TY  - JOUR
A1  - Choudhury, Arnab
A1  - DeVine, Jessalyn A. A.
A1  - Sinha, Shreya
A1  - Lau, Jascha Alexander
A1  - Kandratsenka, Alexander
A1  - Schwarzer, Dirk
A1  - Saalfrank, Peter
A1  - Wodtke, Alec Michael
T1  - Condensed-phase isomerization through tunnelling gateways
JF  - Nature : the international weekly journal of science
N2  - Quantum mechanical tunnelling describes transmission of matter waves through a barrier with height larger than the energy of the wave(1). Tunnelling becomes important when the de Broglie wavelength of the particle exceeds the barrier thickness; because wavelength increases with decreasing mass, lighter particles tunnel more efficiently than heavier ones. However, there exist examples in condensed-phase chemistry where increasing mass leads to increased tunnelling rates(2). In contrast to the textbook approach, which considers transitions between continuum states, condensed-phase reactions involve transitions between bound states of reactants and products. Here this conceptual distinction is highlighted by experimental measurements of isotopologue-specific tunnelling rates for CO rotational isomerization at an NaCl surface(3,4), showing nonmonotonic mass dependence. A quantum rate theory of isomerization is developed wherein transitions between sub-barrier reactant and product states occur through interaction with the environment. Tunnelling is fastest for specific pairs of states (gateways), the quantum mechanical details of which lead to enhanced cross-barrier coupling; the energies of these gateways arise nonsystematically, giving an erratic mass dependence. Gateways also accelerate ground-state isomerization, acting as leaky holes through the reaction barrier. This simple model provides a way to account for tunnelling in condensed-phase chemistry, and indicates that heavy-atom tunnelling may be more important than typically assumed.
Y1  - 2022
U6  - https://doi.org/10.1038/s41586-022-05451-0
SN  - 0028-0836
SN  - 1476-4687
VL  - 612
IS  - 7941
SP  - 691
EP  - 695
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  -