化学学报 ›› 2002, Vol. 60 ›› Issue (1): 49-54. 上一篇    下一篇

研究论文

HAsO~2异构体结构、相对稳定性与体系势能面

于海涛;池玉娟;傅宏刚;黄旭日;李泽生;孙家钟   

  1. 黑龙江大学化学化工学院;吉林大学理论化学研究所;吉林大学理论化学计算国家重点实验室
  • 发布日期:2002-01-15

The structures, relative stability, and potential energy surface of HAsO~2 isomers

YU HAITAO;CHI YUJUAN;FU HONGGANG;HUANG XURI;LI ZESHENG;SUN JIAZHONG   

  • Published:2002-01-15

在MP2/6-311++G(d,p)和QCISD(T)/6-311++G(3df,2p)(单点)水平下计算得到了包括9个异构体和10个过滤态的HAsO~2体系势能面。在势能面上,异构体cis-HOAsO(E1)的能量是最低的,其次是trans-HOAsO(E2)和HAsO(O)(C~2~V,E3),能量分别比cis-HOAsO高13.15和192.74kJ/mol。根据体系的势能面,异构体E1,E3及cis-HOOAs(E6),trans-HOOAs(E5)具有一定的动力学稳定性,在实验中应该可以观测到。AsH和O~2反应的第一步产物将会异构化为具有较高动力学稳定性的异构体E3;而OH和AsO反应可直接生成E1。计算结果与HPO~2,HPS~2,HNO~2,HNS~2等价电子相同的分子的势能面进行了比较。

关键词: 势能面, 异构化, 动力学, 稳定性, 过渡态理论, 亚砷酸

The potential energy surface (PES) of HAsO~2 system including nine isomers and ten transition states is predicated at MP2/6-311+ +G(d, p) and QCISD(T)/6-311+ +G(3df, 2p) (single-point) levels of theory. On the PES, cis-HOAsO(E1) is found to be thermodynamically the most stable isomer followed by trans-HOAsO(E2) and HAsO(O)(C~2~V, E3) at 13.15 and 192.74 kJ/mol. Based on the PES, E1, E3, cis-HOOAs(E6) and trans-HOOAs(E5) are thermodynamically and kinetically stable isomers, and should be experimentally observable. The products in the first-step reaction of HAs with O~2 can isomerize into isomer E3 that has higher thermodynamical stability. The reaction of OH with AsO will directly lead to the formation of isomer E1. The comparison of the calculated results with the PESs of HPO~2, HPS~2, HNO~2, HNS~2(analogs of HAsO~2) is also made.

Key words: POTENTIAL ENERGY SURFACES, ISOMERIZATION, DYNAMICS, STABILITY, TRANSITION STATE THEORY, ARSENOUS ACID

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