Kinetic-energy release in Coulomb explosion of metastable C3H52+

Abstract

C 3 H 5 2+ , formed by electron impact ionization of propane, undergoes metastable decay into C2H2++CH3+. We have monitored this reaction in a magnetic mass spectrometer of reversed geometry that is equipped with two electric sectors (BEE geometry). Three different techniques were applied to identify the fragment ions and determine the kinetic-energy release (KER) of spontaneous Coulomb explosion of C3H52+ in the second and third field free regions of the mass spectrometer. The KER distribution is very narrow, with a width of about 3% [root-mean square standard deviation]. An average KER of 4.58±0.15 eV is derived from the distribution. High level ab initio quantum-chemical calculations of the structure and energetics of C3H52+ are reported. The activation barrier of the reverse reaction, CH3++C2H2+ (vinylidene), is computed. The value closely agrees with the experimental average KER, thus indicating that essentially all energy available in the reaction is partitioned into kinetic energy.

Ground‐state geometry and electronic structure of light atom clusters, especially H isotopes, Li, B, and C

“…But using Hartree-Fock theory as starting point, refined then by adding second-order Møller-Plesset perturbation corrections, Howard et al [32] have located a lowerenergy stable structure than that proposed in Ref. [31]. The energy difference is 1.05 eV for this 2ϩ hydrocarbon cation.…”

The stability of singly and multiply charged La@C80 and La@C82 ions determined from kinetic energy release measurements

“…The apparatus consists of a high resolution double-focusing mass spectrometer (Varian MAT CH5-DF) of reversed NierJohnson type BE1 geometry combined with a second electrostatic analyzer E2 [27,33]. The fullerene sample was, without further treatment, evaporated into a vacuum of about 10 −7 Torr from a temperature-controlled oven operating at 680 • C. The effusive beam is intersected by an electron beam.…”

“…As illustrated in recent publications [26][27][28][29][30], the problems can be avoided if the double-focusing mass spectrometer is combined with a second electrostatic analyzer. In the present work, we use such an instrument to measure MIKE spectra of singly and multiply charged La@C 80 z+ and La@C 82 z+ for z = 1-3.…”

Electron impact ionization of acetaldehyde

“…In our laboratory observations of metastable fragmentation reactions of ions produced by electron impact of molecules play a special role [3][4][5][6][7][8][9]. Just absence of metastable fragmentation reactions of acetaldehyde ions was for us direct encouragement for the investigations presented here.…”