氨/乙醇混合团簇多光子电离质谱

用多光子电离技术结合飞行时间质谱仪对氨与乙醇混合团簇进行了研究。在脉冲激光波长分别为266,355nm和532nm条件下,仅在355nm作用下观测到团簇离子。主要的电离产物为质子化的（C2H5OH）n（NH3）mH＋（n=0—3,m=0—4）混合团簇离子,且各个序列的离子强度随m的增大而减小。经分析,氨与乙醇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。通过理论计算得到其中性和离子团簇的稳定结构,解离能,解离通道。并证实团簇发生电离解离时发生了团簇内质子转移反应。

Multiphoton Ionization Mass Spectrum Research on Ammonia-Ethanol Complex Cluster

Ammonia-ethanol complex clusters were studied by multiphoton ionization technique and time-of-flight mass spectrometer.The wavelengths of pulse laser were 266,355nm and 532nm,and the cluster ions were only observed at 355nm.The main ionized products were protonated cluster ions（C2H5OH）n（NH3）mH＋（n=0—3,m=0—4）,and the various sequential ionic strength was decreased along with m.The cause of formation of（C2H5OH）n（NH3）mH＋ was mainly through proton transfer reaction intra ammonia-ethanol clusters ions after laser multiphoton ionization.The index curve between laser power and different size cluster ion＇s intensity indicated that the cluster all occurred ionization undergoes a four-photon process.The equilibrium conformations,dissociation channels and dissociation energies of neutral and ionic clusters were obtained by theoretical calculation.The proton transfer reaction intra ammonia-ethanol clusters ions occurred in the ionization and dissociation of clusters.