离子速度成像方法研究C8H17Br分子的光解动力学

用离子速度成像方法, 研究了长链C8H17Br分子在234 nm激光下的光解过程. 通过2+1共振增强多光子电离探测了两种光解产物Br*(2P1/2)和Br(2P3/2), 得到了它们的相对量子产率. 从光解产物Br*(2P1/2)和Br(2P3/2)的速度图像得到了能量和角度分布. 并根据相对量子产率和角度分布, 计算了不同解离通道的比例. 实验发现C8H17Br分子解离过程中大部分能量都转化为内能, 该能量分配可以较好地用软反冲模型来解释, 并分析了这种能量分配跟烷基大小的关系.

Study on Photodissociation Dynamics of C8H17Br by Velocity Map Ion Imaging

The Photodissociation dynamics of C8H17Br with excitation laser at 234 nm has been studied using velocity map ion imaging. The relative quantum yields are obtained from (2 1) resonance-enhanced multiphoton ionization (REMPI) of the photofragment Br*(2P1/2) and Br(2P3/2). The velocity maps provide detail information on translational energy distributions and angle distributions. The probabilities of the individual pathways of the fragments are calculated from the relative quantum yield and angular distribution. The results indicate that a large fraction of the available energy translates into the internal energy of the fragments, which can be explained using the soft impulsive model. The relationship between the energy partition and the alkyl structure has been analysed.