Theoretical study on tetrazole and its derivatives (3) MP2 and thermodynamic calculations of amino derivatives of tetrazole

Fully optimized geometries and electronic structures of amino derivatives c s tetrazole are obtained at MP2/6-31G* level. The tetrazole rings are plana r and aromatic for all the amino derivatives of tetrazole. The amino group is not co-planar with the ring and its conformation is mainly determined by the lone pair electronic repulsion between the substituent and the ring. N (4) atom is more negatively charged and is the meet probable coordination s ite. The energy gaps between LUMOs and HOMOs of 2H-aminotetrazoles and C-am inotetrazole neutrals are smaller than those of the corresponding 1H-isomer s and N-aminotetrazole neutrals respectively. The IR frequencies, thermodyn amic properties and temperature-dependent functions for heat capacities in the form (a + bT + cT(2)) in the 300-1000K range are reported.