1
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Jordan R, Maisuls I, Nair SS, Dietzek-Ivanšić B, Strassert CA, Klein A. Enhanced luminescence properties through heavy ancillary ligands in [Pt(C^N^C)(L)] complexes, L = AsPh 3 and SbPh 3. Dalton Trans 2023. [PMID: 38013458 DOI: 10.1039/d3dt03225f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
In the frame of our research aiming to develop efficient triplet-emitting materials, we are exploring the concept of introducing additional heavy atoms into cyclometalated transition metal complexes to enhance intersystem-crossing (ISC) and thus triplet emission through increased spin-orbit coupling (SOC). In an in-depth proof-of-principle study we investigated the double cyclometalated Pt(II) complexes [Pt(C^N^C)(PnPh3)] (HC^N^CH = 2,6-diphenyl-pyridine (H2dpp) or dibenzoacridine (H2dba); Pn = pnictogen atoms P, As, Sb, or Bi) through a combined experimental and theoretical approach. The derivatives containing Pn = P, As, and Sb were synthesised and characterised comprehensively using single crystal X-ray diffraction (scXRD), UV-vis absorption and emission spectroscopy, transient absorption (TA) spectroscopy and cyclic voltammetry (CV). Across the series P < As < Sb, a red-shift is observed concerning absorption and emission maxima as well as optical and electrochemical HOMO-LUMO gaps. Increased photoluminescence quantum yields ΦL and radiative rates kr from mixed metal-to-ligand charge transfer (MLCT)/ligand centred (LC) triplet states are observed for the heavier homologues. Transient absorption spectroscopy showed processes in the ps range that were assigned to the population of the T1 state by ISC. The heavy PnPh3 ancillary ligands are found to enhance the emission efficiency due to both higher Pt-Pn bond strength and stronger SOC related to increased MLCT character of the excited states. The experimental findings are mirrored in hybrid (TD-)DFT calculations. This allowed for extrapolation to the rather elusive Bi derivatives, which were synthetically not accessible. This shortcoming is attributed to the transmetalation of phenyl groups from BiPh3 to Pt, as supported by experimental NMR/MS as well as DFT studies.
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Affiliation(s)
- Rose Jordan
- University of Cologne, Faculty for Mathematics and Natural Sciences, Department of Chemistry, Institute for Inorganic Chemistry, Greinstrasse 6, D-50939 Köln, Germany.
| | - Iván Maisuls
- Universität Münster, Institut für Anorganische und Analytische Chemie, CiMIC, CeNTech, Heisenbergstraße 11, D-48149 Münster, Germany.
| | - Shruthi S Nair
- Friedrich Schiller University Jena, Institute for Physical Chemistry (IPC), Helmholtzweg 4, 07743 Jena, Germany.
- Leibniz Institute for Photonic Technologies Jena (IPHT), Research Department Functional Interfaces, Albert-Einstein-Str. 9, 07745 Jena, Germany.
| | - Benjamin Dietzek-Ivanšić
- Friedrich Schiller University Jena, Institute for Physical Chemistry (IPC), Helmholtzweg 4, 07743 Jena, Germany.
- Leibniz Institute for Photonic Technologies Jena (IPHT), Research Department Functional Interfaces, Albert-Einstein-Str. 9, 07745 Jena, Germany.
| | - Cristian A Strassert
- Universität Münster, Institut für Anorganische und Analytische Chemie, CiMIC, CeNTech, Heisenbergstraße 11, D-48149 Münster, Germany.
| | - Axel Klein
- University of Cologne, Faculty for Mathematics and Natural Sciences, Department of Chemistry, Institute for Inorganic Chemistry, Greinstrasse 6, D-50939 Köln, Germany.
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2
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Photophysics of α-azinyl-substituted 4,4-difluoro-8-(4-R-phenyl)-4-bora-3a,4a-diaza-s-indacenes. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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3
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Domcke W, Sobolewski AL. Water Oxidation and Hydrogen Evolution with Organic Photooxidants: A Theoretical Perspective. J Phys Chem B 2022; 126:2777-2788. [PMID: 35385277 DOI: 10.1021/acs.jpcb.2c00705] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this Perspective, we discuss a novel water-splitting scenario, namely the direct oxidation of water molecules by organic photooxidants in hydrogen-bonded chromophore-water complexes. In comparison with the established scenario of semiconductor-based water splitting, the distance of electron transfer processes is thereby reduced from mesoscopic scales to the Ångström scale, and the time scale is reduced from milliseconds to femtoseconds, which suppresses competing loss processes. The concept is illustrated by computational studies for the heptazine-H2O complex. The excited-state landscape of this complex has been characterized with ab initio electronic-structure methods and the proton-coupled electron-transfer dynamics has been explored with nonadiabatic dynamics simulations. A unique feature of the heptazine chromophore is the existence of a low-lying and exceptionally long-lived 1ππ* state in which a substantial part of the photon energy can be stored for hundreds of nanoseconds and is available for the oxidation of water molecules. The calculations reveal that the absorption spectra and the photochemical functionalities of heptazine chromophores can be systematically tailored by chemical substitution. The options of harvesting hydrogen and the problems posed by the high reactivity of OH radicals are discussed.
