UNUSUAL BONDING IN THE 1,1,1-TRIAMINO-2,2,2-TRICYANOETHANE MOLECULE

Ab initio electronic structure calculations, carried out at the HF/6-31G* level, reveal existence of two isomers of the 1,1,1-triamino-2,2,2-tricyanoethane molecule. The less stable isomer has the structure of a hexasubstituted ethane with a covalent single bond between the central carbon atoms. The second isomer is best described as a triaminocarbenium (guanidinium) tricyanomethanide (cyanoformide). The bonding in the ionic isomer is of a complicated nature. Analysis of the critical points in the electron density uncovers, in addition to a central carbon-carbon bond and the expected bonds within the guanidinium and cyanoformide moieties, a pattern of three identical bonds between the nitrogen atoms of the amino and cyano groups, and three ring points. © 1990.