Some advances in gas phase photoelectron spectroscopy

The apparatus and techniques applicable to experimental Photoelectron Spectroscopy and theoretical Molecular Orbital calculations are described in detail. The first three photoelectron bands of the fluorine monuxide (F0, X2II) radical have been identified experimentally. Analysis of the experimental data lead to accurate adiabatic ionization potentials and ionic state frequencies. Assignment of the bands was aided by the results of ab initio molecular orbital calculations. The gas phase reaction of fluorine atoms with hydroisocyanic acid (HNCO) was investigated. No evidence could be found in the observed spectra for the isocyanate radical (NCO). However fluorine cyanate (FOCN) was proposed as the primary product of the radical quenching reaction. Detailed theoretical calculations yielded accurate potential energy curves for hydrogen fluoride (HF) and its two lowest cationic states (HF+(X2II) and HF`(a2E+)). Vibrational band envelopes in the HeI photoelectron spectrum were computed for ionization from various vibrationally excited states of HF. In addition design details, and initial results, are given for a multidetector Photoelectron Spectrometer.