氯溴双卤代烷烃在太阳紫外光辐射下解离生成游离态的氯和溴自由基,它们是破坏臭氧的主要元凶之一。利用B3LYP/6-311++G(d,p)方法对氯溴 双卤代烷烃分子CnH2nBrCl(n=1～16)进行分子构型优化以及红外光谱的计算。根据数据进行分析比较,得到了氯溴双卤代烷烃C-Br键和C-Cl键 的键长、键角等构型参数随烷基支链长度增加(n为1～16)的变化趋势图。研究讨论了氯溴双卤代烷烃的红外 光谱相关振动随烷基支链长度增加的重要变化规律。

Solar UV radiation induces the dissociation of the chlorinated alkyl bromide with the product of free bromide radical and chlorine radical, which seriously damage the ozone layers. The molecular structure optimization and infrared spectra of chlorinated alkyl bromide CnH2nBrCl(n=1～16)were calculated by the[B3LYP/6-311++G(d, p)] basis set levels using density functional methods (DFT) approaches. Via comparison and discussion, the tendency of molecular structural parameters, like bond length, bond angle of CnH2nBrCl changing with the alkyl chain length increasing (n=1～16) are calculated. Meanwhile, the changing rules of C-Br and C-Cl vibration with the alkyl chain length increasing are also determined. Dependence of the molecular configuration and spectra of CnH2nBrCl on alkyl chain length (n) are obtained.