1
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Du W, Gao Y, Stankus B, Xu X, Yong H, Weber PM. Ultrafast conformational dynamics of Rydberg-excited N-methyl piperidine. Phys Chem Chem Phys 2021; 23:27417-27427. [PMID: 34860225 DOI: 10.1039/d1cp04236j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have observed the ultrafast conformational dynamics of electronically excited N-methyl piperidine (NMP) using time-resolved Rydberg fingerprint spectroscopy. Optical excitation at various wavelengths ranging from 212 nm to 229 nm leads to the 3s or 3p Rydberg states and induces coherent oscillatory motions with periods of about 700 fs. These coherent motions survive the internal conversion from 3p to 3s but then dephase on a time scale of a few oscillations. Intramolecular vibrational energy redistribution on a picosecond time scale leads to an equilibrium between two conformeric structures that are separated in binding energy by 0.09 eV. Model calculations using the DFT-SIC method are in excellent agreement with the experiments and identify the conformers as the chair and twist structures of NMP. The analysis of the equilibrium parameters at long time delays as a function of excitation wavelength allows for the extraction of thermodynamic parameters for the conformeric transformation. We derive an enthalpy of the chair to twist reaction in the 3s excited state of 62 meV with an entropy of 19.70 J mol-1 K-1. An activation energy of 276 meV is also obtained with a kinetic model.
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Affiliation(s)
- Wenpeng Du
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
| | - Yan Gao
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
| | - Brian Stankus
- Department of Chemistry and Biochemistry, Western Connecticut State University, Danbury, Connecticut 06810, USA
| | - Xuan Xu
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
| | - Haiwang Yong
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
| | - Peter M Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
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2
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Marlton SJP, McKinnon BI, Greißel P, Shiels OJ, Ucur B, Trevitt AJ. Picosecond excited-state lifetimes of protonated indazole and benzimidazole: The role of the N-N bond. J Chem Phys 2021; 155:184302. [PMID: 34773941 DOI: 10.1063/5.0071847] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Certain chemical groups give rise to characteristic excited-state deactivation mechanisms. Here, we target the role of a protonated N-N chemical group in the excited-state deactivation of protonated indazole by comparison to its isomer that lacks this group, protonated benzimidazole. Gas-phase protonated indazole and protonated benzimidazole ions are investigated at room temperature using picosecond laser pump-probe photodissociation experiments in a linear ion-trap. Excited state lifetimes are measured across a range of pump energies (4.0-5.4 eV). The 1ππ* lifetimes of protonated indazole range from 390 ± 70 ps using 4.0 eV pump energy to ≤18 ps using 4.6 eV pump energy. The 1ππ* lifetimes of protonated benzimidazole are systematically longer, ranging from 3700 ± 1100 ps at 4.6 eV pump energy to 400 ± 200 ps at 5.4 eV. Based on these experimental results and accompanying quantum chemical calculations and potential energy surfaces, the shorter lifetimes of protonated indazole are attributed to πσ* state mediated elongation of the protonated N-N bond.
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Affiliation(s)
- Samuel J P Marlton
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Benjamin I McKinnon
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Phillip Greißel
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Oisin J Shiels
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Boris Ucur
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Adam J Trevitt
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
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3
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Loftus LM, Olson EC, Stewart DJ, Phillips AT, Arumugam K, Cooper TM, Haley JE, Grusenmeyer TA. Zn Coordination and the Identity of the Halide Ancillary Ligand Dramatically Influence the Excited-State Dynamics and Bimolecular Reactions of 2,3-Di(pyridin-2-yl)benzo[ g]quinoxaline. Inorg Chem 2021; 60:16570-16583. [PMID: 34662517 DOI: 10.1021/acs.inorgchem.1c02484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The optical properties of coordination complexes with ligands containing nitrogen heterocycles have been extensively studied for decades. One subclass of these materials, metal complexes utilizing substituted pyrazines and quinoxalines as ligands, has been employed in a variety of photochemical applications ranging from photodynamic therapy to organic light-emitting diodes. A vast majority of this work focuses on characterization of the metal-to-ligand charge-transfer states in these metal complexes; however, literature reports rarely investigate the photophysics of the parent pyrazine or quinoxaline ligand or perform control experiments utilizing metal complexes that lack low-lying charge-transfer (CT) states in order to determine how metal-atom coordination influences the photophysical properties of the ligand. With this in mind, we examined the steady-state and time-resolved photophysics of 2,3-di(pyridin-2-yl)benzo[g]quinoxaline (dpb) and explored how the coordination of ZnX2 (X = Cl-, Br-, I-) affects the photophysical properties of dpb. In dpb, we find that the dominant mode of deactivation from the singlet excited state is intersystem crossing (ISC). Coordination of ZnX2 perturbs the relative energies of the ππ* and nπ* excited states of dpb, leading to drastically different rates of ISC as well as radiative and nonradiative decay in the [Zn(dpb)X2] complexes compared to dpb. These differences in the rates change the dominant singlet-excited-state decay pathway from ISC in dpb to a mixture of ISC and fluorescence in [Zn(dpb)Cl2] and [Zn(dpb)Br2] and to nonradiative decay in [Zn(dpb)I2]. Coordination of ZnX2 and the choice of the halide ligand also have profound effects on the rate constants for excited-state bimolecular reactions, including triplet-triplet annihilation and oxygen quenching. These results demonstrate that metal coordination, even in complexes lacking low-lying CT states, and the choice of the ancillary ligand can dramatically alter the photophysical properties of chromophores containing nitrogen heterocycles.
