1
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Han GR, Lim E, Kang J, Hwang D, Heo J, Kim SK, Lee JW. Alcoholic Solvent-Mediated Excited-State Proton Transfer Dynamics of a Novel Dihydroxynaphthalene Dye. J Phys Chem A 2023; 127:7884-7891. [PMID: 37723599 DOI: 10.1021/acs.jpca.3c03170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
The excited-state proton transfer (ESPT) reaction is an important primary photochemical process because it is closely related to photophysical properties. Although ESPT research in aqueous solutions is predominant, alcoholic solvent-mediated ESPT studies are also significant in terms of photoacid-based reactions. Especially, the research for dihydroxynaphthalenes (DHNs) has been largely neglected due to the challenging data interpretation of two hydroxyl groups. A novel fluorescent dye, resveratrone, synthesized by light irradiation of resveratrol, which is famous for its antioxidant properties, can be regarded as a type of DHN, and it has distinctive optical properties, including high quantum yield, a large two-photon absorption coefficient, a large Stokes shift, and very high biocompatibility. In this study, we investigate the overall kinetics of the optical properties of resveratrone and find evidence for alcoholic solvent-mediated ESPT involvement in the radiative properties of resveratrone with a large Stokes shift. Our investigation provides an opportunity to revisit the overlooked photophysical properties of intriguing photoacid behavior and the large Stokes shift of the dihydroxynaphthalene dye.
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Affiliation(s)
- Gi Rim Han
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Eunhak Lim
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Jooyeon Kang
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Doyk Hwang
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Jiyoung Heo
- Department of Green Chemical Engineering, Sangmyung University, Chungnam 31066, Republic of Korea
| | - Seong Keun Kim
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Jong Woo Lee
- Department of Applied Chemistry, University of Seoul, 163 Seoulsiripdae-ro, Dongdaemun-gu, Seoul 02504, Republic of Korea
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2
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Knorr J, Sülzner N, Geissler B, Spies C, Grandjean A, Kutta RJ, Jung G, Nuernberger P. Ultrafast transient absorption and solvation of a super-photoacid in acetoneous environments. PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES : OFFICIAL JOURNAL OF THE EUROPEAN PHOTOCHEMISTRY ASSOCIATION AND THE EUROPEAN SOCIETY FOR PHOTOBIOLOGY 2022; 21:2179-2192. [PMID: 36178669 DOI: 10.1007/s43630-022-00287-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/08/2022] [Indexed: 12/13/2022]
Abstract
The phenomenon of photoacidity, i.e., an increase in acidity by several orders of magnitude upon electronic excitation, is frequently encountered in aromatic alcohols capable of transferring a proton to a suitable acceptor. A promising new class of neutral super-photoacids based on pyranine derivatives has been shown to exhibit pronounced solvatochromic effects. To disclose the underlying mechanisms contributing to excited-state proton transfer (ESPT) and the temporal characteristics of solvation and ESPT, we scrutinize the associated ultrafast dynamics of the strongest photoacid of this class, namely tris(1,1,1,3,3,3-hexafluoropropan-2-yl)8-hydroxypyrene-1,3,6-trisulfonate, in acetoneous environment, thereby finding experimental evidence for ESPT even under these adverse conditions for proton transfer. Juxtaposing results from time-correlated single-photon counting and femtosecond transient absorption measurements combined with a complete decomposition of all signal components, i.e., absorption of ground and excited states as well as stimulated emission, we disclose dynamics of solvation, rotational diffusion, and radiative relaxation processes in acetone and identify the relevant steps of ESPT along with the associated time scales.
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Affiliation(s)
- Johannes Knorr
- Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany.,Erlangen Graduate School in Advanced Optical Technologies (SAOT), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Paul-Gordan-Straße 6, 91052, Erlangen, Germany
| | - Niklas Sülzner
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780, Bochum, Germany.,Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Bastian Geissler
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstraße 31, 95053, Regensburg, Germany.,Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Christian Spies
- Biophysikalische Chemie, Universität des Saarlandes, 66123, Saarbrücken, Germany.,Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Alexander Grandjean
- Biophysikalische Chemie, Universität des Saarlandes, 66123, Saarbrücken, Germany
| | - Roger Jan Kutta
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstraße 31, 95053, Regensburg, Germany
| | - Gregor Jung
- Biophysikalische Chemie, Universität des Saarlandes, 66123, Saarbrücken, Germany
| | - Patrick Nuernberger
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstraße 31, 95053, Regensburg, Germany. .,Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany.
