甲胺分子的同步辐射光电离解离质谱  

Photoionization and photodissociation mass spectroscopy of methylamine by synchrotron radiation

作　　者：胡正发[1] 王振亚[1] 孔祥蕾[1] 张先燚 李海洋[1] 周士康[1] 王娟[2] 武国华[2] 盛六四[2] 张允武[2] 

机构地区：[1]中国科学院安徽光学精密机械研究所环境光谱学实验室,合肥230031 [2]中国科学技术大学国家同步辐射实验室,合肥230026

出　　处：《物理学报》2002年第2期235-239,共5页Acta Physica Sinica

基　　金：中国科技大学国家同步辐射实验室资助的课题~~

摘　　要：在超声射流冷却条件下 ,利用同步辐射光源 ,结合飞行时间质谱对CH3 NH2 分子在 6 0— 140nm波长范围内的光电离解离进行了研究 .主要动力学过程为母体离子的解离过程 .CH2 NH2 +和CH3 +由CH3 NH2 +在高能量时解离生成 ,而CH2 NH2+的 1,1脱H2 过程则产生其他离子 .CH3 NH2 分子的电离势 (IP)为 9 16± 0 0 1eV ,和分子轨道能量计算的理论值符合得非常好 ,并获得CH3 NH2+和CH2 NH2+的生成热分别为 86 0± 0 5kJ mol和 75 4 1kJ mol.Photoionization and photodissociation experiments of methylamine, by using synchrotron radiation(60 similar to 140nm) combining with time of flight-mass spectroscopy (TOF-MS), have been performed under supersonic molecular beam. Ions of CH2NH2+ and CH3+ (high energy) are produced from fragmentation of parent ion CH3NH2+, however, other fragment ions is attributed to 1, 1-H-2 eliminated process of CH2NH2+. The photoionization efficiency curve of CH3NH2+ ion indicates that the ionization energy (IE) of methylamine is 9.16 +/- 0.01eV, which agrees with the values computed by molecular orbital methods very well. The heats of formation of CH3NH2+ and CH2NH2+ are also obtained to be 860 +/- 0.5kJ/mol and 754.1kJ/mol respectively.

关 键 词：同步辐射光电离 飞行时间质谱 电离势 生成热 甲胺分子 CH3NH2 解离过程 

分 类 号：O657.63[理学—分析化学]