Abstract

European Journal of Mass Spectrometry
Volume 10 Issue 6, Pages 759–766 (2004)
doi: 10.1255/ejms.681

Heat of formation for the methylenimmonium cation by photoionization mass spectrometry

Zoë A. Harvey and John C. Traeger^*
Department of Chemistry, La Trobe University, Victoria 3086, Australia. E-mail: j.traeger@latrobe.edu.au

Photoionization mass spectrometry has been used to measure the CH₂NH₂⁺ appearance energies for six primary amines, resulting in a 298 K heat of formation of 749.5 ± 1.3 kJ mol^–1 for the methylenimmonium cation. An absolute proton affinity of 868.8 ± 2.5 kJ mol^–1 is derived for methylenimine. Based on experimental data for ethylenediamine, the 298 K heat of formation for the aminomethyl radical is found to be 153.6 ± 1.7 kJ mol^–1. These results are supported by high-level ab initio calculations.

Keywords: methylenimmonium cation (CH₂NH₂⁺), methylenimine (CH₂NH), aminomethyl (CH₂NH₂), photoionization, proton affinity, heat of formation, appearance energy

---

Full-text article (266 kB) (subscribers only)

Buy article on-line for £20 (get immediate access)

Alerting Service

 RSS Feed

Permalink: http://dx.doi.org/10.1255/ejms.681
QR Code (what is this?):

---