Charge transfer mass spectra of isomers I. n-C 4H 10 and i-C 4H 10

Abstract

Charge transfer mass spectra of i-butane have been obtained with slow positive ions. The spectra have been used to construct the breakdown curve, that is the mass spectrum as a function of the energy transferred to the molecule in the ionization. This is compared with the curve for n-butane [5] and with QET calculations [6], and the differences are discussed. The calculations give good agreement up to ca. 17 eV. The breakdown curves show that isomerization between the i-butane and n-butane molecular ions is not probable at low excitation energies. Proton and hydride ion transfer with i-butane have been observed for a number of slow positive ions. Ion-molecule reactions in the i-butane gas have been investigated using Ar + and Ne + for the initial ionization.