Adsorption and reaction of 2-methylbenzimidazole molecules on a partially oxidized Cu(110) surface.

This article focuses on the adsorption behavior and surface reactions of 2-methylbenzimidazole (MBI) molecules, structurally related to N-heterocyclic carbenes (NHCs), on partially oxidized Cu(110) surfaces (CuO/Cu(110)). Using scanning tunneling microscopy (STM) and non-contact atomic force microscopy (nc-AFM), the study reveals that MBI molecules induce reduction of the CuO layer through dehydrogenation involving N–H bond cleavage, releasing Cu adatoms that aggregate into islands. Before annealing, molecules predominantly adopt a flat-lying configuration on CuO/Cu(110), while annealing at 378 K leads to tilted flat-lying adsorption on CuO regions and upright configurations forming double chains on bare copper areas, suggesting coordination bonding with Cu atoms. Comparative experiments on bare Cu(110) surfaces confirm that molecular deprotonation and Cu adatom coordination drive these adsorption and surface modification processes, providing insights into metal surface functionalization and oxide reduction mechanisms by NHC-related molecules.