Resonance Raman and theoretical investigation of the photodissociation dynamics of benzamide in S3 state.
Resonance Raman and theoretical investigation of the photodissociation dynamics of benzamide in S3 state.
复制标题
DOI：
10.1063/1.2938373
复制
发表时间：
2008-06
期刊：
影响因子：
--
通讯作者：
Kemei Pei;Yufang Ma;Xuming Zheng
中科院分区：
文献类型：
--
作者：
Kemei Pei;Yufang Ma;Xuming Zheng
用共振拉曼光谱研究了苯甲酰胺在甲醇和乙腈溶液中的激发波长与S（3）态的共振。这些光谱表明，Franck-Condon区光解动力学具有多维特征，主要沿苯环C[双键]C伸缩沿着、Ph-CO-NH（2）和环苯伸缩nu（9）、CCH平面弯曲nu（17）、Ph-CO-NH（2）伸缩和NH（2）摇摆nu（19）、环三角弯曲nu（23）、环形变和Ph-CO-NH（2）伸缩nu（29）。进行了初步的共振拉曼强度分析，并将结果与先前报道的苯乙酮进行了比较，以检查取代基效应。溶剂效应对苯甲酰胺的短时光解动力学也进行了研究。用完全活性空间自洽场论计算方法确定了苯甲酰胺分子S（3）和S（2）势能面的一个圆锥交点S（2）S（3）。研究了S（3）S（2）点与S（0）点的结构异同，并将其与苯甲酰胺S（3）态的Franck-Condon光解动力学进行了关联.
Resonance Raman spectra were obtained for benzamide in methanol and acetonitrile solutions with excitation wavelengths in resonance with the S(3) state. These spectra indicate that the Franck-Condon region photodissociation dynamics have multidimensional character with the motions mainly along the benzene ring C[Double Bond]C stretch nu(9), the Ph-CO-NH(2) and ring benzene stretch nu(14), the CCH in plane bend nu(17), the Ph-CO-NH(2) stretch and NH(2) rock nu(19), the ring trigonal bend nu(23), and the ring deformation and Ph-CO-NH(2) stretch nu(29). A preliminary resonance Raman intensity analysis was done, and the results were compared to those previously reported for acetophenone to examine the substituent effect. Solvent effect on the short-time photodissociation dynamics of benzamide was also examined. A conical intersection point S(2)S(3) between S(3) and S(2) potential energy surfaces of benzamide was determined by using a complete active space self-consistent field theory computations. The structural differences and similarities between S(3)S(2) point and S(0) were examined, and the results were used to correlate to the Franck-Condon photodissociation dynamics of benzamide in S(3) state.