CAJ | 학술논문

通过共振拉曼光谱实验和量子化学计算的方法研究了4-硝基咪唑(4NI)A-带激发态衰变动力学。对4NI的振动光谱、紫外电子吸收光谱、荧光光谱和共振拉曼光谱进行了指认。在全活化空间自洽场法(CASSCF)/6-31G(d)计算水平下获得了单重激发态S1(nOπ*)和S2(ππ*)和势能面交叉点S1(nOπ*)/S2(ππ*)的优化几何结构和能量,分析了A-带共振拉曼光谱的强度模式特征,获得了短时结构动力学,并结合全活化空间自洽场法(CASSCF)理论计算结果确定了4NI在S2(ππ*)态衰变通道主要是S2, FC→S2, min(ππ*)→S0辐射弛豫。
통과공진랍만광보실험화양자화학계산적방법연구료4-초기미서(4NI)A-대격발태쇠변동역학。대4NI적진동광보、자외전자흡수광보、형광광보화공진랍만광보진행료지인。재전활화공간자흡장법(CASSCF)/6-31G(d)계산수평하획득료단중격발태S1(nOπ*)화S2(ππ*)화세능면교차점S1(nOπ*)/S2(ππ*)적우화궤하결구화능량,분석료A-대공진랍만광보적강도모식특정,획득료단시결구동역학,병결합전활화공간자흡장법(CASSCF)이론계산결과학정료4NI재S2(ππ*)태쇠변통도주요시S2, FC→S2, min(ππ*)→S0복사이예。
The A-band structural dynamics of 4-nitroimidazole (4NI) were studied using resonance Raman spectroscopy and quantum mechanical calculations, and the vibrational spectra, UV absorption spectra, fluorescence spectra, and A-band resonance Raman spectra were assigned. The resonance Raman spectra of 4-nitroimidazole were obtained in methanol with excitation wavelengths in resonance with the first intense absorption band, to probe the short-time structural dynamics. The optimized geometric structures and the excitation energies of the singlet excited states S1(nOπ*) and S2(ππ*), and the conical intersection point S1(nOπ*)/S2(ππ*), were computed at the complete active space self-consistent field (CASSCF)/6-31G(d) theory level. The intensity patterns of the A-band resonance Raman spectra were analyzed, and the results, together with those of the CASSCF calculations, revealed that the major decay channel initiated from the S2(ππ*) state was S2, FC→S2, min(ππ*)→S0 radiation.