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Affiliation(s)
- Wolfgang Domcke
- Department of Chemistry, Technical University of Munich, D-85747 Garching, Germany
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4
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Morawski O, Gawryś P, Sadło J, Sobolewski AL. Photochemical Hydrogen Storage with Hexaazatrinaphthylene (HATN). Chemphyschem 2022; 23:e202200077. [PMID: 35377513 DOI: 10.1002/cphc.202200077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/14/2022] [Indexed: 11/10/2022]
Abstract
When irradiated with violet light, hexaazatrinaphthylene (HATN) extracts a hydrogen atom from an alcohol forming a long-living hydrogenated species. The kinetic isotope effect for fluorescence decay in deuterated methanol (1.56) indicates that the lowest singlet excited state of the molecule is a precursor for intermolecular hydrogen transfer. The photochemical hydrogenation occurs in several alcohols (methanol, ethanol, isopropanol) but not in water. Hydrogenated HATN can be detected optically by an absorption band at 1.78 eV as well as with EPR and NMR techniques. Mass spectroscopy of photoproducts reveal di-hydrogenated HATN structures along with methoxylated and methylated HATN molecules which are generated through the reaction with methoxy radicals (remnants from alcohol splitting). Experimental findings are consistent with the theoretical results which predicted that for the excited state of the HATN-solvent molecular complex, there exists a barrierless hydrogen transfer from methanol but a barrier for the similar oxidation of water.
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Affiliation(s)
- Olaf Morawski
- Institute of Physics Polish Academy of Sciences: Instytut Fizyki Polskiej Akademii Nauk, Radiation and Spectroscopy, Al. Lotnikow 32/46, 02-668, Warsaw, POLAND
| | - Paweł Gawryś
- Institute of Physics Polish Academy of Sciences: Instytut Fizyki Polskiej Akademii Nauk, Radiation and Spectroscopy, Al. Lotników 32/46, 02-668, Warszawa, POLAND
| | - Jarosław Sadło
- Institute of Nuclear Chemistry and Technology, Spectroscopy, ul. Dorodna 16, 03-195, Warsaw, POLAND
| | - Andrzej L Sobolewski
- Institute of Physics Polish Academy of Sciences: Instytut Fizyki Polskiej Akademii Nauk, Radiation and Spectroscopy, Al. Lotników 32/46, 02-668, Warsaw, POLAND
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5
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Hwang D, Schlenker CW. Photochemistry of carbon nitrides and heptazine derivatives. Chem Commun (Camb) 2021; 57:9330-9353. [PMID: 34528956 DOI: 10.1039/d1cc02745j] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We explore the photochemistry of polymeric carbon nitride (C3N4), an archetypal organic photocatalyst, and derivatives of its structural monomer unit, heptazine (Hz). Through spectroscopic studies and computational analysis, we have observed that Hz derivatives can engage in non-innocent hydrogen bonding interactions with hydroxylic species. The photochemistry of these complexes is influenced by intermolecular nπ*/ππ* mixing of non-bonding orbitals of each component and the relative energy of intermolecular charge-transfer (CT) states. Coupling of the former to the latter appears to facilitate proton-coupled electron transfer (PCET), resulting in biradical products. We have also observed that Hz derivatives exhibit an extremely rare inverted singlet/triplet energy splitting (ΔEST). In violation of Hund's multiplicity rules, the lowest energy singlet (S1) is stabilized relative to the lowest triplet (T1) electronic excited state. Exploiting this unique inverted ΔEST character has obvious implications for transformational discoveries in solid-state OLED lighting and photovoltaics. Harnessing this inverted ΔEST, paired with light-driven intermolecular PCET reactions, may enable molecular transformations relevant for applications ranging from solar energy storage to new classes of non-triplet photoredox catalysts for pharmaceutical development. To this end, we have explored the possibility of optically controlling the photochemistry of Hz derivatives using ultrafast pump-push-probe spectroscopy. In this case, the excited state branching ratios among locally excited states of the chromophore and the reactive intermolecular CT state can be manipulated with an appropriate secondary "push" excitation pulse. These results indicate that we can predictively redirect chemical reactivity with light in this system, which is an avidly sought achievement in the field of photochemistry. Looking forward, we anticipate future opportunities for controlling heptazine photochemistry, including manipulating PCET reactivity with a diverse array of substrates and optically delivering reducing equivalents with, for example, water as a partial source of electrons and protons. Furthermore, we wholly expect that, over the next decade, materials such as Hz derivatives, that exhibit inverted ΔEST character, will spawn a significant new research effort in the field of thin-film optoelectronics, where controlling recombination via triplet excitonic states can play a critical role in determining device performance.
