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Shillito GE, Preston D, Crowley JD, Wagner P, Harris SJ, Gordon KC, Kupfer S. Controlling Excited State Localization in Bichromophoric Photosensitizers via the Bridging Group. Inorg Chem 2024; 63:4947-4956. [PMID: 38437618 PMCID: PMC10951951 DOI: 10.1021/acs.inorgchem.3c04110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/18/2024] [Accepted: 01/30/2024] [Indexed: 03/06/2024]
Abstract
A series of photosensitizers comprised of both an inorganic and an organic chromophore are investigated in a joint synthetic, spectroscopic, and theoretical study. This bichromophoric design strategy provides a means by which to significantly increase the excited state lifetime by isolating the excited state away from the metal center following intersystem crossing. A variable bridging group is incorporated between the donor and acceptor units of the organic chromophore, and its influence on the excited state properties is explored. The Franck-Condon (FC) photophysics and subsequent excited state relaxation pathways are investigated with a suite of steady-state and time-resolved spectroscopic techniques in combination with scalar-relativistic quantum chemical calculations. It is demonstrated that the presence of an electronically conducting bridge that facilitates donor-acceptor communication is vital to generate long-lived (32 to 45 μs), charge-separated states with organic character. In contrast, when an insulating 1,2,3-triazole bridge is used, the excited state properties are dominated by the inorganic chromophore, with a notably shorter lifetime of 60 ns. This method of extending the lifetime of a molecular photosensitizer is, therefore, of interest for a range of molecular electronic devices and photophysical applications.
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Affiliation(s)
- Georgina E. Shillito
- Institute
of Physical Chemistry, Friedrich Schiller
University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Dan Preston
- Research
School of Chemistry, Australian National
University, Canberra, ACT 2600, Australia
| | - James D. Crowley
- Department
of Chemistry, University of Otago, 362 Leith Street, Dunedin 9016, New Zealand
- MacDiarmid
Institute for Advanced Materials and Nanotechnology, Wellington, 6012, New Zealand
| | - Pawel Wagner
- University
of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia
| | - Samuel J. Harris
- Department
of Chemistry, University of Otago, 362 Leith Street, Dunedin 9016, New Zealand
- MacDiarmid
Institute for Advanced Materials and Nanotechnology, Wellington, 6012, New Zealand
| | - Keith C. Gordon
- Department
of Chemistry, University of Otago, 362 Leith Street, Dunedin 9016, New Zealand
- MacDiarmid
Institute for Advanced Materials and Nanotechnology, Wellington, 6012, New Zealand
| | - Stephan Kupfer
- Institute
of Physical Chemistry, Friedrich Schiller
University Jena, Helmholtzweg 4, 07743 Jena, Germany
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Zedler L, Kupfer S, Schmidt H, Dietzek-Ivanšić B. Oxidation-state sensitive light-induced dynamics of Ruthenium-4H-Imidazole complexes. Chemistry 2023:e202303079. [PMID: 38131166 DOI: 10.1002/chem.202303079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 12/20/2023] [Accepted: 12/22/2023] [Indexed: 12/23/2023]
Abstract
Oxidized molecular states are key intermediates in photo-induced redox reactions, e. g., intermolecular charge transfer between photosensitizer and catalyst in photoredox catalysis. The stability and longevity of the oxidized photosensitizer is an important factor in optimizing the respective light-driven reaction pathways. In this work the oxidized states of ruthenium(II)-4H-imidazole dyes are studied. The ruthenium complexes constitute benchmark photosensitizers in solar energy interconversion processes with exceptional chemical stability, strong visible light absorption, and favourable redox properties. To rationalize the light-induced reaction in the oxidized ruthenium(III) systems, we combine UV-vis absorption, resonance Raman, and transient absorption spectroelectrochemistry (SEC) with time-dependent density functional theory (TDDFT) calculations. Three complexes are compared, which vary with respect to their coordination environment, i. e., combining an 4H-imidazole with either 2,2'-bipyridine (bpy) or 2,2';6'2"-terpyridine (tpy) coligands, and chloride or isothiocyanate ligands. While all oxidized complexes have similar steady state absorption properties, their excited state kinetics differ significantly; the study thus opens the doorway to study the light-driven reactivity of oxidized molecular intermediates in intermolecular charge transfer cascades.
