New cyclic oligomers of dimesitylgermylene carbodiimides (Mes2GeNCN) n (n= 3 (1) and 4 (2)) were synthesized by reactions of dimesityldichlorogermane with either cyanamide in the presence of triethylamine or lithium cyanamide. The reactions always gave 1, the trimer of hypothetical (Mes2Ge N-CN), as the major compound. Higher oligomers 3 (n up to 20-30) also can be isolated depending on the reaction conditions. In THF solution at room ...