355nm激光作用下二甲胺的多光子电离质谱研究  

Study on multiphoton ionization mass spectrum of dimethylamine at 355nm laser radiation

作　　者：郎济刚[1] 孔祥和[1] 张树东[1] 宋宝[1] 宿光勇[1] 

机构地区：[1]曲阜师范大学物理工程学院,山东曲阜273165

出　　处：《激光杂志》2009年第6期22-23,共2页Laser Journal

基　　金：曲阜师范大学博士科研启动基金资助

摘　　要：利用多光子电离技术结合飞行时间质谱仪,在355nm激光作用下对二甲胺分子进行了研究,我们认为其主要经历了2+1的REMPI过程,二甲胺母体离子α断裂产生CH3N+H=CH2,CH3N+H=CH2进一步解离产生C2H4N+,用从头算方法确定了m/e=42的离子是(CH3N≡CH)+,对m/e=28的离子的可能来源进行了推测:一是(CH3N≡CH)+离子进一步发生重排,失去CH2游离基;二是CH2=N+H21,2脱氢。The dimethylamine was studied by using multiphoton ionization technique and time-of-flight mass spectrometer under the radiation of the 355nm laser.we draw the conclusion that it mainly undergoes the 2＋1 REMPI process.The dimethylamine parent ion has gone through the α cleavage to produce CH3N＋H=CH2 fragment which later dissociates to C2H4N＋ fragment.The paper also obtains the result that the m/z 42 fragment is（CH3N≡CH）＋by the ab initio calculations,and,meanwhile,make speculation of the possible sources of m/z 28 fragment.One case is that the（CH3N≡CH）＋ undergoes the further rearrangement that causes the loss of CH2 radical.The other case is that the 1,2-hydrogen elimination from CH2=N＋H2.

关 键 词：多光子电离 飞行时间质谱 二甲胺 重排 

分 类 号：O561[理学—原子与分子物理]