The IRC path on the hypersurface of the title reaction of H(1)CH(2)=NH (I), to give :C=NH, is found and the ab initio (4-31G) calcns. of the change in quantum topolog. properties (e.g., the characteristics and strengths of bonds, electronic populations of atoms, etc.) provide a quant. description of the H(1)-C bond cleavage, the formation and departure of H(1)-H(2) from I. The title reaction is cooperative but not synchronous.

Key words: QUANTUM CHEMISTRY, CHEMICAL BONDS, ELECTRON DENSITY, AB INITIO CALCULATION, MATRICES, TOPOLOGY, IMINE, METHANAMINE