密度泛函理论研究苏丹红Ⅲ分子的电子结构、光谱与激发性质  

Study of the Electronic Structure,Spectrum,and Excitation Properties of Sudan RedⅢMolecule Based on the Density Functional Theory

作　　者：王一如[1] 高阳 吴永刚 王波 WANG Yi-ru;GAO Yang;WU Yong-gang;WANG Bo(School of Physics and Energy,Xuzhou University of Technology,Xuzhou 221018,China;Department of Physics,School of Science,Hainan University,Haikou 570228,China;Institute of Fundamental and Frontier Sciences,University of Electronic Science and Technology of China,Chengdu 610054,China;School of Physics and Electronic Science,Guizhou Education University,Guiyang 550018,China;School of Science,Northeast Electric Power University,Changchun 132012,China)

机构地区：[1]徐州工程学院物理与新能源学院,江苏徐州221018 [2]海南大学理学院物理系,海南海口570228 [3]电子科技大学基础与前沿研究院,四川成都610054 [4]贵州师范学院物理与电子科学学院,贵州贵阳550018 [5]东北电力大学理学院,吉林长春132012

出　　处：《光谱学与光谱分析》2023年第8期2426-2436,共11页Spectroscopy and Spectral Analysis

基　　金：吉林省教育厅基金项目(JJKH20180426KJ);贵州师范学院2021年度校级博士基金项目(2021BS013);国家自然科学基金项目(11904049);博士后科学基金项目(2019M653365)资助。

摘　　要：亲脂性偶氮染料苏丹红Ⅲ(Sudan RedⅢ)分子因染色后可使食品鲜艳、不褪色,常被放入食品添加剂中,食用后对人体的肝肾器官有明显的毒性作用,严重影响人类身体健康。苏丹红分子的毒性与其分子几何和电子结构密切相关,对其结构、电子激发等研究具有重要的指导意义。采用密度泛函理论(DFT)方法结合def2-TZVP基组对苏丹红Ⅲ分子结构、红外与拉曼光谱和紫外光谱进行系统研究,结果表明PBE0和B3LYP杂化泛函方法计算的红外和拉曼光谱与实验值吻合;采用含时的B3LYP杂化泛函计算得到的苏丹红Ⅲ分子的紫外-可见吸收峰为228、353和490 nm,与实验符合较好,它们是基态电子向第2激发态、第6激发态、第30激发态跃迁所致。采用空穴—电子分析法考察电子激发可知,S_(0)→S_(2)激发类型是氧、氮原子到萘环和苯环上的n—π*电荷转移激发,同时伴随着萘环、苯环环内间的π—π*局域激发。S_(0)→S 6激发类型是氮、氧原子到萘环,氮原子到苯环上的n—π*和萘环环内间π—π*电荷转移激发的叠加。S_(0)→S_(2)和S_(0)→S 6激发类型属于电荷转移激发为主的混合激发。S_(0)→S 30激发类型属于萘环环内的π—π*局域激发,同时也伴随着氧、氮原子到萘环上的n—π*和苯环到萘环上的π—π*电荷转移激发,S_(0)→S 30激发类型是以局域激发为主。通过分子片段对空穴、电子的贡献热图分析,进一步证实了上述电子激发转移过程。系统研究苏丹红Ⅲ分子的光谱及电子激发,为实验检测食品苏丹红Ⅲ分子提供理论参考。The lipophilic azo dye Sudan RedⅢmolecule enhances flavor or makes food bright and attractive.After eating,it has noticeable toxic effects on the liver and kidney organs of the human body and seriously affects human health.The toxicity of Sudan red molecule is closely related to its molecular geometry and electronic structure,which has important guiding significance for studying its structure and electronic excitation.In this work,we aimed to systematically investigate the molecular structure,infrared and Raman spectra,and ultraviolet spectra of Sudan RedⅢby using the density functional theory(DFT)method in conjunction with the def2-TZVP basis set.The excitation properties of Sudan RedⅢwere also studied in detail by the hole-electron analysis method.The results show that the infrared and Raman spectra calculated for Sudan RedⅢusing the PBE0 and B3LYP exchange-correlation functional agree with the experimental data.Using the time-dependent B3LYP(TD-B3LYP)method with the def2-TZVP basis set,The UV-visible absorption peaks of Sudan RedⅢshow 228,353,and 490 nm,which are in good agreement with the experiments.It can be found that they are through the transition of the ground state electrons to the second excited state,the sixth excited state,and the 30th excited state.The electron excitation characteristics are studied by using hole-electron analysis.It can be found that S_(0)→S_(2)is attributed to the superposition of the n—π*charge-transfer excitation in the direction from oxygen and nitrogen atoms to the naphthalene and benzene ring,and theπ—π*local excitation between intra-ring naphthalene and benzene rings.The superposition of the n—π*charge-transfer excitation from oxygen and nitrogen atoms to naphthalene and benzene ring and theπ—π*local excitation between intra-ring naphthalene and benzene rings are excited by S_(0)→S 6.The electronic transition of S_(0)→S_(2)and S_(0)→S 6 from the ground state to the excited state belongs charge transfer excitation,where the charge transfer exc

关 键 词：密度泛函理论 苏丹红Ⅲ分子 空穴-电子分析法 红外与拉曼光谱 紫外-可见光谱 电子激发 

分 类 号：O561.4[理学—原子与分子物理]