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Affiliation(s)
- Doyk Hwang
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Cody W Schlenker
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA.,Molecular Engineering & Sciences Institute, University of Washington, Seattle, Washington 98195-1652, USA.,Clean Energy Institute, University of Washington, Seattle, Washington 98195-1653, USA.
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6
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Marsili E, Prlj A, Curchod BFE. Caveat when using ADC(2) for studying the photochemistry of carbonyl-containing molecules. Phys Chem Chem Phys 2021; 23:12945-12949. [PMID: 34085679 PMCID: PMC8207513 DOI: 10.1039/d1cp02185k] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 05/28/2021] [Indexed: 12/21/2022]
Abstract
Several electronic-structure methods are available to study the photochemistry and photophysics of organic molecules. Among them, ADC(2) stands as a sweet spot between computational efficiency and accuracy. As a result, ADC(2) has recently seen its number of applications booming, in particular to unravel the deactivation pathways and photodynamics of organic molecules. Despite this growing success, we demonstrate here that care has to be taken when studying the nonradiative pathways of carbonyl-containing molecules, as ADC(2) appears to suffer from a systematic flaw.
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Affiliation(s)
| | - Antonio Prlj
- Department of Chemistry, Durham University, Durham DH1 3LE, UK.
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7
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Jouvet C, Miyazaki M, Fujii M. Revealing the role of excited state proton transfer (ESPT) in excited state hydrogen transfer (ESHT): systematic study in phenol-(NH 3) n clusters. Chem Sci 2021; 12:3836-3856. [PMID: 34163653 PMCID: PMC8179502 DOI: 10.1039/d0sc06877b] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Excited State Hydrogen Transfer (ESHT), proposed at the end of the 20th century by the corresponding authors, has been observed in many neutral or protonated molecules and become a new paradigm to understand excited state dynamics/photochemistry of aromatic molecules. For example, a significant number of photoinduced proton-transfer reactions from X–H bonds have been re-defined as ESHT, including those of phenol, indole, tryptophan, aromatic amino acid cations and so on. Photo-protection mechanisms of biomolecules, such as isolated nucleic acids of DNA, are also discussed in terms of ESHT. Therefore, a systematic and up-to-date description of ESHT mechanism is important for researchers in chemistry, biology and related fields. In this review, we will present a general model of ESHT which unifies the excited state proton transfer (ESPT) and the ESHT mechanisms and reveals the hidden role of ESPT in controlling the reaction rate of ESHT. For this purpose, we give an overview of experimental and theoretical work on the excited state dynamics of phenol–(NH3)n clusters and related molecular systems. The dynamics has a significant dependence on the number of solvent molecules in the molecular cluster. Three-color picosecond time-resolved IR/near IR spectroscopy has revealed that ESHT becomes an electron transfer followed by a proton transfer in highly solvated clusters. The systematic change from ESHT to decoupled electron/proton transfer according to the number of solvent molecules is rationalized by a general model of ESHT including the role of ESPT. A general model of excited state hydrogen transfer (ESHT) which unifies ESHT and the excited state proton transfer (ESPT) is presented from experimental and theoretical works on phenol–(NH3)n. The hidden role of ESPT is revealed.![]()
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Affiliation(s)
- Christophe Jouvet
- CNRS, Aix Marseille Université, Physique des Interactions Ioniques et Moleculaires (PIIM), UMR 7345 13397 Marseille Cedex France .,World Research Hub Initiatives, Institute of Innovative Research, Tokyo Institute of Technology 4259-R1-15, Nagatsuta-cho, Midori-ku Yokohama 226-8503 Japan
| | - Mitsuhiko Miyazaki
- Natural Science Division, Faculty of Core Research, Ochanomizu University 2-1-1 Ohtsuka, Bunkyo-ku Tokyo 112-8610 Japan.,Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology 4259-R1-15, Nagatsuta-cho, Midori-ku Yokohama 226-8503 Japan
| | - Masaaki Fujii
- World Research Hub Initiatives, Institute of Innovative Research, Tokyo Institute of Technology 4259-R1-15, Nagatsuta-cho, Midori-ku Yokohama 226-8503 Japan.,Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology 4259-R1-15, Nagatsuta-cho, Midori-ku Yokohama 226-8503 Japan
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8
