Structure analysis of [P,N,O] species in singlet and triplet states at density functional theory and wavefunction-correlated levels

Abstract

The geometries and the harmonic vibrational frequencies for several PNO isomers in the singlet and triplet states have been predicted at density functional theory levels with a 6-311+G* basis set. Results have indicated that there are three linear structures, one bent and one cyclic structure in the singlet state, and three bent structures and one cyclic structure exist in triplet state. The ground state corresponds to a linear 1Σ PNO structure. The detailed bonding character is discussed, and the state–state energy separations of various stable states relative to the ground state are calculated. The state–state correlation is also predicted by searching the transition states and the intrinsic reaction coordinate analysis.