Carbon dioxide interaction with isolated imidazole or attached on gold clusters and surface: competition between σ H-bond and π stacking interaction

Abstract

Using first principle methodologies, we investigate the subtle competition between σ H-bond and π stacking interaction between CO₂ and imidazole either isolated, adsorbed on a gold cluster or adsorbed on a gold surface. These computations are performed using MP2 as well as dispersion corrected density functional theory (DFT) techniques. Our results show that the CO₂ interaction goes from π-type stacking into σ-type when CO₂ interacts with isolated imidazole and Au clusters or surface. The balance between both types of interactions is found when an imidazole is attached to a Au₂₀ gold cluster. Thus, the present study has great significance in understanding and controlling the structures of weakly-bound molecular systems and materials, where hydrogen bonding and van der Waals interactions are competing. The applications are in the fields of the control of CO₂ capture and scattering, catalysis and bio- and nanotechnologies.