Abstract
We report the first observation of the infrared spectrum of the free tert-butyl cation in the gas phase. This ion is produced in a pulsed supersonic expansion equipped with a pulsed electrical discharge. C4H9+ is detected with a time-of-flight mass spectrometer. Its infrared spectrum is recorded using infrared photodissociation spectroscopy and the method of rare gas tagging with argon. For this, the C4H9+Ar complex is produced, mass selected, and studied with resonance-enhanced IR photodissociation spectroscopy using a tunable optical parametric oscillator laser system. Ab initio computations are employed at the MP2(fc)/6-311+G(2d,2p) level for various isomeric structures of C4H9+ and C4H9+Ar, and for various configurations of the tert-butyl cation, to elucidate the spectra. We find that argon has a negligible effect on the IR spectra and that the patterns in the spectrum are consistent only with the tert-butyl cation in a C1 or Cs configuration.
Original language | English |
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Pages (from-to) | 13782-13783 |
Number of pages | 2 |
Journal | Journal of the American Chemical Society |
Volume | 129 |
Issue number | 45 |
DOIs | |
State | Published - Nov 14 2007 |
Externally published | Yes |