 13 ), are also presented.