A theoretical study on the mechanisms of the N-2(X-1 Sigma(+)(g)) + O+(S-4(u)) reaction involving the 1(4) A '' and X-2 Pi states of the N2O+ ion and the predissociation of the X-2 Pi state

作者：Chang Hai Bo; Meng Qingyong; Huang Ming Bao^*; Dong Hua

来源：Molecular Physics, 2010, 108(16): 2137-2145.

DOI：10.1080/00268976.2010.507224

• CASPT2
• N2O+
• reaction
• adiabatic and nonadiabatic paths
• predissociation

The adiabatic path for the N-2(X-1 Sigma(+)(g)) + O+(S-4(u)) -> NO+(X-1 Sigma(+)) N(S-4(u)) reaction is presented based on the CASPT2 O-and N-loss dissociation potential energy curves (PECs) of the 1 4 A00 (not 1 4 '') state of N2O+ and it has a small barrier of 0.45 eV (0.34 eV with the CASSCF zero-point energy corrections) in good agreement with the experimental value of 0.33 +/- 0.08 eV. Based on the CASPT2 O-and N-loss dissociation PECs of the X-2 Pi state of N2O_and the calculated energies and spin-orbital coupling values at the located MECPs (minimum energy crossing points) for the X2 /1 4 A00 state pairs, a nonadiabatic path via the 1 4 A00/1 2 A00 O-loss MECP, X-2 Pi minimum, and 1 2 A ''/1 4 A00 N-loss MECP is presented. The CASPT2 energetic results indicate that this nonadiabatic process can occur without external energy. Based on the adiabatic and nonadiabatic paths, we explain the experimental facts for the reaction: small cross-section at low energy and an onset of a strong increase in cross-section at a certain energy value. Mechanisms for O-and N-loss predissociation of the X-2 Pi state by 1 4 A00 via the 1 2 A00/1 4 A00 O-and N-loss MECPs, respectively, are described, and the experimental facts are explained using the results of our energetic and spin-orbit coupling calculations.

• 出版日期2010
• 单位中国科学院; 西安近代化学研究所