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Affiliation(s)
- Linda Zedler
- Functional Interfaces, Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | - Stephan Kupfer
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Heiner Schmidt
- Functional Interfaces, Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745, Jena, Germany
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Benjamin Dietzek-Ivanšić
- Functional Interfaces, Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745, Jena, Germany
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
- Jena Center for Soft Matter, Friedrich Schiller University Jena, Philosophenweg 7, 07743, Jena, Germany
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Zedler L, Wintergerst P, Mengele AK, Müller C, Li C, Dietzek-Ivanšić B, Rau S. Outpacing conventional nicotinamide hydrogenation catalysis by a strongly communicating heterodinuclear photocatalyst. Nat Commun 2022; 13:2538. [PMID: 35534473 PMCID: PMC9085789 DOI: 10.1038/s41467-022-30147-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 04/14/2022] [Indexed: 11/30/2022] Open
Abstract
Unequivocal assignment of rate-limiting steps in supramolecular photocatalysts is of utmost importance to rationally optimize photocatalytic activity. By spectroscopic and catalytic analysis of a series of three structurally similar [(tbbpy)2Ru-BL-Rh(Cp*)Cl]3+ photocatalysts just differing in the central part (alkynyl, triazole or phenazine) of the bridging ligand (BL) we are able to derive design strategies for improved photocatalytic activity of this class of compounds (tbbpy = 4,4´-tert-butyl-2,2´-bipyridine, Cp* = pentamethylcyclopentadienyl). Most importantly, not the rate of the transfer of the first electron towards the RhIII center but rather the rate at which a two-fold reduced RhI species is generated can directly be correlated with the observed photocatalytic formation of NADH from NAD+. Interestingly, the complex which exhibits the fastest intramolecular electron transfer kinetics for the first electron is not the one that allows the fastest photocatalysis. With the photocatalytically most efficient alkynyl linked system, it is even possible to overcome the rate of thermal NADH formation by avoiding the rate-determining β-hydride elimination step. Moreover, for this photocatalyst loss of the alkynyl functionality under photocatalytic conditions is identified as an important deactivation pathway.
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Affiliation(s)
- Linda Zedler
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
- Leibniz Institute of Photonic Technology Jena, Department Functional Interfaces, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | - Pascal Wintergerst
- Institute of Inorganic Chemistry I, Materials and Catalysis, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Alexander K Mengele
- Institute of Inorganic Chemistry I, Materials and Catalysis, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Carolin Müller
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
- Leibniz Institute of Photonic Technology Jena, Department Functional Interfaces, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | - Chunyu Li
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
- Leibniz Institute of Photonic Technology Jena, Department Functional Interfaces, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | - Benjamin Dietzek-Ivanšić
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.
- Leibniz Institute of Photonic Technology Jena, Department Functional Interfaces, Albert-Einstein-Straße 9, 07745, Jena, Germany.
- Center for Energy and Environmental Chemistry Jena (CEEC Jena), Philosophenweg 7a, 07743, Jena, Germany.
| | - Sven Rau
- Institute of Inorganic Chemistry I, Materials and Catalysis, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
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Darvasiová D, Šoral M, Puškárová I, Dvoranová D, Vénosová B, Bučinský L, Zalibera M, Dujnič V, Dobrov A, Schwalbe M, Arion VB, Rapta P. Spectroelectrochemical, photochemical and theoretical study of octaazamacrocyclic nickel(II) complexes exhibiting unusual solvent-dependent deprotonation of methylene group. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.135006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Sterically induced distortions of nickel(II) porphyrins – Comprehensive investigation by DFT calculations and resonance Raman spectroscopy. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2017.12.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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