Pes studies of some short lived molecules in the gas phase

The subject of this thesis is the study of the electronic structure of short-lived molecules in the gas-phase using ultraviolet photoelectron spectroscopy (p.e.s). Most of the molecules studied in this thesis have been prepared for p.e.s. investigation by rapid atom-molecule reactions although one molecule (SiS) was prepared by high temperature evaporation. After an introductory chapter (Chapter 1), the experimental methods used in this work are described in Chapter 2, and Chapter 3 describes the theoretical methods used to interpret the experimental photoelectron spectra. Chapters 4 to 8 describe the results obtained. A study of SiS with high temperature photoelectron spectroscopy is presented in Chapter 4. The main feature of this work is that breakdown of the one-electron ionisation model is observed for this molecule. In Chapter 5 a study of CH2NH2, produced from the F+CH3NH2 reaction, is described and in Chapter 6 a study of the isomeric radicals, acetyl and oxiranyl is presented. Chapter 7 presents the results of a study of the F+CH3CH2OH reaction and Chapter 8 discusses the results of some studies of the reaction of fluorine atoms with some halogenated ethanes. In Chapter 8, a comparison is made between the results obtained and those obtained for the CH2X (X = F, Cl, Br and I) radicals in some earlier p.e.s. studies.