乙胺分子的多光子电离过程质谱研究

报道了乙胺分子在４４０～４７５ｎｍ波长范围内多光子电离（ＭＰＩ）质谱（ＭＳ）研究结果。碎片离子主要由母体离子碎裂模式产生。母体离子ＣＨ３ＣＨ２Ｎ＋·Ｈ２由经３ｓ里德堡态的（２＋２）共振多光子电离产生后，大部分发生β键断裂，形成ＣＨ２＝Ｎ＋Ｈ２离子，还有一部分再吸收一个光子，通过Ｃ－Ｈ（ＣＨ２）键的断裂产生了ＣＨ３ＣＨ＝Ｎ＋Ｈ２离子。ＣＨ３ＣＨ＝Ｎ＋Ｈ２和ＣＨ２＝Ｎ＋Ｈ２离子最容易发生的碎裂过程是脱去氢分子，分别产生Ｃ２Ｈ４Ｎ＋（分子式）离子和ＣＨ≡Ｎ＋Ｈ离子。

Multiphoton Ionization Process Study of Ethylamine via Mass Spectrometry

The multiphoton ionization mass spectrum of ethylamine in the 440-484 nm region is studied. The MPI process follows the molecular ion fragmentation pattern. Most of the molecular ions fragment by β-cleavage after they have been formed from (2+2) resonance-enhanced multiphoton ionization through 3s Rydberg state. The fragment ion CH2=N+H2 is most abundant. A part of molecule ions absorb one photon, then the C-H(CH2) bond cleavage gives CH3CH=N+H2 ions. The easiest fragmentation pathway of CH2=N+H2 and CH3CH=N+H2 is the loss of H2 molecule, procucing CH=N+H and C2H4N+ ions respectively.