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Shabashini A, Kumar Panja S, Biswas A, Bera S, Chandra Nandi G. ICT based photoacid probe for microsolvation and H-bonding assisted proton transfer process from solute to solvents. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Joung JF, Jeong M, Park S. Reliable experimental method for determination of photoacidity revealed by quantum chemical calculations. Phys Chem Chem Phys 2022; 24:21714-21721. [PMID: 36074805 DOI: 10.1039/d2cp03308a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photoacids are aromatic acids that exhibit significantly different acidities when they are electronically excited. Three experimental methods have been extensively used to determine the photoacidity, : fluorescence titration, the Förster cycle, and time-resolved experiments. However, the photoacidities determined by these experimental methods are not consistent. In this work, we used a theoretical method to evaluate the reliability of experimentally determined values. In particular, density functional theory (DFT) and time-dependent DFT calculations were used to obtain the changes in Gibbs free energy for acid dissociation reactions which are directly related to values. The Förster cycle, which is frequently used to experimentally determine the photoacidity due to its simplicity, yielded inconsistent results depending on how the transition energy was defined. We evaluated six empirical parameters extracted from the absorption and emission spectra of acidic and basic species of photoacids to adequately define the transition energy in the Förster cycle. And we found that the values obtained using the optical bandgap as the transition energy in the Förster cycle were in the best agreement with the results of quantum chemical calculations.
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Affiliation(s)
- Joonyoung F Joung
- Department of Chemistry and Research Institute for Natural Science, Korea University, Seoul, 02841, Korea.
| | - Minseok Jeong
- Department of Chemistry and Research Institute for Natural Science, Korea University, Seoul, 02841, Korea.
| | - Sungnam Park
- Department of Chemistry and Research Institute for Natural Science, Korea University, Seoul, 02841, Korea.
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Joung JF, Lee J, Hwang J, Choi K, Park S. A new visible light triggered Arrhenius photobase and its photo-induced reactions. NEW J CHEM 2020. [DOI: 10.1039/c9nj05404a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Visible light triggered Arrhenius photobases are of potential use for excited state hydroxide ion dissociation (ESHID), photo-induced pOH jump experiments, and base-catalyzed reactions.
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Affiliation(s)
- Joonyoung F. Joung
- Department of Chemistry and Research Institute for Natural Science
- Korea University
- Seoul
- Korea
| | - Jeeun Lee
- Department of Chemistry and Research Institute for Natural Science
- Korea University
- Seoul
- Korea
| | - Joungin Hwang
- Department of Chemistry and Research Institute for Natural Science
- Korea University
- Seoul
- Korea
| | - Kihang Choi
- Department of Chemistry and Research Institute for Natural Science
- Korea University
- Seoul
- Korea
| | - Sungnam Park
- Department of Chemistry and Research Institute for Natural Science
- Korea University
- Seoul
- Korea
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Joung JF, Kim S, Park S. Cationic Effect on the Equilibria and Kinetics of the Excited-State Proton Transfer Reaction of a Photoacid in Aqueous Solutions. J Phys Chem B 2018; 122:5087-5093. [DOI: 10.1021/acs.jpcb.8b00588] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
| | - Sangin Kim
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Sungnam Park
- Department of Chemistry, Korea University, Seoul 02841, Korea
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Burns DD, Teppang KL, Lee RW, Lokensgard ME, Purse BW. Fluorescence Turn-On Sensing of DNA Duplex Formation by a Tricyclic Cytidine Analogue. J Am Chem Soc 2017; 139:1372-1375. [PMID: 28080035 DOI: 10.1021/jacs.6b10410] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Most fluorescent nucleoside analogues are quenched when base stacked and some maintain their brightness, but there has been little progress toward developing nucleoside analogues that markedly increase their fluorescence upon duplex formation. Here, we report on the design and synthesis of a new tricyclic cytidine analogue, 8-diethylamino-tC (8-DEA-tC), that responds to DNA duplex formation with up to a 20-fold increase in fluorescent quantum yield as compared with the free nucleoside, depending on neighboring bases. This turn-on response to duplex formation is the greatest of any reported nucleoside analogue that can participate in Watson-Crick base pairing. Measurements of the quantum yield of 8-DEA-tC mispaired with adenosine and, separately, opposite an abasic site show that there is almost no fluorescence increase without the formation of correct Watson-Crick hydrogen bonds. Kinetic isotope effects from the use of deuterated buffer show that the duplex protects 8-DEA-tC against quenching by excited state proton transfer. These results, supported by DFT calculations, suggest a rationale for the observed photophysical properties that is dependent on duplex integrity and the electronic structure of the analogue.
