Characterizing and Contrasting Structural Proton Transport Mechanisms in Azole Hydrogen Bond Networks Using <i>Ab Initio</i> Molecular Dynamics

Imidazole and 1,2,3-triazole are promising hydrogen-bonded heterocycles that conduct protons via a structural mechanism whose derivatives present in systems ranging from biological proton channels to exchange membrane fuel cells. Here, we leverage multiple time-stepping perform ab initio molecular dynamics of imidazole at the nanosecond time scale. We show despite close similarities these compounds, their diffusion constants vary by over an order magnitude. Our simulations reveal reasons for differences constants, which range degree chain linearity effect central nitrogen atom on transport. In particular, uncover evidence two “blocking” mechanisms 1,2,3-triazole, where covalent hydrogen bonds formed limit mobility protons. thus provide insights into origins experimentally observed 10-fold difference conductivity.