甲醇/水混合团簇的多光子电离质谱研究

利用多光子电离技术结合飞行时间质谱仪对甲醇/水混合团簇进行了研究.在脉冲激光波长为355 nm条件下观测到团簇离子.主要的电离产物为质子化的(CH3OH)n(H2O)H+(n=l-13)混合团簇离子与(CH3OH)nH+团簇离子,经分析(CH3OH)1o(H2O) H+和(CH3OH)3H+为幻数结构.甲醇水混合团簇电离后团簇离子发生内部质子化转移反应是形成质子化团簇离子的主要原因.不同尺寸团簇离子信号强度随电离激光光强变化的光强指数曲线显示,团簇均发生四光子电离过程.

Multiphoton Ionization Mass Spectrum ofMethanol-water Complex Cluster

Methanol-water complex clusters have been studied by using multiphoton ionization technique and time-of-flight mass spectrometer. Laser with 355 nm wavelengths are used as ionized light source, protonated cluster ions (CH3OH)n(H2O)H+ (n=1-13) and (CH3OH)n H+ are observed. The formation of (CH3OH)n (H2O)H+ (n=1-13) is mainly through proton transfer reaction intra methanol-water clusters ions after laser multiphoton ionization. The experimental results show that (CH3OH)10(H2O)H+ and (CH3OH)3H+ are magic structure. The curve between laser power and different size cluster ion′s intensity indicate that the ionization undergoes a four-photon process.