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Affiliation(s)
- Dillon D Burns
- Department of Chemistry and Biochemistry, San Diego State University , San Diego, California 92182, United States
| | - Kristine L Teppang
- Department of Chemistry and Biochemistry, San Diego State University , San Diego, California 92182, United States
| | - Raymond W Lee
- Department of Chemistry and Biochemistry, San Diego State University , San Diego, California 92182, United States
| | - Melissa E Lokensgard
- Department of Chemistry and Biochemistry, San Diego State University , San Diego, California 92182, United States
| | - Byron W Purse
- Department of Chemistry and Biochemistry, San Diego State University , San Diego, California 92182, United States
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Joung JF, Kim S, Park S. Ionic effects on the proton transfer mechanism in aqueous solutions. Phys Chem Chem Phys 2017; 19:25509-25517. [DOI: 10.1039/c7cp04392a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Proton dissociation (PD) reactions of weak acids and proton transfer (PT) processes in aqueous solutions are strongly influenced by ions.
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Affiliation(s)
| | - Sangin Kim
- Department of Chemistry
- Korea University
- Seoul
- Korea
| | - Sungnam Park
- Department of Chemistry
- Korea University
- Seoul
- Korea
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Joung JF, Baek J, Kim Y, Lee S, Kim MH, Yoon J, Park S. Electronic relaxation dynamics of PCDA-PDA studied by transient absorption spectroscopy. Phys Chem Chem Phys 2016; 18:23096-104. [PMID: 27492212 DOI: 10.1039/c6cp03858a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Photo-curable polymers originating from 10,12-pentacosadiynoic acid (PCDA-PDA) are commonly used polydiacetylenes (PDAs). PCDA-PDA exhibits thermochromic properties undergoing a unique colorimetric transition from blue to red as the temperature is increased from low to high. In this work, we have carefully studied the temperature-dependent optical properties of PCDA-PDA by using UV-visible absorption, FTIR, Raman, and transient absorption (TA) spectroscopy in combination with quantum chemical calculations. Temperature-dependent UV-visible absorption spectra indicate that PCDA-PDA exhibits reversible thermochromic properties up to 60 °C and its thermochromic properties become irreversible above 60 °C. Such distinct thermochromic properties are also manifested in TA signals so that the electronically excited PCDA-PDA relaxes to the ground state via an intermediate state at 20 °C (blue form) but it relaxes directly back to the ground state at 80 °C (red form). The electronic relaxation dynamics of PCDA-PDA are comprehensively analyzed based on different kinetic models by using the global fitting analysis method. The intermediate state in the blue form of PCDA-PDA is clearly found to be responsible for fluorescence quenching. FTIR and Raman spectroscopy and quantum chemical calculations confirm that the H-bonds between the carboxylic acid groups in PCDA-PDA are broken at high temperatures leading to an irreversible structural change of PCDA-PDA.
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Affiliation(s)
| | - Junwoo Baek
- Department of Chemistry, Korea University, Seoul 136-701, Korea.
| | - Youngseo Kim
- Department of Chemistry, Korea University, Seoul 136-701, Korea.
| | - Songyi Lee
- Department of Chemistry and Nano Science, Global Top 5 Research Program, Ewha Womans University, Seoul, 120-750, Korea.
| | - Myung Hwa Kim
- Department of Chemistry and Nano Science, Global Top 5 Research Program, Ewha Womans University, Seoul, 120-750, Korea.
| | - Juyoung Yoon
- Department of Chemistry and Nano Science, Global Top 5 Research Program, Ewha Womans University, Seoul, 120-750, Korea.
| | - Sungnam Park
- Department of Chemistry, Korea University, Seoul 136-701, Korea.
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Gavish N, Promislow K. Dependence of the dielectric constant of electrolyte solutions on ionic concentration: A microfield approach. Phys Rev E 2016; 94:012611. [PMID: 27575183 DOI: 10.1103/physreve.94.012611] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Indexed: 06/06/2023]
Abstract
We present a microfield approach for studying the dependence of the orientational polarization of the water in aqueous electrolyte solutions upon the salt concentration and temperature. The model takes into account the orientation of the solvent dipoles due to the electric field created by ions, and the effect of thermal fluctuations. The model predicts a dielectric functional dependence of the form ɛ(c)=ɛ_{w}-βL(3αc/β),β=ɛ_{w}-ɛ_{ms}, where L is the Langevin function, c is the salt concentration, ɛ_{w} is the dielectric of pure water, ɛ_{ms} is the dielectric of the electrolyte solution at the molten salt limit, and α is the total excess polarization of the ions. The functional form gives a remarkably accurate description of the dielectric constant for a variety of salts and a wide range of concentrations.
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Affiliation(s)
- Nir Gavish
- Mathematics Department, Technion - Israel Institute of Technology, Haifa, 32000, Israel
| | - Keith Promislow
- Department of Mathematics, Michigan State University, East Lansing, Michigan 48864, USA
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