溴苯酚基态构型和红外频谱的理论计算

应用B3LYP/6-311＋＋G（d,p）水平上对溴苯酚的5种异构体进行了优化和频率分析来确定5种不同异构体的构型均为Cs点群.分析了这些构型的结构参数和电荷分布以及红外光谱的振动模式分配.与苯酚进行比较发现顺式异构体和反式异构体仅是电子相互作用的结果,而C1-O键长的缩短和OH键长的伸长体现了σ＊轨道上的电子转移.溴苯酚的红外频率的振动范围更大,模式更为复杂,出现了C-Br的新的振动模式,高频段范围的C-H的振动频率发生了蓝移.

Molecular Structures and Infrared Spectra of Bromophenol Theoretical Studies

The five structural isomers of bromophenol have been optimized and calculated with the density func- tional （B3LYP） methods using the extended 6-311 ＋ ＋ G （ d, p） basis set,the geometry structures has been deter- mined which are Cs point. Then the structural parameters, natural atomic charge, and frequency vibrational assign- ments of infrared spectra of these isomers of bromophenol have been analyzed and compared with phenol. The trans- and cis-isomers are the results of the electronic interaction. The shorten of OH and elongation of C1 - O showed the translation of the electrons on the σ＊ orbital. The range of the frequency vibrations of bromophenol is bigger and the mode is more difficult than phenol, new mode of C - Br is founded, the range of high frequency of the vibration of C - H has a blue-shift.