Incorporation of photocatalytic Pt(II) complexes into imine-based layered covalent organic frameworks (COFs) through monomer truncation strategy

Abstract

A new photoactive Pt (II) hydroxyquinoline complex has been covalently linked into the structure of an imine-based layered covalent organic framework (COF) through the monomer truncation strategy. Such strategy allows the incorporation of molecular fragments with only one functional group able to condensate into the imine-framework. The photocatalytic activity of the resulting Pt@COF has been applied to the oxidation of sulfides to sulfoxides, obtaining excellent results for all the studied cases, and showing that this reaction goes through both photoredox and energy transfer processes. The results obtained showed a great enhancement of the catalytic activity (up to 25000 turnover number, TON), stability and a significant decrease on the reaction times, as a consequence of immobilization and isolation of Pt(II) centers into the organic framework. In addition, Pt@COF has been proved to be an excellent heterogeneous photocatalyst also in exclusive photoredox processes, reaching 7500 TON in hydrodebromination reactions