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Affiliation(s)
- Lauren M Loftus
- Materials and Manufacturing Directorate, Functional Materials Division, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433-7750, United States.,General Dynamics Information Technology, 5100 Springfield Pike, Dayton, Ohio 45431, United States
| | - Emma C Olson
- Materials and Manufacturing Directorate, Functional Materials Division, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433-7750, United States.,Southwestern Ohio Council for Higher Education, Dayton, Ohio 45420, United States
| | - David J Stewart
- Materials and Manufacturing Directorate, Functional Materials Division, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433-7750, United States
| | - Alexis T Phillips
- Materials and Manufacturing Directorate, Functional Materials Division, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433-7750, United States.,Southwestern Ohio Council for Higher Education, Dayton, Ohio 45420, United States
| | - Kuppuswamy Arumugam
- Wright State University, Department of Chemistry, 3640 Colonel Glenn Highway, Dayton, Ohio 45435, United States
| | - Thomas M Cooper
- Materials and Manufacturing Directorate, Functional Materials Division, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433-7750, United States
| | - Joy E Haley
- Materials and Manufacturing Directorate, Functional Materials Division, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433-7750, United States
| | - Tod A Grusenmeyer
- Materials and Manufacturing Directorate, Functional Materials Division, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433-7750, United States
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4
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Robertson PA, Villani L, Robertson EG. Conformer Specific Ultraviolet and Infrared Detection of Nicotine in the Vapor Phase. J Phys Chem A 2019; 123:10152-10157. [PMID: 31644291 DOI: 10.1021/acs.jpca.9b09113] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A gas-phase electronic spectrum of nicotine in a supersonic expansion has been recorded using two-color resonant two-photon ionization spectroscopy. Efficient photoionization was achievable only via the pyridine chromophore owing to poor Franck-Condon overlap in the N-methylpyrrolidine moiety. Two conformers of nicotine have been characterized and assigned by infrared-ultraviolet (IR-UV) ion depletion and IR-UV hole-burning spectroscopy, in combination with quantum chemical techniques. Trans-A with nitrogen atoms further apart is more stable by 2 kJ mol-1 and the most populated conformer in the supersonic jet, owing this stability to a stronger inter-ring CH···N hydrogen bond than the trans-B counterpart.
