Accession Number : AD0603314

Title :   A HIGH PRESSURE MASS SPECTROMETRIC STUDY OF NEOPENTANE,

Descriptive Note : Technical rept.,

Corporate Author : HUMBLE OIL AND REFINING CO BAYTOWN TEX

Personal Author(s) : Henchman,M. J. ; otwinowska,H. T. ; Field,F. H.

Report Date : JUL 1964

Pagination or Media Count : 1

Abstract : An A. E. I. Metropolitan-Vickers MS-2 mass spectrometer was modified to permit operation up to about 0.2 Torr, and a brief description of the modification is given. The instrument was used to investigate the ionmolecule reactions occurring at high pressures in neopentane. The extent of these reactions is appreciably smaller than those observed in the lighter alkanes. No ions with mass greater than the parent mass of neopentane (m/e = 72) are observed. From appearance potentials it is concluded that at threshold the product ions are formed from C3H5(+) and/or C2H5(+). The pressure plots indicate that m/e = 15 (CH3(+)), m/e = 27 (C2H3(+)), and m/e = 29 (C2H5(+)) react and m/e = (C3H3(+)) and m/e = 41 (C3H5(+)) react and are formed. Rate constants were obtained for the three reactant ions. Mass spectra of neopentane were obtained at low values of the ionizing voltage (EV = 9-14 volts). Evidence was obtained for the occurrence of several collision-induced dissociation processes, but the forms of the pressure plots for the ions produced are not understood. (Author)

Descriptors :   (*MASS SPECTROSCOPY, HYDROCARBONS), (*ALIPHATIC COMPOUNDS, MASS SPECTRA), (*HYDROCARBONS, MASS SPECTRA), IONS, MOLECULES, CHEMICAL REACTIONS, HIGH PRESSURE, IONIZATION POTENTIALS, REACTION KINETICS, DISSOCIATION, SPECTRUM ANALYZERS

Distribution Statement : APPROVED FOR PUBLIC RELEASE