Journal article

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

Abstract

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..

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Grants

Awarded by Australian Research Council


Funding Acknowledgements

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.