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Affiliation(s)
- Patrick A Robertson
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science , La Trobe University , Melbourne , Victoria 3086 , Australia.,School of Chemistry , University of Bristol , Cantock's Close , Bristol BS8 1TS , United Kingdom
| | - Luigi Villani
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science , La Trobe University , Melbourne , Victoria 3086 , Australia
| | - Evan G Robertson
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science , La Trobe University , Melbourne , Victoria 3086 , Australia
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5
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Ben Nasr F, Alata I, Scuderi D, Lepère V, Brenner V, Jaïdane NE, Zehnacker A. Effects of complexation with sulfuric acid on the photodissociation of protonated Cinchona alkaloids in the gas phase. Phys Chem Chem Phys 2019; 21:15439-15451. [PMID: 31257399 DOI: 10.1039/c9cp01518c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effect of complexation with sulfuric acid on the photo-dissociation of protonated Cinchona alkaloids, namely cinchonidine (Cd), quinine (Qn) and quinidine (Qd), is studied by combining laser spectroscopy with quantum chemical calculations. The protonated complexes are structurally characterized in a room-temperature ion trap by means of infra-red multiple photon dissociation (IRMPD) spectroscopy in the fingerprint and the ν(XH) (X = C, N, O) stretch regions. Comparison with density functional theory calculations including dispersion (DFT-D) unambiguously shows that the complex consists of a doubly protonated Cinchona alkaloid strongly bound to a bisulfate HSO4- anion, which bridges the two protonated sites of the Cinchona alkaloid. UV excitation of the complex does not induce loss of specific photo fragments, in contrast to the protonated monomer or dimer, for which photo-specific fragments were observed. Indeed the UV-induced fragmentation pattern is identical to that observed in collision-induced dissociation experiments. Analysis of the nature of the first electronic transitions at the second order approximate coupled-cluster level (CC2) explains the difference in the behavior of the complex relative to the monomer or dimer towards UV excitation.
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Affiliation(s)
- Feriel Ben Nasr
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France. and Laboratoire de Spectroscopie Atomique, Moléculaire et Applications (LSAMA) Université de Tunis El Manar, LSAMA, Tunis 1060, Tunisia
| | - Ivan Alata
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France.
| | - Debora Scuderi
- Univ. Paris-Sud, Laboratoire de Chimie Physique, UMR 8000, and CNRS, Orsay, F-91405, France
| | - Valeria Lepère
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France.
| | | | - Nejm-Eddine Jaïdane
- Laboratoire de Spectroscopie Atomique, Moléculaire et Applications (LSAMA) Université de Tunis El Manar, LSAMA, Tunis 1060, Tunisia
| | - Anne Zehnacker
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France.
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6
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Marlton SJP, McKinnon BI, Ucur B, Maccarone AT, Donald WA, Blanksby SJ, Trevitt AJ. Selecting and identifying gas-phase protonation isomers of nicotineH+ using combined laser, ion mobility and mass spectrometry techniques. Faraday Discuss 2019; 217:453-475. [DOI: 10.1039/c8fd00212f] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protonation isomers of gas-phase nicotineH+ are separated and assigned using a combination of FAIMS and UV photodissociation action spectroscopy.
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Affiliation(s)
| | | | - Boris Ucur
- School of Chemistry
- University of Wollongong
- Wollongong
- Australia
| | | | | | - Stephen J. Blanksby
- Central Analytical Research Facility
- Institute for Future Environments
- Queensland University of Technology
- Brisbane
- Australia
| | - Adam J. Trevitt
- School of Chemistry
- University of Wollongong
- Wollongong
- Australia
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7
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Varras PC, Gritzapis PS, Fylaktakidou KC. An explanation of the very low fluorescence and phosphorescence in pyridine: a CASSCF/CASMP2 study. Mol Phys 2017. [DOI: 10.1080/00268976.2017.1371800] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Panayiotis C. Varras
- Molecular Biology and Genetics Department, Democritus University of Thrace, Alexandroupolis, Greece
| | - Panagiotis S. Gritzapis
- Molecular Biology and Genetics Department, Democritus University of Thrace, Alexandroupolis, Greece
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8
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Sah C, Jacob L, Saraswat M, Venkataramani S. Does a Nitrogen Lone Pair Lead to Two Centered-Three Electron (2c-3e) Interactions in Pyridyl Radical Isomers? J Phys Chem A 2017; 121:3781-3791. [PMID: 28423280 DOI: 10.1021/acs.jpca.7b01501] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Each of the three isomeric pyridyl radicals (2-, 3-, and 4-dehydropyridines) contains a lone pair and an unpaired electron. As a result, a potential two centered-three electron interaction between the radical electron and the lone pair through-space (TS) and/or through-bond (TB) can exist that may influence the stability of the radicals. Due to the change in geometrical positions relative to each other, the strength of interaction can be varied. In this study, we investigated the structural and stability aspects of pyridyl radical isomers with a major emphasis on the interaction of a nitrogen lone pair with the radical center. In order to obtain evidence for such interactions, protonated and N-oxide analogues of the corresponding isomeric pyridyl radicals have been considered in such a way to understand the consequences due to unavailability of the lone pair. Similarly, electron attachment and detachment energies at the radical center (vertical detachment energy, VDE, of corresponding anions and vertical ionization energy, VIE, of radical isomers) have been calculated to find out the interaction trend upon modification at the radical center. Different levels of theory including (U)B3LYP/cc-pVTZ, (U)M06/cc-pVTZ, CBS-QB3, single-point energy calculations at (U)CCSD(T)/cc-pVTZ, and multireference CASSCF/cc-pVTZ methods have been employed in this regard. A closer inspection of geometries, relative stability order, spin density, electrostatic potential, molecular orbitals, NBO analysis, and vibrational analysis have showed a strong and stabilizing TS interaction between the radical center and the lone pair in the case of the 2-pyridyl radical. On the other hand, the 4-pyridyl radical showed stabilizing interactions only via TB coupling, whereas the TS interaction is nonexistent. Despite the presence of both interactions in the case of the 3-pyridyl radical, their overall influence is less effective toward stability.