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Rabe EJ, Goldwyn HJ, Hwang D, Masiello DJ, Schlenker CW. Intermolecular Hydrogen Bonding Tunes Vibronic Coupling in Heptazine Complexes. J Phys Chem B 2020; 124:11680-11689. [PMID: 33315409 DOI: 10.1021/acs.jpcb.0c07719] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To better understand how hydrogen bonding influences the excited-state landscapes of aza-aromatic materials, we studied hydrogen-bonded complexes of 2,5,8-tris (4-methoxyphenyl)-1,3,4,6,7,9,9b-heptaazaphenalene (TAHz), a molecular photocatalyst related to graphitic carbon nitride, with a variety of phenol derivatives (R-PhOH). By varying the electron-withdrawing character of the para-substituent on the phenol, we can modulate the strength of the hydrogen bond. Using time-resolved photoluminescence, we extract a spectral component associated with the R-PhOH-TAHz hydrogen-bonded complex. Surprisingly, we noticed a striking change in the relative amplitude of vibronic peaks in the TAHz-centered emission as a function of R-group on phenol. To gain a physical understanding of these spectral changes, we employed a displaced-oscillator model of molecular emission to fit these spectra. This fit assumes that two vibrational modes are dominantly coupled to the emissive electronic transition and extracts their frequencies and relative nuclear displacements (related to the Huang-Rhys factor). With the aid of quantum chemical calculations, we found that heptazine ring-breathing and ring-puckering modes are likely responsible for the observed vibronic progression, and both modes indicate decreasing molecular distortion in the excited state with increasing hydrogen bond strength. This finding offers new insights into intermolecular excited-state hydrogen bonding, which is a crucial step toward controlling excited-state proton-coupled electron transfer and proton transfer reactions.
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Affiliation(s)
- Emily J Rabe
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Harrison J Goldwyn
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Doyk Hwang
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - David J Masiello
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Cody W Schlenker
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States.,Molecular Engineering and Sciences Institute, University of Washington, Seattle, Washington 98195-1652, United States.,Clean Energy Institute, University of Washington, Seattle, Washington 98195-1653, United States
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9
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Photobase effect for just-in-time delivery in photocatalytic hydrogen generation. Nat Commun 2020; 11:5179. [PMID: 33056986 PMCID: PMC7560858 DOI: 10.1038/s41467-020-18583-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 08/17/2020] [Indexed: 11/09/2022] Open
Abstract
Carbon dots (CDs) are a promising nanomaterial for photocatalytic applications. However, the mechanism of the photocatalytic processes remains the subject of a debate due to the complex internal structure of the CDs, comprising crystalline and molecular units embedded in an amorphous matrix, rendering the analysis of the charge and energy transfer pathways between the constituent parts very challenging. Here we propose that the photobasic effect, that is the abstraction of a proton from water upon excitation by light, facilitates the photoexcited electron transfer to the proton. We show that the controlled inclusion in CDs of a model photobase, acridine, resembling the molecular moieties found in photocatalytically active CDs, strongly increases hydrogen generation. Ultrafast spectroscopy measurements reveal proton transfer within 30 ps of the excitation. This way, we use a model system to show that the photobasic effect may be contributing to the photocatalytic H2 generation of carbon nanomaterials and suggest that it may be tuned to achieve further improvements. The study demonstrates the critical role of the understanding the dynamics of the CDs in the design of next generation photocatalysts.
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10
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Nguyen VT, Nguyen VD, Haug GC, Dang HT, Jin S, Li Z, Flores-Hansen C, Benavides BS, Arman HD, Larionov OV. Alkene Synthesis by Photocatalytic Chemoenzymatically Compatible Dehydrodecarboxylation of Carboxylic Acids and Biomass. ACS Catal 2019; 9:9485-9498. [PMID: 35223139 DOI: 10.1021/acscatal.9b02951] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Direct conversion of renewable biomass and bioderived chemicals to valuable synthetic intermediates for organic synthesis and materials science applications by means of mild and chemoselective catalytic methods has largely remained elusive. Development of artificial catalytic systems that are compatible with enzymatic reactions provides a synergistic solution to this enduring challenge by leveraging previously unachievable reactivity and selectivity modes. We report herein a dual catalytic dehydrodecarboxylation reaction that is enabled by a crossover of the photoinduced acridine-catalyzed O-H hydrogen atom transfer (HAT) and cobaloxime-catalyzed C-H-HAT processes. The reaction produces a variety of alkenes from readily available carboxylic acids. The reaction can be embedded in a scalable triple-catalytic cooperative chemoenzymatic lipase-acridine-cobaloxime process that allows for direct conversion of plant oils and biomass to long-chain terminal alkenes, precursors to bioderived polymers.
