摘要
用离子速度成像结合共振增强多光子电离技术研究了2-溴丁烷在233．62和11233．95nm的光解离动力学．从离子速度图像确定了光解产物Br和WBr^＊碎片的速度分布和角度分布．Br和Br^＊速度分布中包含的两个高斯分量是来自于2-溴丁烷在约234nm处的两个独立的光解离反应通道。高能的高斯分量对应于沿着C-Br伸缩模式的直接解离，低能的高斯分量对应于弯曲振动和C—Br伸缩振动耦合形成的排斥模式的解离．讨论了2-溴丁烷光解离中0Q0、0Q1和0Q1激发态对产物（Br和Br^＊）的贡献．在约234nm处Br（^2P3／2）的相对量子产率为0．924．
The photodissociation dynamics of 2-bromobutane has been investigated at 233.62 and 233.95 nm by ion-velocity map imaging technique coupled with resonance-enhanced multiphoton ionization. The speed and angular distribution of Br and Br＊ fragments were determined from the map images. The two Gaussian components, shown in the speed dis- tributions of Br and Br＊ atoms, are suggested to attribute to the two independent reaction paths of photodissociation for 2-bromobutane at 233.62 and 233.95 nm. The high-energy component is related to the prompt dissociation along the C-Br stretching mode, and the low-energy component to the dissociation from the repulsive mode with bending and C-Br stretching combination. The contributions of the excited 3Q0, 3Q1, and 1Q1 states to the products （Br and Br＊） were discussed. Relative quantum yield of 0.924 for Br（2P3/2） at about 234 nm in the photodissociation of 2-bromobutane is derived.
基金
This work was supported by the National Natural Science Foundation of China （No.21073177, No.20673107, and No.20873133）, the Ministry of Science and Technology of China （No.2007CB815203 and No.2010CB923302）, the Chinese Academy of Sciences （No.KJCX2-YW-N24 and No.KJCX2-EW-W09）, the Fundamental Research Funds for the Central Universities of China （No.WK2340000012）, and the USTC- NSRL Joint Funds （No.KY2340000021）.
关键词
离子速度成像
光解离
Ion-velocity imaging, Photodissociation, 2-bromobutane
