This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1002/jms.3917 This article is protected by copyright. All rights reserved. Thermal dissociation of ions limits the degree of the gas-phase H/D exchange at the atmospheric pressure. AUTHOR NAMES Yury Kostyukevich a,b,c,d , Alexey Kononikhin b,d , Igor Popov c,d , and Eugene Nikolaev a,b,c,d AUTHOR ADDRESS a Skolkovo Institute of Science and Technology Novaya St., 100, Skolkovo 143025 Russian Federation b Institute for Energy Problems of Chemical Physics Russian Academy of Sciences Leninskij pr. 38 k.2, 119334 Moscow, Russia; c Emanuel Institute for Biochemical Physics Russian Academy of Sciences Kosygina st. 4, 119334 Moscow, Russia. d Moscow Institute of Physics and Technology, 141700 Dolgoprudnyi, Moscow Region, Russia