Charge-exchange mass spectra of thiophene, pyrrole and furan

Abstract

The absolute charge-exchange cross-sections, Q, in the gas phase between thiophene, pyrrole and furan and forty-eight primary positive ions of known ionisation potentials E_i,x have been measured. A plot of Q against E_i,x for a particular product ion constitutes that ion's charge-exchange mass spectrum, c.e.m.s., from which the ion's appearance potential is directly obtained. The appearance potentials of the three compounds and ten of their positive ion fragments are reported.