Nature determines selectivity and activity in biological reactive centers, based on single metal atom macrocycles, by properly tuning the primary coordination sphere and the surrounding protein scaffold. In a biomimetic approach, we show that activation of carbon dioxide at a 2D crystal of phthalocyanines supported by graphene can be controlled by chemical tuning of the position of the Dirac cones of the support through oxygen adsorption. The room temperature stabilization of the CO2–Fe chemical bond, detected in situ and confirmed by computational density-functional theory simulations, is obtained by governing the charge transfer across the graphene–metallorganic layer interface upon oxidation of graphene at close-to-ambient conditions. In this way, we can turn a weakly binding site into a strong one in an artificial structure that mimics many features of complex biological systems.

We show that, for the formation of a metallorganic monolayer, it is possible to artificially divert from substrate- to laterally-driven self-assembly mechanisms by properly tailoring the corrugation of the potential energy surface of the growth template. By exploiting the capability of an ultrathin alumina film to host metallic nanoparticle seeds, we tune the symmetry of a iron phthalocyanine (FePc) two-dimensional crystal, thus showing that it is possible to switch from trans to lateral dominating interactions in the controlled growth of an organic/inorganic heterostack. Finally, by selecting the size of the metallic clusters, we can also control the FePc-metal interaction strength.