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3
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Nandi R, Amdursky N. The Dual Use of the Pyranine (HPTS) Fluorescent Probe: A Ground-State pH Indicator and an Excited-State Proton Transfer Probe. Acc Chem Res 2022; 55:2728-2739. [PMID: 36053265 PMCID: PMC9494743 DOI: 10.1021/acs.accounts.2c00458] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Indexed: 01/19/2023]
Abstract
Molecular fluorescent probes are an essential experimental tool in many fields, ranging from biology to chemistry and materials science, to study the localization and other environmental properties surrounding the fluorescent probe. Thousands of different molecular fluorescent probes can be grouped into different families according to their photophysical properties. This Account focuses on a unique class of fluorescent probes that distinguishes itself from all other probes. This class is termed photoacids, which are molecules exhibiting a change in their acid-base transition between the ground and excited states, resulting in a large change in their pKa values between these two states, which is thermodynamically described using the Förster cycle. While there are many different photoacids, we focus only on pyranine, which is the most used photoacid, with pKa values of ∼7.4 and ∼0.4 for its ground and excited states, respectively. Such a difference between the pKa values is the basis for the dual use of the pyranine fluorescent probe. Furthermore, the protonated and deprotonated states of pyranine absorb and emit at different wavelengths, making it easy to focus on a specific state. Pyranine has been used for decades as a fluorescent pH indicator for physiological pH values, which is based on its acid-base equilibrium in the ground state. While the unique excited-state proton transfer (ESPT) properties of photoacids have been explored for more than a half-century, it is only recently that photoacids and especially pyranine have been used as fluorescent probes for the local environment of the probe, especially the hydration layer surrounding it and related proton diffusion properties. Such use of photoacids is based on their capability for ESPT from the photoacid to a nearby proton acceptor, which is usually, but not necessarily, water. In this Account, we detail the photophysical properties of pyranine, distinguishing between the processes in the ground state and the ones in the excited state. We further review the different utilization of pyranine for probing different properties of the environment. Our main perspective is on the emerging use of the ESPT process for deciphering the hydration layer around the probe and other parameters related to proton diffusion taking place while the molecule is in the excited state, focusing primarily on bio-related materials. Special attention is given to how to perform the experiments and, most importantly, how to interpret their results. We also briefly discuss the breadth of possibilities in making pyranine derivatives and the use of pyranine for controlling dynamic reactions.
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Affiliation(s)
- Ramesh Nandi
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Haifa 3200003, Israel
| | - Nadav Amdursky
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Haifa 3200003, Israel
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4
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Sülzner N, Hättig C. Theoretical Study on the Photoacidity of Hydroxypyrene Derivatives in DMSO Using ADC(2) and CC2. J Phys Chem A 2022; 126:5911-5923. [PMID: 36037028 DOI: 10.1021/acs.jpca.2c04436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This work applies the thermodynamic Förster cycle to theoretically investigate the pKa*, i.e., excited-state pKa values of pyranine-derived superphotoacids developed by Jung and co-workers. The latter photoacids are strong enough to transfer a proton to the aprotic solvent dimethyl sulfoxide (DMSO). The Förster cycle provides access to pKa* via the ground-state pKa and the electronic excitation energies. We use the conductor-like screening model for real solvents (COSMO-RS) to compute the ground-state pKa and the correlated wavefunction-based methods ADC(2) and CC2 with the continuum solvation model COSMO to calculate the pKa change upon excitation. A comparison of the calculated UV/Vis absorption and fluorescence emission energies to the experimental results leads us to infer that this approach allows for a proper description of the electronic excitations. In particular, implicit solvation by means of the COSMO model appears to be sufficient for the treatment of these photoacids in DMSO. The calculations confirm the presumption that a charge redistribution from the hydroxy group to the aromatic ring and the electron-withdrawing substituents is the origin of photoacidity for these photoacids. Moreover, the calculations with the continuum solvation model predict that the pKa jump upon excitation decreases with increasing solvent polarity, as rationalized based on the Förster cycle.
