Ion-Pair Reorganization Regulates Reactivity in Photoredox Catalysts

Earley, Justin D.; Zieleniewska, Anna; Ripberger, Hunter H.; Shin, Nick Y.; Lazorski, Megan S.; Mast, Zachary J.; Sayre, Hannah J.; McCusker, James K.; Scholes, Greg D.; Knowles, Robert R.; Reid, Obadiah G.; Rumbles, Garry

doi:10.1038/s41557-022-00911-6

Ion-Pair Reorganization Regulates Reactivity in Photoredox Catalysts

Journal Article · Thu Apr 14 04:00:00 EDT 2022 · Nature Chemistry

DOI:https://doi.org/10.1038/s41557-022-00911-6· OSTI ID:1865121

Earley, Justin D.; Zieleniewska, Anna; Ripberger, Hunter H.; Shin, Nick Y.; Lazorski, Megan S.; Mast, Zachary J.; Sayre, Hannah J.; McCusker, James K.; Scholes, Greg D.; Knowles, Robert R.; Reid, Obadiah G.;

Cyclometalated and polypyridyl complexes of d6 metals are promising photoredox catalysts, using light to drive reactions with high kinetic or thermodynamic barriers via the generation of reactive radical intermediates. However, while tuning of their redox potentials, absorption energy, excited-state lifetime and quantum yield are well-known criteria for modifying activity, other factors could be important. Here we show that dynamic ion-pair reorganization controls the reactivity of a photoredox catalyst, [Ir[dF(CF3)ppy]2(dtbpy)]X. Time-resolved dielectric-loss experiments show how counter-ion identity influences excited-state charge distribution, evincing large differences in both the ground- and excited-state dipole moment depending on whether X is a small associating anion (PF6-) that forms a contact-ion pair versus a large one that either dissociates or forms a solvent-separated pair (BArF4-). These differences correlate with the reactivity of the photocatalyst toward both reductive and oxidative electron transfer, amounting to a 4-fold change in selectivity toward oxidation versus reduction. These results suggest that ion pairing could be an underappreciated factor that modulates reactivity in ionic photoredox catalysts.

Research Organization:: National Renewable Energy Laboratory (NREL), Golden, CO (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)

DOE Contract Number:: AC36-08GO28308

OSTI ID:: 1865121

Report Number(s):: NREL/JA-5900-80913; MainId:78691; UUID:4da57d2c-2d41-4192-9e68-1e2356f17cfe; MainAdminID:64382

Journal Information:: Nature Chemistry, Journal Name: Nature Chemistry Journal Issue: 7 Vol. 14

Country of Publication:: United States

Language:: English

References (46)

