Tuning the adsorption interactions of imidazole derivatives with specific metal cations

In this work, we report a computational study of the interactions between metal cations and imidazole derivatives in the gas phase. We first performed a systematic assessment of various density functionals and basis sets for predicting the binding energies between metal cations and the imidazoles. We find that the M11L functional in combination with the 6-311++G(d,p) basis set provides the best compromise between accuracy and computational cost with our metal···imidazole complexes. We then evaluated the binding of a series of metal cations, including Li(+), Na(+), K(+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Ba(2+), Hg(2+), and Pb(2+), with several substituted imidazole derivatives. We find that electron-donating groups increase the metal-binding energy, whereas electron-withdrawing groups decrease the metal-binding energy. Furthermore, the binding energy trends can be rationalized by the hardness of the metal cations and imidazole derivatives, providing a quick way to estimate the metal···imidazole binding strength. This insight can enable efficient screening protocols for identifying effective imidazole-based solvents and membranes for metal adsorption and provide a framework for understanding metal···imidazole interactions in biological systems.