This article provides general guidelines, which are used to design photocatalytic organic transformations using graphitic carbon nitrides. It includes discussion of the local chemical structure of carbon nitride excited state, its redox potentials and the redox potentials of the reagents, and the chemical reactivity of the open-shell intermediates.

Abstract

Graphitic carbon nitride semiconductors are inexpensive and reusable photocatalysts, which are actively studied in organic synthesis. Successful design of photocatalytic reactions is based on the next considerations. i) Thermodynamic feasibility of photoinduced processes, which involve transfer of electrons or electron-proton couples. ii) Redox activity of reagents. iii) Reactivity of the open-shell intermediates generated from the reagents. Herein, we summarize current understanding of how local chemical structure of graphitic carbon nitrides and their redox potentials are used to design photocatalytic reactions. This work intends to serve as a guideline for materials scientists, who are willing to apply their carbon nitride semiconductors in reactions involving organic substrates, and for organic chemists, who are interested to dive into heterogeneous carbon nitride photocatalysis.