Oxygen Reduction Activity of B←N‐Containing Organic Molecule Affected by Asymmetric Regulation

Abstract Organic molecular catalysts have received great attention as they have the merits of well‐controlled molecular structures for the development of catalytic chemistry. Herein, the electronic distribution of active sites is regulated by asymmetrically introducing S‐heterocycle on one side of the molecular core. As a result, the asymmetric as‐PYT and as‐BNT show higher oxygen reduction performance than their symmetric counterparts without (s‐PY, s‐PY2T) or with two S‐heterocycle units (s‐BN, s‐BN2T). Density functional theory calculations reveal that the carbon atoms (site–12) at symmetric s‐BN and s‐BN2T are the catalytic active sites, while for asymmetric as‐BNT, it has changed to amino‐N atom (site‐14). Due to the non‐uniform charge distribution and increased dipole moment of as‐BNT caused by asymmetric molecular configuration, the kinetics of catalytic reaction has changed significantly. The catalytically active sites of specific N atoms are further verified experimentally and theoretically by using sterically hindered phenyl groups. This work provides a simple but efficient method to design metal‐free oxygen reduction electrocatalysts.