Dr. Joshua P. Barham
Title: Aggregation matters: diverting mechanisms in synthetic photocatalytic and photoelectrochemical reactions.
Speaker: Dr. Joshua P. Barham.
Institution: University of Strathclyde, United Kingdom.
When: 10:00 CET, Friday, September 5th, 2025.
Place: Sala de Grados, Module 8, Faculty of Science, Universidad Autónoma de Madrid.
Since the turn of the 21st century, chemists increasingly take inspiration from natural photosynthesis, driving the synthesis of high-value organic molecules with visible light-powered catalytic redox processes. However,
the scope of applications is constrained by i) the limited energy of visible light photons[1a] and ii) typical photocatalysts being unable to harness the full energy of the photon, due to rapid excited state deactivations. Synthetic Photoelectrochemistry is achieving new frontiers of reactivity and selectivity in single electron transfer-driven organic synthesis.[1b] This talk exemplifies how catalysts harnessing a combination of electrochemical and photonic energies achieve record-breaking redox processes.[2] With catalytic mechanisms a topic of current debate,[3] we find the key prerequisite for successful reactivity and high chemoselectivity are non-covalent preassemblies (aggregates) of the photoactive species and target substrate prior to photoexcitation.[2+3c,d] Aggregation effects of photocatalysts/reactants are gaining importance in contemporary synthetic photochemistry[5] and other examples from our lab will be discussed.
References
1. (a) JPB,* B. König, ACIE 2020, 59, 11732; (b) S. Wu, J. Kaur, T. A. Karl, X. Tian, JPB,* ACIE 2022, 61, e202107811.
2. (a) H. Kim, H. Kim, T. H. Lambert,* S. Lin,* JACS 2020, 142, 2087; (b) N. G. W. Cowper, C. P. Chernowsky, O. P. Williams, Z. K. Wickens,* JACS 2020, 142, 2093-2099; (c) S. Wu, J. Žurauskas, M. Domański, P. Hitzfeld, V. Butera, D. J. Scott, J. Rehbein, A. Kumar, E. Thyrhaug, J. Hauer, JPB,* Org. Chem. Front. 2021, 8, 1132; (d) X. Tian, T. A. Karl, S. Reiter, S. Yakubov, R. de Vivie-Riedle, B. König,* JPB,* ACIE 2021, 60, 20817.
3. (a) A. J. Rieth, M. I. Gonzalez, B. Kudisch, M. Nava, D. G. Nocera,* JACS. 2021, 143, 14352; (b) D. Y. Jeong, D. S. Lee, H. L. Lee, S. Nah, J. Y. Lee,* E. J. Cho,* Y. You,* ACS Catal. 2022, 12, 6047; (c) A. Kumar, P. Malecvich, L. Mewes, S. Wu, JPB, J. Hauer,* J. Phys. Chem. 2023, 158, 144201; (d) S. Horsewill, G. Hierlmeier, Z. Farasat, JPB, D. J. Scott,* ACS Catal. 2023, 13, 9392; (e) L. Wylie, JPB, B. Kirchner, ChemPhysChem 2024, 24, e202300470.
4. (a) M. Mandigma, J. Kaur, JPB,* ChemCatChem 2023, 11, e202201542; (b) M. Lepori, S. Schmid, JPB,* Beilstein J. Org. Chem. 2023, 19, 1055.
5. (a) S. Yakubov, W. Stockerl, X. Tian, A. Shahin, M. Mandigma, R. M. Gschwind, JPB,* Chem. Sci. 2022, 13, 14041; (b) S. Yakubov, B. Deuth, W. da Silva, R. M. Gschwind,* JPB* ChemSusChem 2024, 17, e202401057; (c) M. Mandigma, J. Žurauskas, C. I. MacGregor, L. J. Edwards, A. Shahin, L. d’Heureuse, P. Yip, D. J. S. Birch, T. Gruber, J. Heilmann, M. P. John, JPB,* Chem. Sci. 2022, 13, 1912. (d) J. Žurauskas, S. Boháčová, S. Wu, V. Butera, S. Schmid, M. Domański, T. Slanina, JPB,* ACIE 2023, 62, e202307550.