Photofunctional triplet excited states of cyclometalated Ir(iii) complexes: beyond electroluminescence You, Youngmin; Nam, Wonwoo Chemical Society Reviews, Vol. 41, Issue 21 https://doi.org/10.1039/c2cs35171d	journal	January 2012
Conversion of Lignin Models by Photoredox Catalysis Zhang, Jian ChemSusChem, Vol. 11, Issue 18 https://doi.org/10.1002/cssc.201801370	journal	August 2018
Resolution and analysis of the components in dual emission of mixed-chelate/ortho-metalate complexes of iridium(III) Wilde, Ashley P.; King, Kevin A.; Watts, Richard J. The Journal of Physical Chemistry, Vol. 95, Issue 2 https://doi.org/10.1021/j100155a026	journal	January 1991
Optical and Thermal Electron Transfer in KCl: Tl ⁺ Crystals Tsuboi, Taiju Zeitschrift für Naturforschung A, Vol. 33, Issue 10 https://doi.org/10.1515/zna-1978-1005	journal	October 1978
The photophysics of photoredox catalysis: a roadmap for catalyst design Arias-Rotondo, Daniela M.; McCusker, James K. Chemical Society Reviews, Vol. 45, Issue 21 https://doi.org/10.1039/C6CS00526H	journal	January 2016
High-Throughput Screening and Automated Data-Driven Analysis of the Triplet Photophysical Properties of Structurally Diverse, Heteroleptic Iridium(III) Complexes DiLuzio, Stephen; Mdluli, Velabo; Connell, Timothy U. Journal of the American Chemical Society, Vol. 143, Issue 2 https://doi.org/10.1021/jacs.0c12290	journal	January 2021
Cross-Electrophile Coupling of Unactivated Alkyl Chlorides Sakai, Holt A.; Liu, Wei; Le, Chi “Chip” Journal of the American Chemical Society, Vol. 142, Issue 27 https://doi.org/10.1021/jacs.0c04812	journal	June 2020
Controlling Phosphorescence Color and Quantum Yields in Cationic Iridium Complexes: A Combined Experimental and Theoretical Study De Angelis, Filippo; Fantacci, Simona; Evans, Nicholas Inorganic Chemistry, Vol. 46, Issue 15 https://doi.org/10.1021/ic700435c	journal	June 2007
Synthetic Control of Excited-State Properties in Cyclometalated Ir(III) Complexes Using Ancillary Ligands Li, Jian; Djurovich, Peter I.; Alleyne, Bert D. Inorganic Chemistry, Vol. 44, Issue 6 https://doi.org/10.1021/ic048599h	journal	March 2005
General Strategy for Improving the Quantum Efficiency of Photoredox Hydroamidation Catalysis Ruccolo, Serge; Qin, Yangzhong; Schnedermann, Christoph Journal of the American Chemical Society, Vol. 140, Issue 44 https://doi.org/10.1021/jacs.8b09109	journal	October 2018
Manipulating the Excited States of Cyclometalated Iridium Complexes with β-Ketoiminate and β-Diketiminate Ligands Radwan, Yousf K.; Maity, Ayan; Teets, Thomas S. Inorganic Chemistry, Vol. 54, Issue 14 https://doi.org/10.1021/acs.inorgchem.5b01401	journal	July 2015
Light-Driven Depolymerization of Native Lignin Enabled by Proton-Coupled Electron Transfer Nguyen, Suong T.; Murray, Philip R. D.; Knowles, Robert R. ACS Catalysis, Vol. 10, Issue 1 https://doi.org/10.1021/acscatal.9b04813	journal	November 2019
Urea as a Redox-Active Directing Group under Asymmetric Photocatalysis of Iridium-Chiral Borate Ion Pairs Uraguchi, Daisuke; Kimura, Yuto; Ueoka, Fumito Journal of the American Chemical Society, Vol. 142, Issue 46 https://doi.org/10.1021/jacs.0c09468	journal	November 2020
Enantioselective [2+2] Cycloadditions of Cinnamate Esters: Generalizing Lewis Acid Catalysis of Triplet Energy Transfer Daub, Mary Elisabeth; Jung, Hoimin; Lee, Byung Joo Journal of the American Chemical Society, Vol. 141, Issue 24 https://doi.org/10.1021/jacs.9b04643	journal	April 2019
Ion Pairing Marcus, Yizhak; Hefter, Glenn Chemical Reviews, Vol. 106, Issue 11 https://doi.org/10.1021/cr040087x	journal	November 2006
Ion Pairing in Transition-Metal Organometallic Chemistry Macchioni, Alceo Chemical Reviews, Vol. 105, Issue 6 https://doi.org/10.1021/cr0300439	journal	June 2005
Theoretical Studies of the Ground and Excited Electronic States in Cyclometalated Phenylpyridine Ir(III) Complexes Using Density Functional Theory Hay, P. Jeffrey The Journal of Physical Chemistry A, Vol. 106, Issue 8 https://doi.org/10.1021/jp013949w	journal	February 2002
