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Communications: Infrared spectroscopy of gas phase ions: The cyclopropenyl and propargyl cations
1.J. Stieglitz, Am. Chem. J. 21, 101 (1899).
2.Stable Carbocation Chemistry, edited by P. R. Schleyer and G. K. Prakash (Wiley, New York, 1997).
3.Carbocation Chemistry, edited by G. K. Prakash and G. A. Olah (Wiley, New York, 2004).
4.T. Baer, C. Ng, and I. Powis, The Structure, Energetics and Dynamics of Organic Ions (Wiley, New York, 1996).
7.J. L. Holmes, C. Aubrey, and P. M. Mayer, Assigning Structures to Ions in Mass Spectrometry (CRC, Boca Raton, 2007).
8.T. W. Hartquist and D. A. Williams, The Molecular Astrophysics of Stars and Galaxies (Clarendon, Oxford, 1998).
16.V. I. Minkin, M. N. Glukhovstev, and B. Y. Simkin, Aromaticity and Antiaromaticity. Electronic and Structural Aspects (Wiley, New York, 1994).
32.A. Korth, M. L. Marconi, D. A. Mendis, F. R. Krueger, A. K. Richter, R. P. Lin, D. L. Mitchell, K. A. Anderson, C. W. Carlson, H. Rème, J. A. Sauvaud, and C. d'Uston, Nature (London) 337, 53 (1989).
35.M. W. Schmidt, K. K. Baldridge, J. A. Boatz, S. T. Elbert, M. S. Gordon, J. H. Hensen, S. Koseki, N. Matsunaga, K. A. Nguyen, S. Su, T. L. Windus, M. Dupuis, and J. A. Montgomery, J. Comput. Chem. 14, 1347 (1993).
36.M. S. Gordon and M. W. Schmidt, Theory and Applications of Computational Chemistry: The First Forty Years (Wiley, New York, 2002).
39.R. Bartlett, private communication (2009).
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ions produced with a pulsed discharge source and cooled in a supersonic beam are studied with infrared laser photodissociationspectroscopy in the region using the rare gas tagging method. Vibrational bands in the C–H stretching and fingerprint regions confirm the presence of both the cyclopropenyl and propargyl cations. Because there is a high barrier separating these two structures, they are presumed to be produced by different routes in the plasma chemistry; their relative abundance can be adjusted by varying the ion source conditions. Prominent features for the cyclopropenyl species include the asymmetric carbon stretch at and the asymmetric C–H stretch at , whereas propargyl has the scissors at 1445, the C–C triple bond stretch at 2077 and three C–H stretches (, , and ) at 3004, 3093, and . Density functional theory computations of vibrational spectra for the two isomeric ions with and without the argon tag reproduce the experimental features qualitatively; according to theory the tag atom only perturbs the spectra slightly. Although these data confirm the accepted structural pictures of the cyclopropenyl and propargyl cations, close agreement between theoretical predictions and the measured vibrational band positions and intensities cannot be obtained. Band intensities are influenced by the energy dependence and dynamics of photodissociation, but there appear to be fundamental problems in computed band positions independent of the level of theory employed. These new data provide infrared signatures in the fingerprint region for these prototypical carbocations that may aid in their astrophysical detection.
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