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Affiliation(s)
- Niklas Sülzner
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Christof Hättig
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
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5
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Eckert S, Winghart MO, Kleine C, Banerjee A, Ekimova M, Ludwig J, Harich J, Fondell M, Mitzner R, Pines E, Huse N, Wernet P, Odelius M, Nibbering ETJ. Electronic Structure Changes of an Aromatic Amine Photoacid along the Förster Cycle. Angew Chem Int Ed Engl 2022; 61:e202200709. [PMID: 35325500 PMCID: PMC9322478 DOI: 10.1002/anie.202200709] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Indexed: 11/15/2022]
Abstract
Photoacids show a strong increase in acidity in the first electronic excited state, enabling real‐time studies of proton transfer in acid‐base reactions, proton transport in energy storage devices and biomolecular sensor protein systems. Several explanations have been proposed for what determines photoacidity, ranging from variations in solvation free energy to changes in electronic structure occurring along the four stages of the Förster cycle. Here we use picosecond nitrogen K‐edge spectroscopy to monitor the electronic structure changes of the proton donating group in a protonated aromatic amine photoacid in solution upon photoexcitation and subsequent proton transfer dynamics. Probing core‐to‐valence transitions locally at the amine functional group and with orbital specificity, we clearly reveal pronounced electronic structure, dipole moment and energetic changes on the conjugate photobase side. This result paves the way for a detailed electronic structural characterization of the photoacidity phenomenon.
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Affiliation(s)
- Sebastian Eckert
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, 12489, Berlin, Germany
| | - Marc-Oliver Winghart
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, 12489, Berlin, Germany
| | - Carlo Kleine
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, 12489, Berlin, Germany
| | - Ambar Banerjee
- Department of Physics, Stockholm University, AlbaNova University Center, 106 91, Stockholm, Sweden
| | - Maria Ekimova
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, 12489, Berlin, Germany
| | - Jan Ludwig
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, 12489, Berlin, Germany
| | - Jessica Harich
- Institute for Nanostructure and Solid State Physics, Center for Free-Electron Laser Science, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Mattis Fondell
- Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Strasse 15, 12489, Berlin, Germany
| | - Rolf Mitzner
- Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Strasse 15, 12489, Berlin, Germany
| | - Ehud Pines
- Department of Chemistry, Ben Gurion University of the Negev, P.O.B. 653, Beersheva, 84105, Israel
| | - Nils Huse
- Institute for Nanostructure and Solid State Physics, Center for Free-Electron Laser Science, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Philippe Wernet
- Department of Physics and Astronomy, Uppsala University, Box 516 Lägerhyddsvägen 1, 751 20, Uppsala, Sweden
| | - Michael Odelius
- Department of Physics, Stockholm University, AlbaNova University Center, 106 91, Stockholm, Sweden
| | - Erik T J Nibbering
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, 12489, Berlin, Germany
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6
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Sülzner N, Geissler B, Grandjean A, Jung G, Nuernberger P. Excited‐state Proton Transfer Dynamics of a Super‐Photoacid in Acetone‐Water Mixtures. CHEMPHOTOCHEM 2022. [DOI: 10.1002/cptc.202200041] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Niklas Sülzner
- Ruhr-Universitat Bochum Lehrstuhl für Theoretische Chemie GERMANY
| | - Bastian Geissler
- Universitat Regensburg Institut für Physikalische und Theoretische Chemie GERMANY
| | | | - Gregor Jung
- Universitat des Saarlandes Biophysikalische Chemie GERMANY
| | - Patrick Nuernberger
- Universitat Regensburg Institut für Physikalische und Theoretische Chemie Universitätsstraße 31 93053 Regensburg GERMANY
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7
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Eckert S, Winghart MO, Kleine C, Banerjee A, Ekimova M, Ludwig J, Harich J, Fondell M, Mitzner R, Pines E, Huse N, Wernet P, Odelius M, Nibbering ET. Electronic Structure Changes of an Aromatic Amine Photoacid along the Förster Cycle. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202200709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sebastian Eckert
