对二甲苯光谱的理论计算  

Theoretical Calculation of Spectra of Para-xylene

作　　者：杜建宾[1] 张倩[1] 唐延林[2] 张亚如[1] 

机构地区：[1]廊坊师范学院,河北廊坊065000 [2]贵州大学,贵州贵阳550025

出　　处：《廊坊师范学院学报（自然科学版）》2014年第4期47-48,52,共3页Journal of Langfang Normal University(Natural Science Edition)

基　　金：国家自然科学基金(41061039;11164004);廊坊师范学院自然青年基金(LSZQ201105)

摘　　要：采用密度泛函(DFT)B3LYP方法在6-311++G(d,p)基组水平上优化计算了对二甲苯(para-xylene PX)分子的基态稳定几何构型及其红外(IR)光谱,并利用含时密度泛函(TDDFT)在同一基组下研究了PX分子的前26个激发态和紫外-可见(UV-Vis)吸收光谱。结果表明,PX分子的IR光谱的最强吸收由甲基上C-H的伸缩振动所产生;UV-Vis光谱的最强吸收出现在苯环上π→π*电子跃迁的E带,较强吸收出现在甲基上C-H基团的σ→σ*跃迁。In this paper, para-xylene＇s geometrical parameters of the ground state and infrared （IR） spectrum are cal- culated by utilizing the density functional theory B3LYP method at the level of 6 - 311 ＋ ＋ G（d, p）. On this basis, the first twenty-six excited states and the UV-Vis absorption spectra of PX are studied by using the time-dependent density functional theory （TDDFT） in the same fundamental group. The results show that the strong absorption of IR spectra of PX is produced by C-H of methyl telescopic vibration producing. The most strongest absorption of UV-Vis absorption spectra appears in the E belt of benzene electronic transition from π to π ^＊ , and the stronger absorption from C-H of methyl σ to σ^＊ .

关 键 词：对二甲苯 光谱 DFT TDDFT 

分 类 号：O433[机械工程—光学工程]