采用量子化学中的密度泛函理论 (DFT) ,在 B3LYP/ 6 - 311+G(3df,2 p)水平上全优化得到了单卤代二硫烷 HSSX(X=H,F,Cl,Br)链型和分叉型两种异构体的平衡结构。计算结果表明 ,在热力学上 ,所有链型的 HSSX为稳定构型 ,其能量分别较分叉型构型低 10 9.8、6 0 .2、74 .8和 73.1k J/ mol。同时 ,采用统计热力学方法 ,研究了两种平衡结构之间相互转化的化学热力学性质 ,发现异构化反应的平衡常数很小。 Using the density functional theory (DFT) in quantum chemistry, the monohalogenated disulfane HSSX (X = H, F, Cl, Br) has been fully optimized at B3LYP / 6 - 311 + G ) Chain and bifurcation of the two isomers of the equilibrium structure. The calculated results show that in the thermodynamics, all chain-type HSSXs are in a stable configuration, and their energies are 10 9.8, 60.2, 74.8 and 73.1 kJ / mol lower than that of the bifurcated configuration, respectively. At the same time, using statistical thermodynamics method, the thermodynamic properties of the two equilibrium structures were studied, and the equilibrium constants of the isomerization reaction were found to be small.