Low Temperature Physics: 36, 411 (2010); https://doi.org/10.1063/1.3432259 (6 pages)
Физика Низких Температур: Том 36, Выпуск 5 (Май 2010), c. 516-523    ( к оглавлению , назад )

Ion-molecule reactions of CoAr6+ with nitrogen oxides N2O, NO, and NO2: measuring absolute pressure by shock-freezing of the collision complex

C. van der Linde, R.F. Höckendorf, O.P. Balaj, and M.K. Beyer

Institut fьr Physikalische Chemie, Christian-Albrechts-Universitдt zu Kiel, OlshausenstraЯe 40, 24098 Kiel, Germany
E-mail: beyer@phc.uni-kiel.de

Received December 16, 2009, revised January 12, 2010


A new method to determine the absolute pressure in an ultra-high vacuum apparatus is tested using ion molecule reactions with CoAr6+. In a collision with a neutral reactant, the complex between Co+ and the collision partner is stabilized by evaporation of argon atoms. If CoAr6+ reacts with collision rate, the absolute pressure can be determined by comparing the experimental collision rate with the collision rate calculated from average dipole orientation theory. The experimental results with N2O, NO and NO2 indeed show that the collision complex is frozen out. Comparison of the rates of primary, secondary and tertiary reaction products, however, suggests that not all collisions of CoAr6+ are reactive.

PACS: 82.30.Fi Ion–molecule, ion–ion, and charge-transfer reactions.

Ключевые слова: FT-ICR mass spectrometry, pressure calibration, chemical kinetics, CoAr6+ cluster, nitrogen oxides, Ar-matrix, collision theory.