Fast ortho-to-para conversion of molecular hydrogen in chemisorption and matrix-isolation systems

Frontiers in Chemistry

Chemistry

Hirokazu Ueta¹  Koichiro Yamakawa¹  Katsuyuki Fukutani² 

[1] Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan;Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan;Institute of Industrial Science, The University of Tokyo, Tokyo, Japan;

关键词: hydrogen;    nuclear spin;    rotational energy;    adsorption;    surface;    matrix isolation;   

DOI  :  10.3389/fchem.2023.1258035

 received in 2023-07-13, accepted in 2023-07-27,  发布年份 2023

来源: Frontiers

【 摘 要 】

Molecular hydrogen has two nuclear-spin modifications called ortho and para. Because of the symmetry restriction with respect to permutation of the two protons, the ortho and para isomers take only odd and even values of the rotational quantum number, respectively. The ortho-to-para conversion is promoted in condensed systems, to which the excess rotational energy and spin angular momentum are transferred. We review recent studies on fast ortho-to-para conversion of hydrogen in molecular chemisorption and matrix isolation systems, discussing the conversion mechanism as well as rotational-relaxation pathways.

【 授权许可】

Unknown   
Copyright © 2023 Ueta, Fukutani and Yamakawa.