Synergistic Photochemistry of Alcohols Catalyzed by Plasmonic Nanoparticles and a Metal Complex

In photocatalytic schemes, it is common practice to employ a sacrificial agent for scavenging photogenerated holes and enhancing the yield and efficiency of electron harvesting. However, little attention is paid to the chemistry triggered by hole-mediated oxidation. Here, we trace the chemical fate of aliphatic alcohols used as hole scavengers in the photoinduced synthesis of Au nanoparticles. Under the action of visible light and the [AuCl4](-) precursor, the alcohol undergoes a sequence of reactions, including oxidation, C-C bond scission, and chlorination, to form a chloroalkane and a carbonyl compound. Mechanistic and parametric studies show that this atypical chemistry is activated by the Lewis-acidic metal center of [AuCl4](-) and enhanced by photoexcited carriers generated by interband excitation of Au nanoparticles. This work presents a unique example of interplay between a heterogeneous photocatalyst and a metal complex. Exploiting such synergy can be a route to new catalytic reactions.

Automated summary

This study investigates the chemistry triggered by aliphatic alcohols used as sacrificial agents in the photoinduced synthesis of Au nanoparticles. The results show that the Lewis-acidic metal center of the [AuCl4](-) complex activates atypical reactions, enhanced by the photoexcited carriers generated by the Au nanoparticles. This work presents a unique example of interplay between a heterogeneous photocatalyst and a metal complex, which may lead to new catalytic reactions.