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Affiliation(s)
- Chitranjan Sah
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali , Sector 81, SAS Nagar, Knowledge City, Mohali, Punjab 140306, India
| | - Lilit Jacob
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali , Sector 81, SAS Nagar, Knowledge City, Mohali, Punjab 140306, India
| | - Mayank Saraswat
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali , Sector 81, SAS Nagar, Knowledge City, Mohali, Punjab 140306, India
| | - Sugumar Venkataramani
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali , Sector 81, SAS Nagar, Knowledge City, Mohali, Punjab 140306, India
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9
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Noble JA, Dedonder-Lardeux C, Mascetti J, Jouvet C. Electronic Spectroscopy of Protonated 1-Aminopyrene in a Cold Ion Trap. Chem Asian J 2017; 12:1523-1531. [DOI: 10.1002/asia.201700327] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 03/31/2017] [Indexed: 12/28/2022]
Affiliation(s)
- Jennifer Anna Noble
- Institut des Sciences Moléculaires (ISM, UMR 5255); Université de Bordeaux and CNRS; 351 Cours de la Libération F-33405 Talence France
| | - Claude Dedonder-Lardeux
- CNRS, Aix-Marseille Université, PIIM UMR 7345; Avenue Escadrille Normandie-Niémen 13397 Marseille Cedex 20 France
| | - Joëlle Mascetti
- Institut des Sciences Moléculaires (ISM, UMR 5255); Université de Bordeaux and CNRS; 351 Cours de la Libération F-33405 Talence France
| | - Christophe Jouvet
- CNRS, Aix-Marseille Université, PIIM UMR 7345; Avenue Escadrille Normandie-Niémen 13397 Marseille Cedex 20 France
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10
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O'Connor GD, Chan B, Sanelli JA, Cergol KM, Dryza V, Payne RJ, Bieske EJ, Radom L, Schmidt TW. Hydrogen-adduction to open-shell graphene fragments: spectroscopy, thermochemistry and astrochemistry. Chem Sci 2017; 8:1186-1194. [PMID: 28451259 PMCID: PMC5369534 DOI: 10.1039/c6sc03787a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 09/24/2016] [Indexed: 11/25/2022] Open
Abstract
We apply a combination of state-of-the-art experimental and quantum-chemical methods to elucidate the electronic and chemical energetics of hydrogen adduction to a model open-shell graphene fragment. The lowest-energy adduct, 1H-phenalene, is determined to have a bond dissociation energy of 258.1 kJ mol-1, while other isomers exhibit reduced or in some cases negative bond dissociation energies, the metastable species being bound by the emergence of a conical intersection along the high-symmetry dissociation coordinate. The gas-phase excitation spectrum of 1H-phenalene and its radical cation are recorded using laser spectroscopy coupled to mass-spectrometry. Several electronically excited states of both species are observed, allowing the determination of the excited-state bond dissociation energy. The ionization energy of 1H-phenalene is determined to be 7.449(17) eV, consistent with high-level W1X-2 calculations.
