Publikace ÚTF

The isotopic effects in reactions of O− ions with H2 and D2 have been studied experimentally using a cryogenic
22-pole radio-frequency ion trap. The rate coefficients for associative detachment leading to H2O + e− and to
D
2O + e− and for atom transfer reactions leading to formation of OH− and OD− ions were determined at
temperatures ranging from 15 to 300 K. The measured temperature dependencies of the rate coefficients for both
channels of reactions of O− with H
2 and D2 are compared with the results of the classical trajectory Monte Carlo
simulation of the O− + H2 and O− + D2 collisions using the newly calculated potential energy surfaces. The
measured temperature dependencies of the reaction rate coefficients for associative detachment are in very good
agreement with the calculated ones. Agreement between experimental and calculated temperature dependencies
of the rate coefficients of atom transfer reactions is off at most by a factor of 3 and the isotope effect is reproduced.