The reactions of methylgermanes with [µ4-Ge{Co2(CO)7}2]: extending the chain of linked GeCo2 triangles
Abstract
Methylgermanes GeMeRH2(R = H or Me) react with [µ4-Ge{Co2(CO)7}2]1 to form [µ4-Ge{Co2(CO)7}{Co2(µ-GeMeR)(CO)6}](R = H 2a or Me 2b) and [µ4-Ge{Co2(µ-GeMeR)(CO)6}2](R = H 3a or Me 3b), depending on reaction ratio and time. An alternative synthesis of 2a is from GeMeH3 and [µ4-Ge{Co(CO)4}Co3(CO)9]. Corresponding reactions of 1 with silanes or stannanes do not give compounds of type 2 or 3, while the silicon analogue of 1 undergoes fragmentation with germanes, rather than cluster extension. 13CO-Exchange, CO-addition, and thermolysis reactions of 1, 2 and 3 are compared. An X-ray structure analysis of 3b[triclinic, space group P, a= 9.607(3), b= 14.796(4), c= 9.476(3)Å, α= 95.83(2), β= 91.94(2), γ= 98.83(2)°, R= 0.044, for 3353 data with I > 2σ(I)] confirms the extended core of four GeCo2 triangles linked through the Ge apices and the Co–Co edges.