Trimesitylgermylcarbodiimide lithium, precursor for new mixed polymetallated carbodiimide and polycarbodiimides of Ge, Si, Sb

Trimesitylgermylcarbodiimide lithium characterized in the reaction of trime sitylgermylchloride on dilithium cyanamide, is the starting material to sta ble germylsilyl or unsymetric digermylcarbodiimides. The non hindered Ge-N bond of triethylgermylcarbodiimide is cleaved by t-butyllithium providing a nother route to unsymetric N-triethylgermyl-N'-silylcarbodiimide. Trimesitylgermylcarbodiimide lithium reacts with metal dihalides yielding t rimetalled (Ge, Sb) dicarbodiimides. X-ray structure of his (trimesitylgerm ylcarbodiimido)diethylgermane confirms the inequivalence of the two carbodi imides groups observed by infrared spectroscopy. N-diethylchlorogermyl-N'-trimesitylgermylcarbodiimide with dilithium cyanam ide leads to a tetragermyltricarbodiimide : the bis(N-diethylgermyl-N'-trim esitylgermylcarbodiimido)-carbodiimide, in which inequivalence of the ethyl groups can be explained by the steric hindrance of terminal trimesitylgerm yl carbodiimido groups.