Accelerated Luminophore Discovery through Combinatorial Synthesis Lowry, Michael S.; Hudson, William R.; Pascal, Robert A. Journal of the American Chemical Society, Vol. 126, Issue 43 https://doi.org/10.1021/ja047156+	journal	October 2004
Discovery and Elucidation of Counteranion Dependence in Photoredox Catalysis Farney, Elliot P.; Chapman, Steven J.; Swords, Wesley B. Journal of the American Chemical Society, Vol. 141, Issue 15 https://doi.org/10.1021/jacs.9b01885	journal	March 2019
"Second-sphere" photochemistry and photophysics of coordination compounds Balzani, Vincenzo; Sabbatini, Nanda; Scandola, Franco Chemical Reviews, Vol. 86, Issue 2 https://doi.org/10.1021/cr00072a002	journal	April 1986
Synthetically Tailored Excited States: Phosphorescent, Cyclometalated Iridium(III) Complexes and Their Applications Lowry, Michael S.; Bernhard, Stefan Chemistry - A European Journal, Vol. 12, Issue 31 https://doi.org/10.1002/chem.200600618	journal	October 2006
Ultrafast excited state dynamics of iridium( iii ) complexes and their changes upon immobilisation onto titanium dioxide layers Tschierlei, Stefanie; Neubauer, Antje; Rockstroh, Nils Physical Chemistry Chemical Physics, Vol. 18, Issue 16 https://doi.org/10.1039/C6CP00343E	journal	January 2016
Chloride Ion-Pairing with Ru(II) Polypyridyl Compounds in Dichloromethane Ward, William M.; Farnum, Byron H.; Siegler, Maxime The Journal of Physical Chemistry A, Vol. 117, Issue 36 https://doi.org/10.1021/jp404838z	journal	August 2013
Visible light photocatalytic acyldifluoroalkylation of unactivated alkenes for the direct synthesis of gem -difluorinated ketones Zhou, Yulu; Xiong, Zhimin; Qiu, Jiayan Organic Chemistry Frontiers, Vol. 6, Issue 7 https://doi.org/10.1039/C9QO00136K	journal	January 2019
Contemporary Issues in Electron Transfer Research Barbara, Paul F.; Meyer, Thomas J.; Ratner, Mark A. The Journal of Physical Chemistry, Vol. 100, Issue 31 https://doi.org/10.1021/jp9605663	journal	January 1996
A study of the dielectric relaxation behavior of photoinduced transient species Fessenden, Richard W.; Hitachi, A. The Journal of Physical Chemistry, Vol. 91, Issue 12 https://doi.org/10.1021/j100296a070	journal	June 1987
Excited-State Properties of Heteroleptic Iridium(III) Complexes Bearing Aromatic Hydrocarbons with Extended Cores Spaenig, Fabian; Olivier, Jean-Hubert; Prusakova, Valentina Inorganic Chemistry, Vol. 50, Issue 21 https://doi.org/10.1021/ic201397v	journal	September 2011
Direct Spectroscopic Observation of Interligand Energy Transfer in Cyclometalated Heteroleptic Iridium(III) Complexes: A Strategy for Phosphorescence Color Tuning and White Light Generation You, Youngmin; Kim, Kil Suk; Ahn, Tae Kyu The Journal of Physical Chemistry C, Vol. 111, Issue 10 https://doi.org/10.1021/jp0702550	journal	February 2007
Metal centered ligand field excited states: Their roles in the design and performance of transition metal based photochemical molecular devices Wagenknecht, Paul S.; Ford, Peter C. Coordination Chemistry Reviews, Vol. 255, Issue 5-6 https://doi.org/10.1016/j.ccr.2010.11.016	journal	March 2011
The influence of environmental effects on excited-state lifetimes. The effect of ion pairing on metal-to-ligand charge transfer excited states Vining, William J.; Caspar, Jonathan V.; Meyer, Thomas J. The Journal of Physical Chemistry, Vol. 89, Issue 7 https://doi.org/10.1021/j100253a010	journal	March 1985
Electronic and Medium Effects on the Rate of Arene C−H Bond Activation by Cationic Ir(III) Complexes Tellers, David M.; Yung, Cathleen M.; Arndtsen, Bruce A. Journal of the American Chemical Society, Vol. 124, Issue 7 https://doi.org/10.1021/ja011809u	journal	February 2002
