| Three major research projects are reported in this dissertation, as Part I, II and III. Part I mainly discusses the development and application of the pulsed-field ionization photoelectron secondary ion coincidence (PFI-PESICO) method together with guide ion beam (GIB) technique to study state-selected ion-neutral reaction dynamics in endstation 2 of Chemical Dynamics Beamline at Advanced Light Source. The endothermic proton transfer reaction, H2 + (X, v+ = 0--17, N+ = 1) + Ne, is investigated over a broad range of reactant vibrational energies. The kinetic and internal energy dependence of the reaction's cross sections is discussed.; Part II of this dissertation describes a high-resolution photoionization mass spectrometer (PIMS) to study free radicals prepared by a quasi-cw laser-dissociation source. Photoionization efficiency (PIE) measurements of the propargyl radical (C3H3), chloroformyl radical (CClO), and phenyl radical (C6H5) are presented. This study represents the first IE measurement for CClO. We find that the measured IE value of 9.990 +/- 0.003 eV is in accord with the Gaussian-2/Gaussian-3 theoretical predictions of 9.94/10.010 eV.; Part III discusses the results of 193 nm photodissociation dynamic studies of Chloroiodomethane (CH2ICl) using photofragment translation spectroscopy method. Tunable vacuum ultraviolet synchrotron radiation was used as a universal but selective ionization probe of the reaction products to reveal new aspects of the photodissociation dynamics. Four primary dissociation channels are observed: CH2Cl + I*(2P1/2)/I( 2P3/2), CH2I + Cl*(2P1/2 )/Cl(2P3/2), CHI + HCl, and CH2 + ICl. The state-selective detection has allowed us to identify the formation of iodine atoms in the ground state I(2P3/2) and the spin-orbit excited state I*(2P1/2), together with their branch ratio. On the basis of the time-of-flight measurements for photofragments, the dissociation mechanisms are discussed in details. |
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