Article pubs.acs.org/JPCC
Single- versus Multi-Proton-Coupled Rydberg-State Electron Transfer in Amine Clusters Xiaohua Chen†,‡ and Yuxiang Bu*,† †
School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, People’s Republic of China School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, People’s Republic of China
‡
S Supporting Information *
ABSTRACT: Amino fragments (−NH2) are well-known to exist widely in biological systems and their protonated forms are inclined to trap electrons and form Rydberg radicals (−NH3•) in the electron-excess systems. Taking CH3−NH3+ as a mimicking group of the protonated alkylamine side-chain of lysine, ab initio calculations indicate that the proton/electron cooperatively transfer from CH3NH3 to CH3NH2 via a single-proton-coupled Rydberg-state electron transfer (ET) mechanism with an Rydberg-orbital channel for ET outside the −NHn hydrogens and a N−H+ → N proton migrating pathway. Besides, in big amine clusters, CH3NH3·(NH3)n·NH2CH3 (n = 1−3), the proton/electron transfer along an amine wire is stepwise and every step takes place via the similar single-proton-coupled Rydberg-state ET mechanism with low energy barrier (
