对苯二胺和对硝基苯胺的分子结构与光谱对比研究  

A comparative study of the structures and spectra of p-phenylene diamine and p-nitroaniline

作　　者：李茜 高爱华 陆镝莱[2] 赵普举 郑继明[3] 姜振益[4] 钱程 LI Qian;GAO Aihua;LU Dilai;ZHAO Puju;ZHENG Jiming;JIANG Zhenyi;QIAN Cheng(School of Physics, Northwest University, Xi′an 710127, China;School of Chemical Engineering, Northwest University, Xi′an 710069, China;National Key Laboratory of Photoelectric Technology and Functional Materials in Shaanxi Province,Northwest University, Xi′an 710127, China;Institute of Modern Physics, Northwest University, Xi′an 710127, China;College of Chemistry and Materials Science,Northwest University, Xi′an 710127, China)

机构地区：[1]西北大学物理学院,陕西西安710127 [2]西北大学化工学院,陕西西安710069 [3]西北大学光电子技术与功能材料国家重点实验室,陕西西安710127 [4]西北大学现代物理研究所,陕西西安710127 [5]西北大学化学与材料科学学院,陕西西安710127

出　　处：《西北大学学报（自然科学版）》2020年第6期960-970,共11页Journal of Northwest University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(51872227);陕西省教育厅专项科研基金资助项目(17JK0763);西北大学本科教学工程项目(JX17074)。

摘　　要：为了解对苯二胺和对硝基苯胺的光谱与结构间的关系,利用DFT/B3LYP/6-311G(d,p)方法对其光谱信息进行了计算。考虑到模拟计算和实验测量间的差异,对计算的振动频率进行了合理的标度修正,发现修正后的计算值和实验值符合得很好。由于硝基和氨基结构不同,使得对硝基苯胺中对应基团(NH2、C—H、C—C)的振动频率略高于对苯二胺。对苯二胺与对硝基苯的13C和1H的核磁共振化学位移,选用等电聚焦连续极化模型(IEF-PCM)以二甲基亚砜为溶剂,采用规范不变的原子轨道法(GIAO)进行了计算,与对苯二胺相比,对硝基苯胺的对位(δC3)以及邻位(δC1、δC5、δH7、δH10)上化学位移增大,而间位(δC2、δC4)上化学位移减小。采用自然键轨道理论,对分子的前线轨道进行了分析;同时采用含时密度泛函理论,以水和气相为环境对两分子的电子光谱进行了计算,结合实验对对苯二胺和对硝基苯胺在紫外可见区的特征吸收峰对应的电子跃迁类型进行了指认。To understand the relationship between the spectra and the structures of p-phenylene diamine and p-nitroaniline,the spectral information was calculated by using DFT/B3LYP/6-311G(d,p)method.Taking into account the differences between the calculated and experimental samples,the calculated frequencies were reasonably scaled.It was found that the theoretically calculated vibration frequencies scaled reasonably were in agreement with the experimental data.Due to the differences of-NO2 and-NH2 in structure,the vibration frequency of the corresponding groups(NH2,C—H and C—C)of p-nitroaniline was slightly higher than that of p-phenylene.1H and 13C nuclear magnetic resonance chemical shift of the two compounds have been calculated based on gauge-including atomic orbital method(GIAO)with isoelectric focusing polarization continuum model(IEF-PCM)in dimethyl sulfoxide solution.Compared with p-phenylene,chemical shifts of p-position(δC3)and o-position(δC1,δC5,δH7,δH10)of p-nitroaniline increased,and meta position(δC2,δC4)chemical shifts decreased.Besides,the frontier molecular orbitals of title molecules were obtained through natural bond orbital analysis;Ultraviolet visible spectra were calculated by time dependent density functional theory(TD-DFT)in water and gas phase.The electronic transition types of the characteristic absorption peaks of p-phenylene diamine and p-nitroaniline in ultraviolet visible region were identified combined with the experiment data.

关 键 词：对苯二胺 对硝基苯胺 密度泛函理论(DFT) 振动光谱(FTIR FT-Raman) 核磁共振(NMR) 紫外可见(UV-Vis) 

分 类 号：O433.5[机械工程—光学工程]