Mapping the Relationship of the Dynamic Active Site and the Activation Barrier for Cross-Coupling Reactions on Geminal-Cu Catalyst

In this work, we elaborate on the configurations, electronic properties, and cross-coupling reaction mechanisms of several (hetero) aryl halides and X-based (X = N, C, O, S) nucleophiles coadsorbed on a novel geminal-Cu sites deposited on the polymeric carbon nitride (Cu_g/PCN). All reactants undergo an exothermic dynamic bridge-coupling process accompanied by reconstruction of the Cu-Cu sites. The activation barriers of the reaction, following the order of C-N > C-C > C-O > C-S, are positively associated with the degree of dynamic contraction of the Cu-Cu bond distance during the couplings, which aligns well with the experimental conditions. Overall, because of the quantum primogenic effect, the dynamic change of the geminal-Cu distance acts as a driving force, enabling the efficient coupling reactions on the Cu_g/PCN. Unraveling the structure-activity relationship on Cu_g/PCN facilitates the development of cross-coupling catalysis.