Homoleptic selenium cyanides: attempted preparation of Se(CN)4 and redetermination of the crystal structure of Se(CN)2.

The preparation of Se(CN) 4 was attempted by the reaction of SeF 4 with Me 3SiCN at low temperatures. However, selenium tetracyanide could not be detected by NMR spectroscopy; instead, the decomposition product Se(CN) 2 was isolated and its crystal structure was redetermined. In the structure of Se(CN) 2, layers are present with secondary Se...N interactions. The structure of Se(CN) 4 and its reductive decomposition reaction has been calculated at the MP2 level of theory.