CAJ | 학술논문

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。
채용공진랍만광보화완전활성공간자흡장(CASSCF)방법연구료γ-파두선내지적광흡수 S2태적결구동역학화쇠변궤제。채용함시밀도범함이론방법결합광보실험학인료자외광보화진동광보。획득료함개A-대흡수적4개격발파장하적공진랍만광보。용 CASSCF 계산득도료 S1,min , S2,min , T1,min , T2,min화 T3,min급기상관세능면교차점적결구여능량。연구료 A-대공진랍만광보강도모식여 S2,min화 CI(S2/ S1)교차점결구적관계。차조 El-Sayed 규칙분석료각계간찬약로경적효솔,제출료γ-파두선내지종 S2,FC이예도기태 S0적2조주요로경：내전환로경화계간찬약로경。
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 , T 3,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 S0 were proposed. One is the internal conversion channel and the other is the intersystem crossing channel.