- Max Born Institute for Non-Linear Optics and Short Pulse Spectroscopy: Max-Born-Institut fur Nichtlineare Optik und Kurzzeitspektroskopie C1 GERMANY
| | - Marc-Oliver Winghart
- Max Born Institute for Non-Linear Optics and Short Pulse Spectroscopy: Max-Born-Institut fur Nichtlineare Optik und Kurzzeitspektroskopie C1 GERMANY
| | - Carlo Kleine
- Max Born Institute for Non-Linear Optics and Short Pulse Spectroscopy: Max-Born-Institut fur Nichtlineare Optik und Kurzzeitspektroskopie C1 GERMANY
| | - Ambar Banerjee
- Stockholm University: Stockholms Universitet Chemistry SWEDEN
| | - Maria Ekimova
- Max Born Institute for Non-Linear Optics and Short Pulse Spectroscopy: Max-Born-Institut fur Nichtlineare Optik und Kurzzeitspektroskopie C1 GERMANY
| | - Jan Ludwig
- Max Born Institute for Non-Linear Optics and Short Pulse Spectroscopy: Max-Born-Institut fur Nichtlineare Optik und Kurzzeitspektroskopie C1 GERMANY
| | - Jessica Harich
- Center for Free Electron Laser Science Institute for Nanostructure and Solid State Physics GERMANY
| | - Mattis Fondell
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH: Helmholtz-Zentrum Berlin fur Materialien und Energie GmbH Institute for Methods and Instrumentation for Synchrotron Radiation Research GERMANY
| | - Rolf Mitzner
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH: Helmholtz-Zentrum Berlin fur Materialien und Energie GmbH Institute for Methods and Instrumentation for Synchrotron Radiation Research GERMANY
| | - Ehud Pines
- Ben-Gurion University of the Negev Chemistry ISRAEL
| | - Nils Huse
- Center for Free Electron Laser Science Institute for Nanostructure and Solid State Physics GERMANY
| | | | - Michael Odelius
- Stockholm University: Stockholms Universitet Chemistry SWEDEN
| | - Erik T.J. Nibbering
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie C1 Max Born Strasse 2A D-12489 Berlin GERMANY
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8
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Liu YH, Yu SB, Peng YJ, Wang CW, Zhu C, Lin SH. Excited-state intramolecular proton transfer with and without the assistance of vibronic-transition-induced skeletal deformation in phenol-quinoline. RSC Adv 2021; 11:37299-37306. [PMID: 35496430 PMCID: PMC9043822 DOI: 10.1039/d1ra07042h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/05/2021] [Indexed: 11/27/2022] Open
Abstract
The excited-state intramolecular proton transfer (ESIPT) reaction of two phenol–quinoline molecules (namely PQ-1 and PQ-2) were investigated using time-dependent density functional theory. The five-(six-) membered-ring carbocycle between the phenol and quinolone moieties in PQ-1 (PQ-2) actually causes a relatively loose (tight) hydrogen bond, which results in a small-barrier (barrier-less) on an excited-state potential energy surface with a slow (fast) ESIPT process with (without) involving the skeletal deformation motion up to the electronic excitation. The skeletal deformation motion that is induced from the largest vibronic excitation with low frequency can assist in decreasing the donor–acceptor distance and lowering the reaction barrier in the excited-state potential energy surface, and thus effectively enhance the ESIPT reaction for PQ-1. The Franck–Condon simulation indicated that the low-frequency mode with vibronic excitation 0 → 1′ is an original source of the skeletal deformation vibration. The present simulation presents physical insights for phenol–quinoline molecules in which relatively tight or loose hydrogen bonds can influence the ESIPT reaction process with and without the assistance of the skeletal deformation motion. Skeletal deformation motion is demonstrated from the specific vibronic excitation of phenol–quinoline molecules.![]()
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Affiliation(s)
- Yu-Hui Liu
- College of Physical Science and Technology, Bohai University Jinzhou 121013 China
| | - Shi-Bo Yu
- College of Physical Science and Technology, Bohai University Jinzhou 121013 China
| | - Ya-Jing Peng
- College of Physical Science and Technology, Bohai University Jinzhou 121013 China
| | - Chen-Wen Wang
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao-Tung University Hsinchu 30010 Taiwan
| | - Chaoyuan Zhu
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao-Tung University Hsinchu 30010 Taiwan .,Department of Applied Chemistry and Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan