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Affiliation(s)
- Vu T. Nguyen
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Viet D. Nguyen
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Graham C. Haug
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Hang T. Dang
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Shengfei Jin
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Zhiliang Li
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Carsten Flores-Hansen
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Brenda S. Benavides
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Hadi D. Arman
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Oleg V. Larionov
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, Texas 78249, United States
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11
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Demianets I, Hunt JR, Dawlaty JM, Williams TJ. Optical pKa Control in a Bifunctional Iridium Complex. Organometallics 2019. [DOI: 10.1021/acs.organomet.8b00778] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ivan Demianets
- Donald P. and Katherine B. Loker Hydrocarbon Institute and Department of Chemistry, University of Southern California, Los Angeles, California 90089-1661, United States
| | - Jonathan R. Hunt
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Jahan M. Dawlaty
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Travis J. Williams
- Donald P. and Katherine B. Loker Hydrocarbon Institute and Department of Chemistry, University of Southern California, Los Angeles, California 90089-1661, United States
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12
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13
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Pang X, Ehrmaier J, Wu X, Jiang C, Xie W, Sobolewski AL, Domcke W. Photoinduced hydrogen-transfer reactions in pyridine-water clusters: Insights from excited-state electronic-structure calculations. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.09.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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14
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Janicki MJ, Szabla R, Šponer J, Góra RW. Solvation effects alter the photochemistry of 2-thiocytosine. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.06.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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15
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Rabe EJ, Corp KL, Sobolewski AL, Domcke W, Schlenker CW. Proton-Coupled Electron Transfer from Water to a Model Heptazine-Based Molecular Photocatalyst. J Phys Chem Lett 2018; 9:6257-6261. [PMID: 30265537 DOI: 10.1021/acs.jpclett.8b02519] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
To gain mechanistic understanding of heptazine-based photochemistry, we synthesized and studied 2,5,8-tris(4-methoxyphenyl)-1,3,4,6,7,9,9b-heptaazaphenalene (TAHz), a model molecular photocatalyst chemically related to carbon nitride. On the basis of time-resolved photoluminescence (TR-PL) spectroscopy, we kinetically reveal a new feature that emerges in aqueous dispersions of TAHz. Using global target analysis, we spectrally and kinetically resolve the new emission feature to be blue shifted from the steady-state luminescence, and observe a fast decay component exhibiting a kinetic isotope effect (KIE) of 2.9 in H2O versus D2O, not observed in the steady-state PL. From ab initio electronic-structure calculations, we attribute this new PL peak to the fluorescence of an upper excited state of mixed nπ*/ππ* character. In water, the KIE suggests the excited state is quenched by proton-coupled electron transfer, liberating hydroxyl radicals that we detect using terephthalic acid. Our findings are consistent with recent theoretical predictions that heptazine-based photocatalysts can participate in proton-coupled electron transfer with H2O.
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Affiliation(s)
- Emily J Rabe
- Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States
| | - Kathryn L Corp
- Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States
| | | | - Wolfgang Domcke
- Department of Chemistry , Technical University of Munich , D-85747 Garching , Germany
| | - Cody W Schlenker
- Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States
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16
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Esteves-López N, Coussan S, Dedonder-Lardeux C, Jouvet C. Photoinduced water splitting in pyridine water clusters. Phys Chem Chem Phys 2018; 18:25637-25644. [PMID: 27711521 DOI: 10.1039/c6cp04398d] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ab initio calculations predict that pyridine (Py) can act as a photo-catalyst to split water by the absorption of a UV photon following the reaction Py-H2O + hν → PyH˙ + OH˙. To test this prediction, we performed two types of experiments: in the first, we characterize the electronic spectroscopy of the PyH˙ radical in the gas phase. In the second, we evidence the reaction through the UV excitation of molecular Py-(H2O)n clusters obtained in a supersonic expansion and monitoring the PyH˙ reaction product. The results show unambiguously that PyH˙ is produced, and thus that water is split using pyridine as a photo-catalyst.
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Affiliation(s)
- Natalia Esteves-López
- CNRS, Aix-Marseille Université, Physique des Interactions Ioniques et Moléculaires (PIIM) UMR-7345, Marseille, France.
| | - Stephane Coussan
- CNRS, Aix-Marseille Université, Physique des Interactions Ioniques et Moléculaires (PIIM) UMR-7345, Marseille, France.
| | - Claude Dedonder-Lardeux
- CNRS, Aix-Marseille Université, Physique des Interactions Ioniques et Moléculaires (PIIM) UMR-7345, Marseille, France.
| | - Christophe Jouvet
- CNRS, Aix-Marseille Université, Physique des Interactions Ioniques et Moléculaires (PIIM) UMR-7345, Marseille, France.
