HPO_3异构体结构与稳定性

Structures and Stability of HPO_3 Isomers

使用密度泛函方法 (B3LYP)和 6 3 11++G( 3df ,3pd)基组计算得到了HPO3 体系的 9个异构体与 11个过渡态 ,并用内禀反应坐标理论验证了异构体的异构化过程 .结果表明 ,在HPO3 体系中 ,只有热力学最稳定的平面型异构体HOPO2(E1) ,(cis,cis)构象的HOOPO (E3 )和立体的具有Cs对称性的异构体HP(O)O2 (E7)具有较高的动力学稳定性 ,理论预测结果与实验一致 .另外 2个立体的HOPO2 连接方式的异构体 (E2和E4)由于解离为HO(Π) +OPO( 2 A1)的解离能较低 ,因此不能稳定存在 .

The potential energy surface (PES) of HPO3 system including nine isomers and eleven transition states was predicted at B3LYP/6-311 + + G(3df, 3pd) level of theory, and the connections were checked by intrinsic reaction coordinate calculations. The calculated results indicated that in HPO3 system thermodynamically the most stable species HOPO2 with planar structure (E1), (cis, cis) -HOOPO conformational isomer (E3), and stereo HP(O)O-2 with C-s symmetry, were found to have higher kinetic stability. The predicted results are in good agreement with previous experimental studies. Two new stereoisomers with HOPO2 connectivity obtained in this work were unstable because of their very low dissociation energies.