γ-巴豆酰内酯激发态动力学的共振拉曼光谱和完全活性空间自洽场(CASSCF)计算研究  

Excited State Dynamics of γ-Crotonolactone: Resonance Raman Spectroscopy and Complete Active Space Self-consistent Field(CASSCF) Study

作　　者：欧阳冰[1] 薛佳丹[1] 郑旭明[1] 

机构地区：[1]浙江理工大学化学系,先进纺织材料与加工技术教育部重点实验室,生态染整技术教育部工程研究中心,杭州310018

出　　处：《高等学校化学学报》2015年第10期1995-2001,共7页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21473163,21033002,20803066);国家“九七三”计划项目(批准号:2013CB834604)资助~~

摘　　要：采用共振拉曼光谱和完全活性空间自洽场(CASSCF)方法研究了γ-巴豆酰内酯的光吸收S2态的结构动力学和衰变机制.采用含时密度泛函理论方法结合光谱实验确认了紫外光谱和振动光谱.获得了涵盖A-带吸收的4个激发波长下的共振拉曼光谱.用CASSCF计算得到了S1,min,S2,min,T1,min,T2,min和T3,min及其相关势能面交叉点的结构与能量.研究了A-带共振拉曼光谱强度模式与S2,min和CI(S2/S1)交叉点结构的关系.借助El-Sayed规则分析了各系间窜跃路径的效率,提出了γ-巴豆酰内酯从S2,FC弛豫到基态S0的2条主要路径:内转换路径和系间窜跃路径.The structural dynamics and decay mechanisms of γ-crotonolactone in the light-absorbing S2 excited states were studied by resonance Raman spectroscopy and complete active space self-consistent field（CASSCF） computations. The electronic spectra assignments and the vibrational assignments were done on the basis of the density-functional theory computations and the results of corresponding spectra. The reso- nance Raman spectra at four excitation wavelength which covered A-band were obtained. CASSCF method was carried out to determine the minimal excitation energies and excited geometries of S1,min, S2,min, T1,min, T2,min , T3,min, as well as some conical intersection points. The relation between the structures of excited state S2,min as well as internal conversion point CI（S2/S1 ） and the intensity mode of resonance Raman spectra was studied. The efficiency of various intersystem crossing is evaluated on the basis of the El-Sayed＇ s rule, and two major decay channels from S2,FC to ground state SO were proposed. One is the internal conversion channel and the other is the intersystem crossing channel.

关 键 词：γ-巴豆酰内酯 共振拉曼光谱 完全活性空间自洽场(CASSCF)计算 结构动力学 非绝热动力学 内转换 系间窜跃 

分 类 号：O641[理学—物理化学]