Assessing the Intrinsic Strengths of Ion–Solvent and Solvent–Solvent Interactions for Hydrated Mg2+ Clusters

Information resulting from a comprehensive investigation into the intrinsic strengths of hydrated divalent magnesium clusters is useful for elucidating role aqueous solvents on Mg2+ ion, which can be related to those in bulk solution. However, Mg–O and intermolecular hydrogen bond interactions ion have yet quantitatively measured. In this work, we investigated set 17 by means local vibrational mode force constants calculated at ωB97X-D/6-311++G(d,p) level theory, where nature ion–solvent solvent–solvent were interpreted topological electron density analysis natural population analysis. We found strength inner shell [Mg(H2O)n]2+ (n = 1–6) relate critical point bonds. From application secondary hydration 5–6) clusters, stronger observed correspond larger instances charge transfer between lp(O) orbitals unfilled valence Mg. As water molecules first second solvent increased, so did their bonds (HBs). Cumulative explicitly solvated Mg2+, having an outer shell, reveal CN 5, rather than 6, yield slightly more stable configurations some instances. cumulative stretching implicitly show six-coordinated cluster most stable. These results that such measures HBs offer effective way determining coordination number clusters.