Abstract: | The potential energy hypersurface of the conversion of aminophosphaethyne ( 1 ) to 1-aza-3-phosphaallene ( 2 ) has been studied with the MNDO method. The interconversion includes five intermediate species. The structure and energy of 1 and its isomers produced by a hydrogen shift have been calculated also with ab initio molecular orbital theory by a split valence basis set including a polarization function at the P atom. The results reveal that all the isomers are equilibrium structures. The ab initio calculation predicts the carbenaazaphosphirane 3 to be the intermediate lowest in energy. It is suggested that a carbene ( 3 ), phosphinidene ( 4 ) or azaphosphirene ( 5 ) are responsible for the 1-aza-2,4-diphosphole formation. |