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17
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Yamamoto K, Takatsuka K. On the photocatalytic cycle of water splitting with small manganese oxides and the roles of water clusters as direct sources of oxygen molecules. Phys Chem Chem Phys 2018; 20:6708-6725. [DOI: 10.1039/c7cp07171j] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A study on the photocatalytic cycle of water splitting and coupled proton electron-wavepacket transfer (CPEWT) as key processes of the mechanism.
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Affiliation(s)
- Kentaro Yamamoto
- Fukui Institute for Fundamental Chemistry
- Kyoto University
- Kyoto 606-8103
- Japan
| | - Kazuo Takatsuka
- Fukui Institute for Fundamental Chemistry
- Kyoto University
- Kyoto 606-8103
- Japan
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18
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Janicki MJ, Szabla R, Šponer J, Góra RW. Electron-driven proton transfer enables nonradiative photodeactivation in microhydrated 2-aminoimidazole. Faraday Discuss 2018; 212:345-358. [DOI: 10.1039/c8fd00086g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Prebiotically credible activator of non-enzymatic RNA template-copying, 2-aminoimidazole, is protected from destructive photochemistry by photoacidity.
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Affiliation(s)
- Mikołaj J. Janicki
- Department of Physical and Quantum Chemistry
- Faculty of Chemistry
- Wrocław University of Science and Technology
- 50-370 Wrocław
- Poland
| | - Rafał Szabla
- Institute of Physics
- Polish Academy of Sciences
- 02-668 Warsaw
- Poland
- Institute of Biophysics of the Czech Academy of Sciences
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences
- Brno
- Czech Republic
| | - Robert W. Góra
- Department of Physical and Quantum Chemistry
- Faculty of Chemistry
- Wrocław University of Science and Technology
- 50-370 Wrocław
- Poland
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19
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Ehrmaier J, Janicki MJ, Sobolewski AL, Domcke W. Mechanism of photocatalytic water splitting with triazine-based carbon nitrides: insights from ab initio calculations for the triazine–water complex. Phys Chem Chem Phys 2018; 20:14420-14430. [DOI: 10.1039/c8cp01998c] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Valuable theoretical insights into the mechanism of photocatalytic water-splitting using triazine as a model system for carbon-nitride materials.
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Affiliation(s)
- Johannes Ehrmaier
- Department of Chemistry
- Technical University of Munich
- D-85747 Garching
- Germany
| | - Mikołaj J. Janicki
- Department of Chemistry
- Technical University of Munich
- D-85747 Garching
- Germany
| | | | - Wolfgang Domcke
- Department of Chemistry
- Technical University of Munich
- D-85747 Garching
- Germany
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20
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Rodríguez-Prieto F, Corbelle CC, Fernández B, Pedro JA, Ríos Rodríguez MC, Mosquera M. Fluorescence quenching of the N-methylquinolinium cation by pairs of water or alcohol molecules. Phys Chem Chem Phys 2018; 20:307-316. [DOI: 10.1039/c7cp07057h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The proposed mechanism involves an electron transfer from H2O/ROH to the excited quinolinium, concerted with proton transfer to the second hydroxy molecule.
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Affiliation(s)
- Flor Rodríguez-Prieto
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS)
- Universidade de Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
- Departamento de Química Física
| | - Carlos Costa Corbelle
- Departamento de Química Física
- Facultade de Química
- Universidade de Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
| | - Berta Fernández
- Departamento de Química Física
- Facultade de Química
- Universidade de Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
| | - Jorge A. Pedro
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS)
- Universidade de Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
| | - M. Carmen Ríos Rodríguez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS)
- Universidade de Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
- Departamento de Química Física
| | - Manuel Mosquera
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS)
- Universidade de Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
- Departamento de Química Física
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21
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Takatsuka K. Theory of molecular nonadiabatic electron dynamics in condensed phases. J Chem Phys 2017; 147:174102. [DOI: 10.1063/1.4993240] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- Kazuo Takatsuka
- Fukui Institute for Fundamental Chemistry, Kyoto University, Sakyo-ku, Kyoto 606-8103, Japan
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22
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Yamazaki S, Diaz MA, Carlino TM, Gotluru C, Mazza MMA, Scott AM. Ultrafast Spectroscopic Dynamics of Quinacrine-Riboflavin Binding Protein Interactions. J Phys Chem B 2017; 121:8291-8299. [PMID: 28762739 DOI: 10.1021/acs.jpcb.7b05304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Redox active cofactors play a dynamic role inside protein binding active sites because the amino acids responsible for binding participate in electron transfer (ET) reactions. Here, we use femtosecond transient absorption (FsTA) spectroscopy to examine the ultrafast ET between quinacrine (Qc), an antimalarial drug with potential anticancer activity, and riboflavin binding protein (RfBP) with a known Kd = 264 nM. Steady-state absorption reveals a ∼ 10 nm red-shift in the ground state when QcH32+ is titrated with RfBP, and a Stern-Volmer analysis shows ∼84% quenching and a blue-shift of the QcH32+ photoluminescence to form a 1:1 binding ratio of the QcH32+-RfBP complex. Upon selective photoexcitation of QcH32+ in the QcH32+-RfBP complex, we observe charge separation in 7 ps to form 1[QcH3_red•+-RfBP•+], which persists for 138 ps. The FsTA spectra show the spectroscopic identification of QcH3_red•+, determined from spectroelectrochemical measurements in DMSO. We correlate our results to literature and report lifetimes that are 10-20× slower than the natural riboflavin, Rf-RfBP, complex and are oxygen independent. Driving force (ΔG) calculations, corrected for estimated dielectric constants for protein hydrophobic pockets, and Marcus theory depict a favorable one-electron ET process between QcH32+ and nearby redox active tyrosine (Tyr) or tryptophan (Trp) residues.