| | - Sheng-Hsien Lin
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao-Tung University Hsinchu 30010 Taiwan
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9
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Grandjean A, Pérez Lustres JL, Jung G. Solvent‐Controlled Intermolecular Proton‐Transfer Follows an Irreversible Eigen‐Weller Model from fs to ns. CHEMPHOTOCHEM 2021. [DOI: 10.1002/cptc.202100177] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Alexander Grandjean
- Biophysikalische Chemie Universität des Saarlandes FR Chemie, Gebäude B2 2, Postfach 151150 D-66041 Saarbrücken Germany
| | - J. Luis Pérez Lustres
- Current Address: Fachbereich Physik Freie Universität Berlin Arnimallee 14 14195 Berlin Germany
- Experimental work conducted at former affiliation Physikalisch Chemisches Institut Universität Heidelberg Im Neuenheimer Feld 229 D-69120 Heidelberg Germany
| | - Gregor Jung
- Biophysikalische Chemie Universität des Saarlandes FR Chemie, Gebäude B2 2, Postfach 151150 D-66041 Saarbrücken Germany
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10
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Picconi D. Nonadiabatic quantum dynamics of the coherent excited state intramolecular proton transfer of 10-hydroxybenzo[h]quinoline. Photochem Photobiol Sci 2021; 20:1455-1473. [PMID: 34657277 DOI: 10.1007/s43630-021-00112-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 10/04/2021] [Indexed: 12/13/2022]
Abstract
The photoinduced nonadiabatic dynamics of the enol-keto isomerization of 10-hydroxybenzo[h]quinoline (HBQ) are studied computationally using high-dimensional quantum dynamics. The simulations are based on a diabatic vibronic coupling Hamiltonian, which includes the two lowest [Formula: see text] excited states and a [Formula: see text] state, which has high energy in the Franck-Condon zone, but significantly stabilizes upon excited state intramolecular proton transfer. A procedure, applicable to large classes of excited state proton transfer reactions, is presented to parametrize this model using potential energies, forces and force constants, which, in this case, are obtained by time-dependent density functional theory. The wave packet calculations predict a time scale of 10-15 fs for the photoreaction, and reproduce the time constants and the coherent oscillations observed in time-resolved spectroscopic studies performed on HBQ. In contrast to the interpretation given to the most recent experiments, it is found that the reaction initiated by [Formula: see text] photoexcitation proceeds essentially on a single potential energy surface, and the observed coherences bear signatures of Duschinsky mode-mixing along the reaction path. The dynamics after the [Formula: see text] excitation are instead nonadiabatic, and the [Formula: see text] state plays a major role in the relaxation process. The simulations suggest a mainly active role of the proton in the isomerization, rather than a passive migration assisted by the vibrations of the benzoquinoline backbone.
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Affiliation(s)
- David Picconi
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam-Golm, Germany.
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11
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Grandjean A, Pérez Lustres JL, Muth S, Maus D, Jung G. Steady-State Spectroscopy to Single Out the Contact Ion Pair in Excited-State Proton Transfer. J Phys Chem Lett 2021; 12:1683-1689. [PMID: 33560847 DOI: 10.1021/acs.jpclett.0c03593] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Despite the outstanding relevance of proton transfer reactions, investigations of the solvent dependence on the elementary step are scarce. We present here a probe system of a pyrene-based photoacid and a phosphine oxide, which forms stable hydrogen-bonded complexes in aprotic solvents of a broad polarity range. By using a photoacid, an excited-state proton transfer (ESPT) along the hydrogen bond can be triggered by a photon and observed via fluorescence spectroscopy. Two emission bands could be identified and assigned to the complexed photoacid (CPX) and the hydrogen-bonded ion pair (HBIP) by a solvatochromism analysis based on the Lippert-Mataga model. The latter indicates that the difference in the change of the permanent dipole moment of the two species upon excitation is ∼3 D. This implies a displacement of the acidic hydrogen by ∼65 pm, which is in quantitative agreement with a change of the hydrogen bond configuration from O-H···O to -O···H-O+.