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Affiliation(s)
- Gerard D O'Connor
- School of Chemistry , UNSW Sydney , NSW 2052 , Australia . ; Tel: +61 439 386 109
| | - Bun Chan
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia
- Graduate School of Engineering , Nagasaki University , Bunkyo 1-14 , Nagasaki 852-8521 , Japan
| | - Julian A Sanelli
- School of Chemistry , The University of Melbourne , Victoria 3010 , Australia
| | - Katie M Cergol
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Viktoras Dryza
- School of Chemistry , The University of Melbourne , Victoria 3010 , Australia
| | - Richard J Payne
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Evan J Bieske
- School of Chemistry , The University of Melbourne , Victoria 3010 , Australia
| | - Leo Radom
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Timothy W Schmidt
- School of Chemistry , UNSW Sydney , NSW 2052 , Australia . ; Tel: +61 439 386 109
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11
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Lee YR, Park CB, Hwang J, Sung BJ, Kim HL, Kwon CH. Observation of the Ring-Puckering Vibrational Mode in Thietane Cation. J Phys Chem A 2017; 121:1163-1167. [DOI: 10.1021/acs.jpca.6b12724] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yu Ran Lee
- Department
of Chemistry and Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Korea
| | - Chung Bin Park
- Department
of Chemistry, Sogang University, Seoul 04107, Korea
| | - Jiye Hwang
- Department
of Chemistry, Sogang University, Seoul 04107, Korea
| | - Bong June Sung
- Department
of Chemistry, Sogang University, Seoul 04107, Korea
| | - Hong Lae Kim
- Department
of Chemistry and Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Korea
| | - Chan Ho Kwon
- Department
of Chemistry and Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Korea
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12
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Garcia RL, Nieuwjaer N, Desfrançois C, Lecomte F, Leite SD, Manil B, Broquier M, Grégoire G. Vibronic spectra of protonated hydroxypyridines: contributions of prefulvenic and planar structures. Phys Chem Chem Phys 2017; 19:8258-8268. [DOI: 10.1039/c6cp08623c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The UV photofragmentation spectra of cold protonated hydroxypyridines display well resolved vibrational structures, interpreted with calculations at the CC2 level.
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Affiliation(s)
- R. Lozada Garcia
- Laboratoire de Physique des Lasers
- CNRS
- Université Paris 13
- Sorbonne Paris Cité
- France
| | - N. Nieuwjaer
- Laboratoire de Physique des Lasers
- CNRS
- Université Paris 13
- Sorbonne Paris Cité
- France
| | - C. Desfrançois
- Laboratoire de Physique des Lasers
- CNRS
- Université Paris 13
- Sorbonne Paris Cité
- France
| | - F. Lecomte
- Laboratoire de Physique des Lasers
- CNRS
- Université Paris 13
- Sorbonne Paris Cité
- France
| | - S. D. Leite
- Laboratoire de Physique des Lasers
- CNRS
- Université Paris 13
- Sorbonne Paris Cité
- France
| | - B. Manil
- Laboratoire de Physique des Lasers
- CNRS
- Université Paris 13
- Sorbonne Paris Cité
- France
| | - M. Broquier
- Institut des Sciences Moléculaires d'Orsay (ISMO)
- CNRS
- Univ. Paris Sud
- Université Paris-Saclay
- F-91405 Orsay
| | - G. Grégoire
- Institut des Sciences Moléculaires d'Orsay (ISMO)
- CNRS
- Univ. Paris Sud
- Université Paris-Saclay
- F-91405 Orsay
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13
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Moore PW, Hooker JP, Zavras A, Khairallah GN, Krenske EH, Bernhardt PV, Quach G, Moore EG, O'Hair RAJ, Williams CM. Hydroxyl Radicals via Collision-Induced Dissociation of Trimethylammonium Benzyl Alcohols. Aust J Chem 2017. [DOI: 10.1071/ch16602] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The hydroxyl radical is a well known reactive oxygen species important for interstellar, atmospheric, and combustion chemistry in addition to multiple biochemical processes. Although there are many methods to generate the hydroxyl radical, most of these are inorganic based, with only a few originating from organic precursor molecules. Reported herein is the observation that trimethylammonium benzyl alcohols and their corresponding deuterated isotopologues act as a good source of hydroxyl and deuteroxyl radicals in the gas-phase under collision-induced dissociation (CID) conditions. Attempts to replicate this chemistry in the condensed phase are described.
