Mass Analyzed Threshold Ionization Spectroscopy Of Bromopropanes And Methylindoles

Zero kinetic energy (ZEKE) spectroscopy has proven to be a powerful technique for studies of molecular ions and offers a very high resolution. Mass analyzed threshold ionization (MATI) spectroscopy, i.e. mass analyzed ZEKE, which is developed in 1991, is closely related to ZEKE. It detects ions instead of electrons as detected in ZEKE and thus provides mass information at a comparable resolution level. MATI has become one of the major techniques for obtaining information about the properties of molecular ions as well as radicals, complexes and clusters. A large number of reliable data have been accumulated for physical, chemical and biological research fields. MATI spectroscopy has opened a powerful new field to carry out very high-resolution cation spectroscopy.Based on the MATI spectroscopy technique, this thesis focuses its interest mainly on studies of the molecular excited states and ionic states of several organic compounds. The main work can be summarized as following:1. Spectrum of the first electronic transition of m-xylene has been measured by resonance-enhanced multiphoton ionization (REMPI) in a time-of-flight (TOF) mass spectrometer. The band origin of S₁←S₀ electronic transition is found to be 36951 ±2 cm"1. These vibrationally resolved spectral features have been assigned on the basis of comparison with the results from ab initio and density functional theory calculations. This suggests that the substituents on benzene ring can influence the electronic...