Structural Isomerization of the Gas‐Phase 2‐Norbornyl Cation Revealed with Infrared Spectroscopy and Computational Chemistry |
| |
| Authors: | Jonathan D Mosley Dr Justin W Young Dr Jay Agarwal Prof Henry F Schaefer III Prof Paul v R Schleyer Prof Michael A Duncan |
| |
| Affiliation: | 1. Department of Chemistry, University of Georgia, Athens, GA 30602 (USA) http://maduncan.myweb.uga.edu;2. Center for Computational Quantum Chemistry, University of Georgia, Athens, GA 30602 (USA) |
| |
| Abstract: | In an attempt to produce the 2‐norbornyl cation (2NB+) in the gas phase, protonation of norbornene was accomplished in a pulsed discharge ion source coupled with a supersonic molecular beam. The C7H11+ cation was size‐selected in a time‐of‐flight mass spectrometer and investigated with infrared laser photodissociation spectroscopy using the method of “tagging” with argon. The resulting vibrational spectrum, containing sharp bands in the C? H stretching and fingerprint regions, was compared to that predicted by computational chemistry. However, the measured spectrum did not match that of 2NB+, prompting a detailed computational study of other possible isomers of C7H11+. This study finds five isomers more stable than 2NB+. The spectrum obtained corresponds to the 1,3‐dimethylcyclopentenyl cation, the global minimum‐energy structure for C7H11+, which is produced through an unanticipated ring‐opening rearrangement path. |
| |
| Keywords: | carbocations computational chemistry ion spectroscopy mass spectrometry |
|
|
