RELATIVE STABILITIES OF THE ASYMMETRIC OPOP, SYMMETRICAL OPPO AND CYCLIC CONFORMATIONS OF P2O2

Various P2O2 planar isomers are investigated by molecular orbital calculations. Cyclic OPOP (1A(g)) is predicted to be more stable than OPOP (3A"-cis) and OPPO (1A(g)-trans) by 5.6 and 23.1 kcal/mol, respectively. The dimerization energy of 2PO --> cyclic OPOP lies around 55 kcal/mol; the asymmetrical conformations OPOP and symmetrical OPPO are also bound. The computed vibrational frequencies and corresponding absorption intensities (derived at the SCF level) should help future experimental characterizations of these P2O2 isomers.