Formation and reactions of mono- and di-substituted derivatives of [µ<sub>4</sub>-Ge{CO<sub>2</sub>(CO)<sub>7</sub>}<sub>2</sub>], containing functional µ-GeRH or µ-GeRCl groups
作者:Siew Kim Lee、Kenneth M. Mackay、Brian K. Nicholson
DOI:10.1039/dt9930000715
日期:——
The reaction of [mu4-GeCo2(CO)7}2] 1 with GeRH3 (R = Et or Ph) has been found to give [mu4-GeCo2(CO)7}Co2(CO)6(mu-GeRH)}] 2 or [mu4-GeCo2(CO)6(mu-GeRH)}2] 3 depending on the stoichiometries and conditions. Analogues of 2 or 3 with mu-GeMeCl groups form from 1 and GeMe(Cl)H2. Reaction of 2 with [Co2(CO)8] gives an open cluster with a mu-Ge(R)Co(CO)4 group which readily condenses to a closo-cluster with a Ge2Co4 core. Analogous reactions of 3 with [Co2(CO)8] ultimately give clusters [Co4(mu4-GeR)2mu-GeCo2(CO)7}(CO)10] again via more-open intermediates. Corresponding species are obtained from the mu-GeMeCl compounds and [Co(CO)4]-. An X-ray structure analysis of [Co4(mu4-GeEt)2mu-GeCo2(CO)7}(CO)10] has been performed: triclinic, space group P1BAR, a = 10.617(1), b = 16.895(3), c = 9.822(4) angstrom, alpha = 104.22(2), beta = 94.40(2), gamma = 102.03(1)-degrees, Z = 2, R = 0.027, for 3516 data with I > 2sigma(I). It reveals a structure consisting of a pseudo-octahedral Ge2Co4 unit, with one of the Co-Co bonds edge-bridged by a mu-GeCo2(CO)7 moiety.