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Affiliation(s)
- Shiori Yamazaki
- University of Miami , Department of Chemistry, 1301 Memorial Drive, Coral Gables, Florida 33146, United States
| | - Matthew A Diaz
- University of Miami , Department of Chemistry, 1301 Memorial Drive, Coral Gables, Florida 33146, United States
| | - Thomas M Carlino
- University of Miami , Department of Chemistry, 1301 Memorial Drive, Coral Gables, Florida 33146, United States
| | - Chitra Gotluru
- University of Miami , Department of Chemistry, 1301 Memorial Drive, Coral Gables, Florida 33146, United States
| | - Mercedes M A Mazza
- University of Miami , Department of Chemistry, 1301 Memorial Drive, Coral Gables, Florida 33146, United States
| | - Amy M Scott
- University of Miami , Department of Chemistry, 1301 Memorial Drive, Coral Gables, Florida 33146, United States
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23
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Ehrmaier J, Karsili TNV, Sobolewski AL, Domcke W. Mechanism of Photocatalytic Water Splitting with Graphitic Carbon Nitride: Photochemistry of the Heptazine-Water Complex. J Phys Chem A 2017; 121:4754-4764. [PMID: 28592110 DOI: 10.1021/acs.jpca.7b04594] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Impressive progress has recently been achieved in photocatalytic hydrogen evolution with polymeric carbon nitride materials consisting of heptazine building blocks. However, the fundamental mechanistic principles of the catalytic cycle are as yet poorly understood. Here, we provide first-principles computational evidence that water splitting with heptazine-based materials can be understood as a molecular excited-state reaction taking place in hydrogen-bonded heptazine-water complexes. The oxidation of water occurs homolytically via an electron/proton transfer from water to heptazine, resulting in ground-state heptazinyl and OH radicals. It is shown that the excess hydrogen atom of the heptazinyl radical can be photodetached by a second photon, which regenerates the heptazine molecule. Alternatively to the photodetachment reaction, two heptazinyl radicals can recombine in a dark reaction to form H2, thereby regenerating two heptazine molecules. The proposed molecular photochemical reaction scheme within hydrogen-bonded chromophore-water complexes is complementary to the traditional paradigm of photocatalytic water splitting, which assumes the separation of electrons and holes over substantial time scales and distances.
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Affiliation(s)
- Johannes Ehrmaier
- Department of Chemistry, Technical University of Munich , Garching, Germany
| | - Tolga N V Karsili
- Department of Chemistry, Technical University of Munich , Garching, Germany.,Department of Chemistry, Temple University , Philadelphia, Pennsylvania 19122, United States
| | | | - Wolfgang Domcke
- Department of Chemistry, Technical University of Munich , Garching, Germany
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24
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Prlj A, Vannay L, Corminboeuf C. Fluorescence Quenching in BODIPY Dyes: The Role of Intramolecular Interactions and Charge Transfer. Helv Chim Acta 2017. [DOI: 10.1002/hlca.201700093] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Antonio Prlj
- Institut des Sciences et Ingénierie Chimiques; École polytechnique fédérale de Lausanne; CH-1015 Lausanne
| | - Laurent Vannay
- Institut des Sciences et Ingénierie Chimiques; École polytechnique fédérale de Lausanne; CH-1015 Lausanne
| | - Clemence Corminboeuf
- Institut des Sciences et Ingénierie Chimiques; École polytechnique fédérale de Lausanne; CH-1015 Lausanne
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25
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Malček M, Bučinský L, Barbieriková Z, Dorotíková S, Dvoranová D, Brezová V, Rapta P, Biskupič S. Protonation and electronic structure of 2,6-dichlorophenolindophenolate during reduction. A theoretical study including explicit solvent. J Mol Model 2016; 22:251. [PMID: 27686562 DOI: 10.1007/s00894-016-3109-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 09/01/2016] [Indexed: 10/20/2022]
Abstract
Protonation in the two-electron/two-proton reduction processes of 2,6-dichlorophenolindophenolate (DCIP) is investigated combining density functional theory (DFT) and molecular dynamics (MD) methods. DCIP (anion), DCIP•- (radical anion), and DCIP2- (dianion) are considered, including the electronic structure analysis from the prospective of quantum theory of atoms and molecules (QTAIM). It is shown that oxygen on the indophenolate moiety and nitrogen are the first and/or the second proton acceptor sites and their energetic order depends on the total charge of the system. MD simulations of differently charged species interacting with the solvent molecules have been performed for methanol, water, and oxonium cation (H3O+). Methanol and water molecules are found to form only hydrogen bonds with the solute irrespective of its charge. The calculated pKa values show that the imino group of DCIPH- is a weaker acid than water. While in the case of DCIP (and DCIP•-) plus oxonium cation, proton transfer from the solvent to the solute was evidenced for both aforementioned acceptor sites. In addition, MD simulations of bulks containing 15 and 43 molecules of water around the DCIP molecule have been performed, revealing the formation of 2-4 hydrogen bonds. Graphical Abstract 2,6-Dichlorophenolindophenolate interacts with solvent molecules (water, oxonium cation and methanol). Hydrogen transfer and electronic structure are studied by DFT and molecular dynamics methods.
