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 SeF4 with Me3SiCN 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 center dot center dot center dot N interactions. The structure of Se(CN)(4) and its reductive decomposition reaction has been calculated at the MP2 level of theory.