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Affiliation(s)
- Alexander Grandjean
- Universität des Saarlandes, Biophysikalische Chemie, Campus, Geb. B2.2, D-66123 Saarbrücken, Germany
| | - J Luis Pérez Lustres
- Universität Heidelberg, Physikalisch Chemisches Institut, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
| | - Stephan Muth
- Universität des Saarlandes, Biophysikalische Chemie, Campus, Geb. B2.2, D-66123 Saarbrücken, Germany
| | - Daniel Maus
- Universität des Saarlandes, Biophysikalische Chemie, Campus, Geb. B2.2, D-66123 Saarbrücken, Germany
| | - Gregor Jung
- Universität des Saarlandes, Biophysikalische Chemie, Campus, Geb. B2.2, D-66123 Saarbrücken, Germany
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12
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Lee C, Chung S, Song H, Rhee YM, Lee E, Joo T. Excited State Proton Transfer of Quinone Cyanine 9: Implications on the Origin of Super‐Photoacidity. CHEMPHOTOCHEM 2020. [DOI: 10.1002/cptc.202000254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Changmin Lee
- Department of Chemistry Pohang University of Science and Technology (POSTECH) Pohang 37673 Republic of Korea
| | - Seyoung Chung
- Department of Chemistry Pohang University of Science and Technology (POSTECH) Pohang 37673 Republic of Korea
| | - Hayoung Song
- Department of Chemistry Pohang University of Science and Technology (POSTECH) Pohang 37673 Republic of Korea
| | - Young Min Rhee
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
| | - Eunsung Lee
- Department of Chemistry Pohang University of Science and Technology (POSTECH) Pohang 37673 Republic of Korea
| | - Taiha Joo
- Department of Chemistry Pohang University of Science and Technology (POSTECH) Pohang 37673 Republic of Korea
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13
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Verma P, Rosspeintner A, Dereka B, Vauthey E, Kumpulainen T. Broadband fluorescence reveals mechanistic differences in excited-state proton transfer to protic and aprotic solvents. Chem Sci 2020; 11:7963-7971. [PMID: 34094165 PMCID: PMC8163259 DOI: 10.1039/d0sc03316b] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Excited-state proton transfer (ESPT) to solvent is often explained according to the two-step Eigen-Weller model including a contact ion pair (CIP*) as an intermediate, but general applicability of the model has not been thoroughly examined. Furthermore, examples of the spectral identification of CIP* are scarce. Here, we report on a detailed investigation of ESPT to protic (H2O, D2O, MeOH and EtOH) and aprotic (DMSO) solvents utilizing a broadband fluorescence technique with sub-200 fs time resolution. The time-resolved spectra are decomposed into contributions from the protonated and deprotonated species and a clear signature of CIP* is identified in DMSO and MeOH. Interestingly, the CIP* intermediate is not observable in aqueous environment although the dynamics in all solvents are multi-exponential. Global analysis based on the Eigen-Weller model is satisfactory in all solvents, but the marked mechanistic differences between aqueous and organic solvents cast doubt on the physical validity of the rate constants obtained.
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Affiliation(s)
- Pragya Verma
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest Ansermet Geneva Switzerland +41 22 379 65 18 +41 22 379 36 58
| | - Arnulf Rosspeintner
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest Ansermet Geneva Switzerland +41 22 379 65 18 +41 22 379 36 58
| | - Bogdan Dereka
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest Ansermet Geneva Switzerland +41 22 379 65 18 +41 22 379 36 58
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest Ansermet Geneva Switzerland +41 22 379 65 18 +41 22 379 36 58
| | - Tatu Kumpulainen
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest Ansermet Geneva Switzerland +41 22 379 65 18 +41 22 379 36 58
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14
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Verma P, Rosspeintner A, Kumpulainen T. Propyl acetate/butyronitrile mixture is ideally suited for investigating the effect of dielectric stabilization on (photo)chemical reactions. RSC Adv 2020; 10:23682-23689. [PMID: 35517311 PMCID: PMC9054732 DOI: 10.1039/d0ra04525j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 06/12/2020] [Indexed: 11/21/2022] Open
Abstract
Characterization of propyl acetate/butyronitrile (PA/BuCN) mixtures by various spectroscopic techniques is described. The neat solvents have identical viscosities and refractive indices but their dielectric constants differ significantly. Detailed solvatochromic and titration data show that the mixtures do not exhibit specific solute-solvent interactions or significant dielectric enrichment effects. Therefore, the mixtures are ideally suited for investigating the effect of dielectric stabilization on (photo)chemical reactions. Dynamic Stokes shift experiments performed on two push-pull probes demonstrate that the solvation dynamics are significantly decelerated in the mixtures as compared to the neat solvents. Therefore, the mixtures allow for varying both the extent and time scale of the dielectric stabilization in a predictable manner.