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Affiliation(s)
- Michal Malček
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic. .,LAQV@REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre 687, 4169-007, Porto, Portugal.
| | - Lukáš Bučinský
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic
| | - Zuzana Barbieriková
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic
| | - Sandra Dorotíková
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic
| | - Dana Dvoranová
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic
| | - Vlasta Brezová
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic
| | - Peter Rapta
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic
| | - Stanislav Biskupič
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic
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26
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Yamamoto K, Takatsuka K. Dynamical mechanism of charge separation by photoexcited generation of proton–electron pairs in organic molecular systems. A nonadiabatic electron wavepacket dynamics study. Chem Phys 2016. [DOI: 10.1016/j.chemphys.2016.05.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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27
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Driscoll EW, Hunt JR, Dawlaty JM. Photobasicity in Quinolines: Origin and Tunability via the Substituents' Hammett Parameters. J Phys Chem Lett 2016; 7:2093-2099. [PMID: 27195691 DOI: 10.1021/acs.jpclett.6b00790] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
| | - Jonathan Ryan Hunt
- University of Southern California , Los Angeles, California 90089, United States
| | - Jahan M Dawlaty
- University of Southern California , Los Angeles, California 90089, United States
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28
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Wälz G, Usvyat D, Korona T, Schütz M. A hierarchy of local coupled cluster singles and doubles response methods for ionization potentials. J Chem Phys 2016; 144:084117. [DOI: 10.1063/1.4942234] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Gero Wälz
- Institute of Physical and Theoretical Chemistry, University of Regensburg, Regensburg D-93040, Germany
| | - Denis Usvyat
- Institute of Physical and Theoretical Chemistry, University of Regensburg, Regensburg D-93040, Germany
| | - Tatiana Korona
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Martin Schütz
- Institute of Physical and Theoretical Chemistry, University of Regensburg, Regensburg D-93040, Germany
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29
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Prlj A, Fabrizio A, Corminboeuf C. Rationalizing fluorescence quenching in meso-BODIPY dyes. Phys Chem Chem Phys 2016; 18:32668-32672. [DOI: 10.1039/c6cp06799a] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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30
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Liu X, Karsili TN, Sobolewski AL, Domcke W. Photocatalytic water splitting with acridine dyes: Guidelines from computational chemistry. Chem Phys 2016. [DOI: 10.1016/j.chemphys.2015.11.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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31
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Karsili TNV, Tuna D, Ehrmaier J, Domcke W. Photoinduced water splitting via benzoquinone and semiquinone sensitisation. Phys Chem Chem Phys 2015; 17:32183-93. [DOI: 10.1039/c5cp03831f] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The splitting of water into H˙ and OH˙ radicals by sensitisation of a redox-active chromophore with sunlight may eventually become a viable way of producing unlimited, clean and sustainable energy.
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Affiliation(s)
- Tolga N. V. Karsili
- Department of Chemistry
- Technische Universität München
- D-85747 Garching
- Germany
| | - Deniz Tuna
- Department of Chemistry
- Technische Universität München
- D-85747 Garching
- Germany
| | - Johannes Ehrmaier
- Department of Chemistry
- Technische Universität München
- D-85747 Garching
- Germany
| | - Wolfgang Domcke
- Department of Chemistry
- Technische Universität München
- D-85747 Garching
- Germany
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