Atmospheric implications of hydrogen bonding between methanesulfonic acid and 12 kinds of N-containing compounds

The hydrogen bonding interactions between methanesulfonic acid (MSA) and NH_x compounds, such as ammonia (A), alkylamines (aNH_x), and cyclic amino compounds (cNH_x), were investigated using density functional theory, atoms in molecules, localized molecular orbitals-based energy decomposition analysis, and atmospheric clusters dynamic code methods. The results revealed that these dimers exhibit hydrogen bonds by SOH⋯N interactions. MSA–cNH_x dimers showed higher binding energies compared to MSA–aNH_x/A dimers. Topological analysis using AIM confirmed the presence of hydrogen bonding in these dimers by ρ(r) and ∇²ρ(r). The results of IRI indicate that there are different strength types of hydrogen bonding interactions in these dimers. LMO–EDA highlighted electrostatic interactions as the main attractive force, particularly in MSA–cNH_x dimers. ACDC results showed a low evaporation rate for MSA–cNH_x dimers compared to others. These findings suggest that MSA plays a crucial role in NPF events, and MSA–cNH_x clusters could potentially act as nucleation nuclei in the atmosphere.