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Affiliation(s)
- Pragya Verma
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest Ansermet Geneva Switzerland +41 22 379 6518 +41 22 379 6530
| | - Arnulf Rosspeintner
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest Ansermet Geneva Switzerland +41 22 379 6518 +41 22 379 6530
| | - Tatu Kumpulainen
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest Ansermet Geneva Switzerland +41 22 379 6518 +41 22 379 6530
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15
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Didier P, Kuchlyan J, Martinez-Fernandez L, Gosset P, Léonard J, Tor Y, Improta R, Mély Y. Deciphering the pH-dependence of ground- and excited-state equilibria of thienoguanine. Phys Chem Chem Phys 2020; 22:7381-7391. [PMID: 32211689 DOI: 10.1039/c9cp06931c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The thienoguanine nucleobase (thGb) is an isomorphic fluorescent analogue of guanine. In aqueous buffer at neutral pH, thGb exists as a mixture of two ground-state H1 and H3 keto-amino tautomers with distinct absorption and emission spectra and high quantum yield. In this work, we performed the first systematic photophysical characterization of thGb as a function of pH (2 to 12). Steady-state and time-resolved fluorescence spectroscopies, supplemented with theoretical calculations, enabled us to identify three additional thGb forms, resulting from pH-dependent ground-state and excited-state reactions. Moreover, a thorough analysis allowed us to retrieve their individual absorption and emission spectra as well as the equilibrium constants which govern their interconversion. From these data, the complete photoluminescence pathway of thGb in aqueous solution and its dependence as a function of pH was deduced. As the identified forms differ by their spectra and fluorescence lifetime, thGb could be used as a probe for sensing local pH changes under acidic conditions.
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Affiliation(s)
- Pascal Didier
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS Université de Strasbourg, Faculté de Pharmacie, 74 route du Rhin, 67401 Illkirch, France.
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16
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Kumpulainen T, Panman MR, Bakker BH, Hilbers M, Woutersen S, Brouwer AM. Accelerating the Shuttling in Hydrogen-Bonded Rotaxanes: Active Role of the Axle and the End Station. J Am Chem Soc 2019; 141:19118-19129. [PMID: 31697078 PMCID: PMC6923795 DOI: 10.1021/jacs.9b10005] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
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The relation between the chemical structure and the mechanical
behavior of molecular machines is of paramount importance for a rational
design of superior nanomachines. Here, we report on a mechanistic
study of a nanometer scale translational movement in two bistable
rotaxanes. Both rotaxanes consist of a tetra-amide macrocycle interlocked
onto a polyether axle. The macrocycle can shuttle between an initial
succinamide station and a 3,6-dihydroxy- or 3,6-di-tert-butyl-1,8-naphthalimide end stations. Translocation of the macrocycle
is controlled by a hydrogen-bonding equilibrium between the stations.
The equilibrium can be perturbed photochemically by either intermolecular
proton or electron transfer depending on the system. To the best of
our knowledge, utilization of proton transfer from a conventional
photoacid for the operation of a molecular machine is demonstrated
for the first time. The shuttling dynamics are monitored by means
of UV–vis and IR transient absorption spectroscopies. The polyether
axle accelerates the shuttling by ∼70% compared to a structurally
similar rotaxane with an all-alkane thread of the same length. The
acceleration is attributed to a decrease in activation energy due
to an early transition state where the macrocycle partially hydrogen
bonds to the ether group of the axle. The dihydroxyrotaxane exhibits
the fastest shuttling speed over a nanometer distance (τshuttling ≈ 30 ns) reported to date. The shuttling in
this case is proposed to take place via a so-called harpooning mechanism
where the transition state involves a folded conformation due to the
hydrogen-bonding interactions with the hydroxyl groups of the end
station.
