范德华络合物Rg-HCl、Rg-ClH(Rg=Ne,Ar)异构化的量子化学及热力学的分析

The Thermodynamic and Quantum Chemical Analysis of Isomerization of Van Der Waals Complexes Rg-HCI.Rg-CIH(Rg = Ne, Ar)

对标题异构化体系，在 Ｇａｕｓｓｉａｎ ９４程序的高水平 ＭＰ４／６－３１１Ｇ＊＊下，进行了全参数几何优化、能量、频率等计算，得到了它们电子结构的相对稳定性。同时用统计热力学计算了Ｒｇ－ＨＣＩ、Ｒｇ－ＣＩＨ（Ｒｇ＝ Ｎｅ， Ａｒ）等异构体的热力学性质及它们的相互转化的平衡常数等。结果表明：不同构型的稳定性是随实验温度变化的，两种构型也可在某一温度下共存。这一结果不同于仅通过电子结构能所作出的某异构体较稳定的简单推断，而是提醒人们对一些弱键体系，要考虑温度与熵效应的重要性。

For the isomerous system in the title, using the high-level mp4/6-311G * * of Gaussian 94 we have optimized their structures with full parameters, also we have computed their energies and frequencies. Their relative stability is obtained on the basis of energies of their electron structures. Meanwhile, we computed thermodynamic functions of Rg-HCl and Rg-ClH as well as equilibrium constant k of transformation reaction. All the results indicated that stabilities of different structures are dependent of experimental temperature, Rg-HCl and Rg-ClH may coexist with each other at certain temperature. The conclusion obtained is different from that derived from superficial analysis of energy of electronic structure, it reminds us that we shall take into account temperature and entropic effect while we deal with some weak-bond systems.