The understanding of quantum correlations within catalysts is an active and advanced research field, absolutely necessary when attempting to describe all the relevant electronic factors in catalysis. In our previous research, we came to the conclusion that the most promising electronic interactions to improve the optimization of technological applications based on magnetic materials are quantum spin exchange interactions (QSEI), nonclassical orbital mechanisms that considerably reduce the Coulomb repulsion between electrons with the same spin. QSEI can stabilize open-shell orbital configurations with unpaired electrons in magnetic compositions. These indirect spin-potentials significantly influence and differentiate the catalytic properties of magnetic materials. As a rule of thumb, reaction kinetics (thus catalytic activity) generally increase when interatomic ferromagnetic (FM) interactions are dominant, while it sensibly decreases when antiferromagnetic (AFM) interactions prevail. The influence of magnetic patterns and spin-potentials can be easily spotted in several reactions, including the most important biocatalytic reactions like photosynthesis, for instance. Moreover, we add here the concept of quantum excitation interactions (QEXI) as a crucial factor to establish the band gap in materials and as a key factor to efficiently mediate electron transfer reactions. In the present Perspective, we offer a general conceptual overview, mainly based on our recent research, on the importance of strongly correlated electrons and their interactions during catalytic events. We present the physical principles and meanings behind quantum exchange in a way that facilitates a comprehensive understanding of the electronic interactions in catalysis from their quantum roots; we explore the issue via mathematical treatment as well as via intuitive visual space/time diagrams to expand the potential readership beyond the domain of physicists and quantum chemists.

The importance of discovering the true catalytically active species involved in photocatalytic systems allows for a better and more general understanding of photocatalytic processes, which eventually may help to improve their efficiency. Bi₂O₃ has been used as a heterogeneous photocatalyst and is able to catalyze several synthetically important visible-light-driven organic transformations. However, insight into the operative catalyst involved in the photocatalytic process is hitherto missing. Herein, we show through a combination of theoretical and experimental studies that the perceived heterogeneous photocatalysis with Bi₂O₃ in the presence of alkyl bromides involves a homogeneous Bi_nBr_m species, which is the true photocatalyst operative in the reaction. Hence, Bi₂O₃ can be regarded as a precatalyst which is slowly converted in an active homogeneous photocatalyst. This work can also be of importance to mechanistic studies involving other semiconductor-based photocatalytic processes.