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Affiliation(s)
- Tatu Kumpulainen
- Van't Hoff Institute for Molecular Sciences, Faculty of Science , University of Amsterdam , P.O. Box 94157, 1090 GD Amsterdam , The Netherlands
| | - Matthijs R Panman
- Van't Hoff Institute for Molecular Sciences, Faculty of Science , University of Amsterdam , P.O. Box 94157, 1090 GD Amsterdam , The Netherlands
| | - Bert H Bakker
- Van't Hoff Institute for Molecular Sciences, Faculty of Science , University of Amsterdam , P.O. Box 94157, 1090 GD Amsterdam , The Netherlands
| | - Michiel Hilbers
- Van't Hoff Institute for Molecular Sciences, Faculty of Science , University of Amsterdam , P.O. Box 94157, 1090 GD Amsterdam , The Netherlands
| | - Sander Woutersen
- Van't Hoff Institute for Molecular Sciences, Faculty of Science , University of Amsterdam , P.O. Box 94157, 1090 GD Amsterdam , The Netherlands
| | - Albert M Brouwer
- Van't Hoff Institute for Molecular Sciences, Faculty of Science , University of Amsterdam , P.O. Box 94157, 1090 GD Amsterdam , The Netherlands
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17
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Jen M, Jeon K, Lee S, Hwang S, Chung WJ, Pang Y. Ultrafast intramolecular proton transfer reactions and solvation dynamics of DMSO. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2019; 6:064901. [PMID: 31867409 PMCID: PMC6920016 DOI: 10.1063/1.5129446] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 11/21/2019] [Indexed: 05/27/2023]
Abstract
Ultrafast intramolecular proton transfers of 1,2-dihydroxyanthraquinone (alizarin-h2) and its deuterated product (alizarin-d2) in dimethyl sulfoxide (DMSO) have been investigated by femtosecond stimulated Raman spectroscopy. The population dynamics in the solute vibrational mode of νC=O and the coherent oscillations observed in all of the skeletal vibrational modes νC=O and νC=C clearly showed the ultrafast excited-state intramolecular proton transfer dynamics of 110 and 170 fs for alizarin-h2 and alizarin-d2, respectively. Interestingly, we have observed that the solvent vibrational modes νS=O and νCSC may also represent ultrafast structural dynamics at the frequencies for its "free" or "aggregated" species. From the kinetic analysis of the νS=O and νCSC modes of DMSO, the ultrafast changes in the solvation or intermolecular interactions between DMSO molecules initiated by the structural changes of solute molecules have been thoroughly investigated. We propose that the solvent vibrational modes νS=O and νCSC of DMSO can be used as a "sensor" for ultrafast chemical reactions accompanying the structural changes and subsequent solute-solvent interactions.
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Affiliation(s)
| | | | - Sebok Lee
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, South Korea
| | - Sunjoo Hwang
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, South Korea
| | - Won-jin Chung
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, South Korea
| | - Yoonsoo Pang
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, South Korea
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18
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Norell J, Ljungdahl A, Odelius M. Interdependent Electronic Structure, Protonation, and Solvatization of Aqueous 2-Thiopyridone. J Phys Chem B 2019; 123:5555-5567. [PMID: 31244103 DOI: 10.1021/acs.jpcb.9b03084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
2-Thiopyridone (2-TP), a common model system for excited-state proton transfer, has been simulated in aqueous solution with ab initio molecular dynamics. The interplay of electronic structure, protonation, and solvatization is investigated by comparison of three differently protonated molecular forms and between the lowest singlet and triplet electronic states. An interdependence clearly manifests in the mixed-character T1 state for the 2-TP form, systematic structural distortions of the 2-mercaptopyridine (2-MP) form, and photobase protolysis of the 2-TP- form, in the aqueous phase. In comparison, simplified continuum models for the solvatization are found to be significantly inaccurate for several of the species. To facilitate future computational studies, we therefore present a minimal representative solvatization complex for each stable form and electronic state. Our findings demonstrate the importance of explicit solvatization of the compound and sets the stage for including it also in future studies.
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Affiliation(s)
- Jesper Norell
- Department of Physics, AlbaNova University Center , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Anton Ljungdahl
- Department of Physics, AlbaNova University Center , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Michael Odelius
- Department of Physics, AlbaNova University Center , Stockholm University , SE-106 91 Stockholm , Sweden
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19
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Cao Y, Eng J, Penfold TJ. Excited State Intramolecular Proton Transfer Dynamics for Triplet Harvesting in Organic Molecules. J Phys Chem A 2019; 123:2640-2649. [DOI: 10.1021/acs.jpca.9b00813] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Y. Cao
- Chemistry- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - J. Eng
- Chemistry- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - T. J. Penfold
- Chemistry- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
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