Grant Daniel J, Dixon David A, Kemeny Andre E, Francisco Joseph S
Chemistry Department, The University of Alabama, Shelby Hall, Box 870336, Tuscaloosa, Alabama 35487-0336, USA.
J Chem Phys. 2008 Apr 28;128(16):164305. doi: 10.1063/1.2902983.
High level ab initio electronic structure calculations using the coupled cluster CCSD(T) method with augmented correlation-consistent basis sets extrapolated to the complete basis set limit have been performed on the PNO, NOP, and NPO isomers and their corresponding anions and cations. Geometries for all species were optimized up through the aug-cc-pV(Q+d)Z level and vibrational frequencies were calculated with the aug-cc-pV(T+d)Z basis set. The most stable of the three isomers is NPO and it is predicted to have a heat of formation of 23.3 kcal/mol. PNO is predicted to be only 1.7 kcal/mol higher in energy. The calculated adiabatic ionization potential of NPO is 12.07 eV and the calculated adiabatic electron affinity is 2.34 eV. The calculated adiabatic ionization potential of PNO is 10.27 eV and the calculated adiabatic electron affinity is only 0.24 eV. NOP is predicted to be much higher in energy by 29.9 kcal/mol. The calculated rotational constants for PNO and NPO should allow for these species to be spectroscopically distinguished. The adiabatic bond dissociation energies for the P[Single Bond]N, P[Single Bond]O, and N[Single Bond]O bonds in NPO and PNO are the same within approximately 10 kcal/mol and fall in the range of 72-83 kcal/mol.
使用耦合簇CCSD(T)方法，并结合扩展至完整基组极限的相关一致基组，对PNO、NOP和NPO异构体及其相应的阴离子和阳离子进行了高水平的从头算电子结构计算。所有物种的几何结构在aug-cc-pV(Q+d)Z水平上进行了优化，并使用aug-cc-pV(T+d)Z基组计算了振动频率。三种异构体中最稳定的是NPO，预计其生成热为23.3千卡/摩尔。预计PNO的能量仅高1.7千卡/摩尔。计算得出NPO的绝热电离势为12.07电子伏特，绝热电子亲和势为2.34电子伏特。计算得出PNO的绝热电离势为10.27电子伏特，绝热电子亲和势仅为0.24电子伏特。预计NOP的能量要高得多，为29.9千卡/摩尔。计算得出的PNO和NPO的转动常数应能使这些物种通过光谱进行区分。NPO和PNO中P—N、P—O和N—O键的绝热键解离能在大约10千卡/摩尔范围内相同，在72 - 83千卡/摩尔之间。