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14
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Pino GA, Feraud G, Broquier M, Grégoire G, Soorkia S, Dedonder C, Jouvet C. Non-radiative processes in protonated diazines, pyrimidine bases and an aromatic azine. Phys Chem Chem Phys 2016; 18:20126-34. [PMID: 27110833 DOI: 10.1039/c6cp01345g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The excited state lifetimes of DNA bases are often very short due to very efficient non-radiative processes assigned to the ππ*-nπ* coupling. A set of protonated aromatic diazine molecules (pyridazine, pyrimidine and pyrazine C4H5N2(+)) and protonated pyrimidine DNA bases (cytosine, uracil and thymine), as well as the protonated pyridine (C5H6N(+)), have been investigated. For all these molecules except one tautomer of protonated uracil (enol-keto), electronic spectroscopy exhibits vibrational line broadening. Excited state geometry optimization at the CC2 level has been conducted to find out whether the excited state lifetimes measured from line broadening can be correlated to the calculated ordering of the ππ* and nπ* states and the ππ*-nπ* energy gap. The short lifetimes, observed when one nitrogen atom of the ring is not protonated, can be rationalized by relaxation of the ππ* state to the nπ* state or directly to the electronic ground state through ring puckering.
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Affiliation(s)
- Gustavo A Pino
- Instituto de Investigaciones en Físico Química de Córdoba (INFIQC) CONICET - UNC. Dpto. de Fisicoquímica - Facultad de Ciencias Químicas - Centro Láser de Ciencias Moleculares - Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba, Argentina
| | - Géraldine Feraud
- CNRS, Aix Marseille Université, PIIM UMR 7345, 13397, Marseille, France.
| | - Michel Broquier
- Centre Laser de l'Université Paris-Sud (CLUPS/LUMAT), Univ. Paris-Sud, CNRS, IOGS, Université Paris-Saclay, F-91405 Orsay, France and Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris Sud, Université Paris-Saclay, F-91405 Orsay, France
| | - Gilles Grégoire
- Centre Laser de l'Université Paris-Sud (CLUPS/LUMAT), Univ. Paris-Sud, CNRS, IOGS, Université Paris-Saclay, F-91405 Orsay, France and Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris Sud, Université Paris-Saclay, F-91405 Orsay, France
| | - Satchin Soorkia
- Centre Laser de l'Université Paris-Sud (CLUPS/LUMAT), Univ. Paris-Sud, CNRS, IOGS, Université Paris-Saclay, F-91405 Orsay, France and Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris Sud, Université Paris-Saclay, F-91405 Orsay, France
| | - Claude Dedonder
- CNRS, Aix Marseille Université, PIIM UMR 7345, 13397, Marseille, France.
| | - Christophe Jouvet
- CNRS, Aix Marseille Université, PIIM UMR 7345, 13397, Marseille, France.
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15
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O’Connor GD, Sanelli JA, Dryza V, Bieske EJ, Schmidt TW. Electronic spectrum of 9-methylanthracenium radical cation. J Chem Phys 2016; 144:154303. [DOI: 10.1063/1.4945109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Julian A. Sanelli
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Vik Dryza
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Evan J. Bieske
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
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16
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Esteves-López N, Dedonder-Lardeux C, Jouvet C. Excited state of protonated benzene and toluene. J Chem Phys 2015; 143:074303. [DOI: 10.1063/1.4928692] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Natalia Esteves-López
- Aix-Marseille Université, CNRS, UMR-7345, Physique des Interactions Ioniques et Moléculaires (PIIM), Marseille, France
| | - Claude Dedonder-Lardeux
- Aix-Marseille Université, CNRS, UMR-7345, Physique des Interactions Ioniques et Moléculaires (PIIM), Marseille, France
| | - Christophe Jouvet
- Aix-Marseille Université, CNRS, UMR-7345, Physique des Interactions Ioniques et Moléculaires (PIIM), Marseille, France
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17
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Hansen CS, Blanksby SJ, Trevitt AJ. Ultraviolet photodissociation action spectroscopy of gas-phase protonated quinoline and isoquinoline cations. Phys Chem Chem Phys 2015; 17:25882-90. [DOI: 10.1039/c5cp02035b] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gas-phase two-photon UV action spectra of protonated quinoline and isoquinoline cations are reported revealing two broad, vibrationally-structured electronic bands and multiple photoproduct channels.
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Affiliation(s)
| | - Stephen J. Blanksby
- Central Analytical Research Facility
- Queensland University of Technology
- Australia
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