Effect of the long-range potential on ion mobility measurements
The temperature dependence of ion mobilities in helium was studied by using the ion chromatography method to investigate the effect of long-range terms in the ion-buffer gas interaction. Experimental cross sections thus determined increased significantly as the temperature was lowered from 300 to 80 K for all ions investigated, which were fullerene C60+, cationized PEG polymers, cationized crown ethers, and protonated and sodiated oligoglycines. The temperature dependence of the collision cross sections was successfully modeled by employing simple atom-atom interaction potentials including a repulsive R−12 term and the attractive long-range R−6 and R−4 terms, R being the distance between the colliding particles.
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- 1.(a)Loeb, L. B. Basic Processes of Gaseous Electronics; University of California Press: Berkeley, CA, 1960;Google Scholar
- 1.(b)Massey, H. S. W. Electronic and Ionic Impact Phenomena, Vol. II; Clarendon: Oxford, 1969;Google Scholar
- 1.(c)McDaniel, E. W.; Mason, E. A. The Mobility and Diffusion of Ions in Gases Wiley: New York, 1973;Google Scholar
- 2.(d)Karpas, Z. Forensic Sci. Rev. 1990, 1, 103;Google Scholar
- 15.Shelminov, K. B.; Clemmer, D. E.; Jarrold, M. F. J. Chem. Soc. Dalton Trans. 1996, 567.Google Scholar
- 16.Allinger, N. L.; Zhou, X. F.; Bergsma, J. J. Mol. Struct. 1994, 312, 69.Google Scholar
- 20.Pearlman, D. A.; Case, D. A.; Caldwell, J. C.; Seibel, G. L.; Singh, U. C.; Weiner, P.; Kollman, P. A. AMBER 4. 0, University of California, San Francisco, 1991.Google Scholar
- 23.Wyttenbach, T.; Bowers, M. T., unpublished.Google Scholar