Copper-Bridged Tetrakis(4-ethynylphenyl)ethene Aggregates with Photo-Regulated 1O2 and O2.- Generation for Selective Photocatalytic Aerobic Oxidation

Active species regulation is a key scientific issue that essentially determines the selectivity and activity of a photocatalyst. Herein, Cu-I-bridged tetrakis(4-ethynylphenyl)ethene aggregates (T4EPE-Cu) with photo-regulated O-1(2) and O-2(.-) generation were demonstrated for selective photocatalytic aerobic oxidation. In this system, transient photovoltage combined with the density functional theory calculations confirmed that Cu-alkynyl was the main oxygen activation site. The adsorbed O-2 tends to produce O-2(.-) because of the potential well effect of Cu-alkynyl under high-energy light excitation. But under low-energy light, O-2 tends to produce O-1(2) via resonance energy transfer with Cu-alkynyl. For alpha-terpinene oxidation, the ratios of O-1(2) products to O-2(.-) products can be controlled from 1.3 (380 nm) to 10.7 (600 nm). Furthermore, T4EPE-Cu exhibited ultrahigh photocatalytic performance for Glaser coupling and benzylamine oxidation, with a conversion and selectivity of over 99 %.

Automated summary

The Cu-I-bridged tetrakis(4-ethynylphenyl)ethene aggregates (T4EPE-Cu) demonstrated photo-regulated O-1(2) and O-2(.-) generation for selective photocatalytic aerobic oxidation, with Cu-alkynyl confirmed as the main oxygen activation site. The O-1(2) to O-2(.-) product ratios can be controlled in a range from 1.3 to 10.7, and T4EPE-Cu shows ultrahigh photocatalytic performance for Glaser coupling and benzylamine oxidation, with over 99 % conversion and selectivity.