Substitution reactions of [Ge2Co4Fe2(CO)21] with methylgermanes, and its decarbonylation. Structures of [Fe2{µ4-GeCo2(CO)6(µ-GeMe2)}2(CO)7] and [Fe3{µ3-GeCo(CO)4}2(CO)9]
Abstract
The compound GeMe2H2 reacted with [Fe2{µ4-Ge[Co2(CO)7]}2(CO)7], to replace only the µ-CO on the Co–Co bonds, forming [Fe2{µ4-Ge[Co2(CO)6(µ-GeMe2)]}2(CO)7]. The monosubstituted product [Fe2{µ4-Ge[Co2(CO)7]}{µ4-Ge[Co2(CO)6(µ-GeMe2)]}(CO)7] and similar products from GeMeH3 are also indicated. A crystal structure analysis of [Fe2{µ4-Ge[Co2(CO)6(µ-GeMe2)]}2(CO)7] confirmed an extended core of six GeM2 triangles, linked through the germanium apices and the Co–Co or Fe–Fe edges. Heating [Fe2{µ4-Ge[Co2(CO)7]}2(CO)7] at 50–60 °C for 4–7 weeks yielded as major product [Fe2Co4Ge2(CO)n](n= 19 or 20) whose spectroscopic properties indicate a square-bipyramidal cluster with a Fe2Co2Ge2 core. The minor product was the crystallographically characterised closo-trigonal-bipyramidal cluster [Fe3{µ3-GeCo(CO)4}2-(CO)9] with a Ge2Fe3 core.