Highly Fluorinated Ir(III)–2,2′:6′,2″-Terpyridine–Phenylpyridine–X Complexes via Selective C–F Activation: Robust Photocatalysts for Solar Fuel Generation and Photoredox Catalysis Porras, Jonathan A.; Mills, Isaac N.; Transue, Wesley J. Journal of the American Chemical Society, Vol. 138, Issue 30 https://doi.org/10.1021/jacs.6b03246	journal	July 2016
Mechanism of halide-induced disproportionation of M(CO)3(PCy3)2+ 17-electron radicals (M = iron, ruthenium, osmium). Periodic trends on reactivity and the role of ion pairs Song, Lin; Trogler, William C. Journal of the American Chemical Society, Vol. 114, Issue 9 https://doi.org/10.1021/ja00035a029	journal	April 1992
Solvent effects on metal-to-ligand charge-transfer bands in ortho-metalated complexes of iridium(III): estimates of transition dipole moments Wilde, A. P.; Watts, Richard J. The Journal of Physical Chemistry, Vol. 95, Issue 2 https://doi.org/10.1021/j100155a025	journal	January 1991
Dual emission from an ortho-metalated iridium(III) complex King, K. A.; Watts, R. J. Journal of the American Chemical Society, Vol. 109, Issue 5 https://doi.org/10.1021/ja00239a060	journal	March 1987
Single-Layer Electroluminescent Devices and Photoinduced Hydrogen Production from an Ionic Iridium(III) Complex Lowry, Michael S.; Goldsmith, Jonas I.; Slinker, Jason D. Chemistry of Materials, Vol. 17, Issue 23 https://doi.org/10.1021/cm051312+	journal	October 2005
C–H Alkylation via Multisite-Proton-Coupled Electron Transfer of an Aliphatic C–H Bond Morton, Carla M.; Zhu, Qilei; Ripberger, Hunter Journal of the American Chemical Society, Vol. 141, Issue 33 https://doi.org/10.1021/jacs.9b06834	journal	July 2019
Static and Dynamic Quenching of Ru(II) Polypyridyl Excited States by Iodide Marton, Andras; Clark, Christopher C.; Srinivasan, Ramya Inorganic Chemistry, Vol. 45, Issue 1 https://doi.org/10.1021/ic051467j	journal	December 2005
A Metallaphotoredox Strategy for the Cross‐Electrophile Coupling of α‐Chloro Carbonyls with Aryl Halides Chen, Tiffany Q.; MacMillan, David W. C. Angewandte Chemie International Edition, Vol. 58, Issue 41 https://doi.org/10.1002/anie.201909072	journal	September 2019
Dielectric-loss spectroscopy development and iridium photoredox catalyst ion pairing Earley, Justin; Zieleniewska, Ania; Shin, Nick Zenodo https://doi.org/10.5281/zenodo.5899758	dataset	January 2022
An Anion-Dependent Switch in Selectivity Results from a Change of C−H Activation Mechanism in the Reaction of an Imidazolium Salt with IrH ₅ (PPh ₃ ) ₂ Appelhans, Leah N.; Zuccaccia, Daniele; Kovacevic, Anes Journal of the American Chemical Society, Vol. 127, Issue 46 https://doi.org/10.1021/ja055317j	journal	November 2005
Efficient Yellow Electroluminescence from a Single Layer of a Cyclometalated Iridium Complex Slinker, Jason D.; Gorodetsky, Alon A.; Lowry, Michael S. Journal of the American Chemical Society, Vol. 126, Issue 9 https://doi.org/10.1021/ja0345221	journal	March 2004
Photoinduced Intramolecular Charge Separation in Donor/Acceptor-Substituted Bicyclohexylidene and Bicyclohexyl Hoogesteger, Frans J.; van Walree, Cornelis A.; Jenneskens, Leonardus W. Chemistry - A European Journal, Vol. 6, Issue 16 https://doi.org/10.1002/1521-3765(20000818)6:16<2948::AID-CHEM2948>3.0.CO;2-0	journal	August 2000
Dynamics of the Excited States of [Ir(ppy) ₂ bpy] ⁺ with Triple Phosphorescence Wu, Shih-Hsiang; Ling, Jung-Wei; Lai, Szu-Hsueh The Journal of Physical Chemistry A, Vol. 114, Issue 38 https://doi.org/10.1021/jp102264q	journal	September 2010
The search for larger and more weakly coordinating anions Strauss, Steven H. Chemical Reviews, Vol. 93, Issue 3 https://doi.org/10.1021/cr00019a005	journal	May 1993
Redox Active Ion-Paired Excited States Undergo Dynamic Electron Transfer Troian-Gautier, Ludovic; Beauvilliers, Evan E.; Swords, Wesley B. Journal of the American Chemical Society, Vol. 138, Issue 51 https://doi.org/10.1021/jacs.6b11337	journal	December 2016

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Ion-Pair Reorganization Regulates Reactivity in Photoredox Catalysts

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