氟利昂R12及其替代物的分子构型和特征光谱研究

Molecular structure and characteristic spectra of Freon-12 and its substitute

采用密度泛函理论对氟利昂R12及其替代物R134a在B3LYP/6-311G++(d,p)基组水平上进行结构优化和特征光谱计算.首次在该高精度基组下优化得到了R12和R134a的键长、键角和二面角等分子构型参数,且通过进一步的计算,得到了这两种分子的红外光谱和拉曼光谱.其中R12红外光谱的计算结果与美国国家标准局数据库(NIST)提供的实验结果基本吻合,说明了计算结果的准确性.另外通过从头算CIS方法对能量进行计算,得到了R12和R134a的紫外可见吸收光谱.计算结果可为进一步保护大气臭氧提供有用的数据参考.

The molecular structure optimization and characteristic spectra of Freon-12 and its substitute of Freon-134 a are obtained by density theory（ B3 LYP / 6-311G＋＋（ d,p）） calculations. The molecular configurable parameters,including bond length,bond angle and dihedral angle are calculated through high precise computation. The IR spectra and the Raman spectra of these two molecules are obtained by further calculation.The calculated IR spectra of Freon-12 are in good agreement with experimental results taken from National Institute of Standards and Technology,which proves to be accurate. Additionally,we get the UV-VIS spectra of Freon-12 and Freon-134 a by calculating energy with CIS method. The computing results offer useful reference for protecting atmospheric ozone layer.