摘要
分别在MP2/3-21G!!、CCSD(T)/3-21G!!//MP2/3-21G!!和B3LYP/3-21G!!3种水平上,计算研究了气相反应Cl2+2HI=2HCl+I2的机理,求得一系列四中心和三中心的过渡态.通过比较六种反应通道的活化能大小,得到了相同的结论:双分子基元反应Cl2+HI"HCl+ICl和ICl+HI"I2+HCl的最小活化能小于Cl2、HI和ICl的解离能,从理论上证明了反应Cl2+2HI=2HCl+I2将优先以分子与分子作用形式分两步完成.用内禀反应坐标(IRC)验证了MP2/3-21G!!方法计算得到的过渡态.
The gas phase reaction mechanism of Cl2＋2HI=2HCl＋I2 has been investigated by MP2/3-21G^＊＊, CCSD（T）/3-21G^＊＊//MP2/3-21G^＊＊ and B3LYP/3-21G^＊＊ levels respectively, and a series of four-centred and threecentred transition states have been obtained. The following result is achieved by comparing the activation energies of six reaction paths. The activation energies of the bimolecular elementary reactions Cl2＋HI→HCl＋ICl and ICl＋HI→I2＋HCl are lower than the dissociation energies of Cl2, HI, and ICl. It is thus theoretically proved that the titled reaction occurs more easily in the bimolecular form with two intermediate steps. And finally the transition state calculated from MP2/3-21G^＊＊ method is validated by intrinsic reaction coordinate（IRC）.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2005年第9期961-966,共6页
Acta Physico-Chimica Sinica
基金
中国博士后科学基金会项目(2003033486)
江苏省高校自然科学研究项目(04KJB150149)资助~~
关键词
氯
碘化氢
Ab
INITIO
反应机理
双分子反应
Chlorine, Hydrogen iodide, Ab initio, Reaction mechanism, Bimolecular reaction
