The Tandem Photoredox Catalysis Mechanism of [Ir(ppy)(2)(dtb-bpy)]( ) Enabling Access to Energy Demanding Organic Substrates
Timothy U Connell, Catherine L Fraser, Milena L Czyz, Zoe M Smith, David J Hayne, Egan H Doeven, Johnny Agugiaro, David JD Wilson, Jacqui L Adcock, Andrew D Scully, Daniel E Gomez, Neil W Barnett, Anastasios Polyzos, Paul S Francis
Journal of the American Chemical Society | AMER CHEMICAL SOC | Published : 2019
We report the discovery of a tandem catalytic process to reduce energy demanding substrates, using the [Ir(ppy)2(dtb-bpy)]+ (1 + ) photocatalyst. The immediate products of photoinitiated electron transfer (PET) between 1 + and triethylamine (TEA) undergo subsequent reactions to generate a previously unknown, highly reducing species (2). Formation of 2 occurs via reduction and semisaturation of the ancillary dtb-bpy ligand, where the TEA radical cation serves as an effective hydrogen atom donor, confirmed by nuclear magnetic resonance, mass spectrometry, and deuterium labeling experiments. Steady-state an..View full abstract
Awarded by Australian Research Council
This work was funded by the Australian Research Council (DP160103046, FT140100514, IC170100020). AP acknowledges funding from the University of Melbourne and CSIRO joint Establishment Grant. We acknowledge generous allocations of computing from La Trobe University, Intersect, and NCI. The authors thank Ms. Lifen Chen (Deakin University) for assistance with obtaining low-temperature photoluminescence spectra. The authors would also like to thank Dr. Jo Cosgriff and Dr. Carl Braybook (CSIRO) for assistance with the NMR and ESI-MS experiments.