Probing Composition Effects on the Intrinsic Energetics of Proton Transfer in Binary (HCl)m(H2O)n Clusters
ACS Citation
Tucker, M.R.; Arradondo, S.N.; Longsworth, O.M.; Shields, G.C.; Tschumper, G.S. Probing Composition Effects on the Intrinsic Energetics of Proton Transfer in Binary. ChemPhysChem, 2026, 27, e202500920. DOI: /10.1002/cphc.202500920
Version of Record
Abstract
This work examines the effects on intrinsic energetics as the composition of finite (HCl)m(H2O)n cluster families containing at least one water molecule is changed at the molecular level, where m ≥ 2 and m + n = 4 − 6, and the associated (Cl−)x(H3O+)x(HCl)m−x(H2O)n−x clusters resulting from the dissociation of x HCl fragments via proton transfer (PT). They are collectively labeled m:n, and xPT indicates the degree of dissociation, from 0PT (no dissociation) up to 3PT. More than 1000 unique minima were identified via ωB97X-D/6-31++G(d,p) optimizations and frequency computations. Of those, nearly 500 lie within 5 kcal mol−1 of the corresponding lowest-energy minimum structure as determined by CCSD(T)-F12/haTZ-F12 single point energies: 25 for the 2:2 and 3:1 tetramers, 127 for the 2:3, 3:2, and 4:1 pentamers, and 333 for the 2:4, 3:3, 4:2, and 5:1 hexamers. In four of the nine m:n systems examined (2:2, 3:1, 4:1, 5:1), no low-energy minima exhibited PT, but the other five (2:3, 3:2, 2:4, 3:3, 4:2) have 1PT and 2PT structures with electronic energies near or below the lowest-energy 0PT configurations. In the 2:4, 3:3, and 4:2 hexamers, for example, at least one 1PT structure lies ≈4, 3, and 0.5 kcal mol−1 below the lowest-energy 0PT structures, respectively, based on CCSD(T)-F12 electronic energies.
Source Name
ChemPhysChem
Publication Date
Spring 4-25-2026
Volume
27
Page(s)
e202500920
Document Type
Citation
Citation Type
Article
Disciplines
Chemistry