CONFORMATIONAL-ANALYSIS OF HYDROGEN POLYOXIDES

The semiempirical AM1 method was used for the calculation of conformat ional potential energy surfaces of hydrogen trioxide and tetraoxide. T ile most stable conformation of trioxide is its anti-form, which is ch aracterized by the torsion angle phi = 82.3 degrees, and that of tetra oxide is the anti, anti-form with phi = 80.7 degrees (H-O-O-O) and 74. 1 degrees (O-O-O-O). The structures of the stable conformer; are deter mined by the interaction between lone electron pairs of oxygen atoms. The dipole-dipole interaction of OH groups is weaker than that in hydr ogen peroxide. The results were used for the estimation of the polyoxi de increment of the Benson's additivity scheme, Delta(f)H degrees[O-(O )(2)] = 48+/-6 kJ mol(-1).