Ion molecule reactions in di-isopropyl ether

Abstract

The reactions of the ions at m/ z 43 and m/ z 45 which are formed by direct electron ionization of di-isopropyl ether with the parent molecules to produce ions at m/ z 61 may be examples of fast endothermic reactions. High pressure mass spectrometric studies indicated rapid reactions of these fragment ions with no significant temperature coefficients. Precise mass measurements and collisionally-induced decomposition studies indicate that the ion at m/ z 61 in di-isopropyl ether is a protonated alcohol. Trapped ion Fourier transform—ion cyclotron resonance studies gave rate constants for these reactions which were almost the same as the theoretical collision rate constants. Trapped ion studies in a Fourier transform—ion cyclotron resonance showed no significant radiative or collisional deactivation of the ions at m/ z 45 on the time scale of seconds, an observation which suggests that the reaction is not that of excited ions.