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Abma G, Parkes MA, Horke DA. Preparation of Tautomer-Pure Molecular Beams by Electrostatic Deflection. J Phys Chem Lett 2024; 15:4587-4592. [PMID: 38656191 PMCID: PMC11071072 DOI: 10.1021/acs.jpclett.4c00768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/09/2024] [Accepted: 04/10/2024] [Indexed: 04/26/2024]
Abstract
Tautomers are ubiquitous throughout chemistry and typically considered inseparable in solution. Yet (bio)chemical activity is highly tautomer-specific, with common examples being the amino and nucleic acids. While tautomers exist in an equilibrium in solution, in the cold environment of a molecular beam the barrier to tautomerization is typically much too high for interconversion, and tautomers can be considered separate species. Here we demonstrate the first separation of tautomers within a molecular beam and the production of tautomerically pure gas-phase samples. We show this for the 2-pyridone/2-hydroxypyridine system, an important structural motif in both uracil and cytosine. Spatial separation of the tautomers is achieved via electrostatic deflection in strong inhomogeneous fields. We furthermore collect tautomer-resolved photoelectron spectra using femtosecond multiphoton ionization. This paves the way for studying the structure-function-dynamic relationship on the level of individual tautomers, using approaches that typically lack the resolution to do so, such as ultrafast dynamics experiments.
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Affiliation(s)
- Grite
L. Abma
- Radboud
University, Institute for Molecules
and Materials, Heyendaalseweg
135, 6525 AJ Nijmegen, The Netherlands
| | - Michael A. Parkes
- Department
of Chemistry, University College London, 20 Gordon Street, WC1H 0AJ London, United Kingdom
| | - Daniel A. Horke
- Radboud
University, Institute for Molecules
and Materials, Heyendaalseweg
135, 6525 AJ Nijmegen, The Netherlands
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2
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Feng B, Yang D, He Z, Fang B, Wu G, Yang X. Excitation Energy-Dependent Decay Dynamics of the S 1 State of N-Methyl-2-pyridone. J Phys Chem A 2023; 127:10139-10146. [PMID: 38058157 DOI: 10.1021/acs.jpca.3c05745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
The UV-induced decay dynamics of N-methyl-2-pyridone is investigated using a femtosecond time-resolved photoelectron spectroscopy method. Irradiation in the wavelength range of 339.3-258.9 nm prepares N-methyl-2-pyridone molecules with very different vibrational levels of the S1(11ππ*) state. For v' = 0 (origin) and a few low-energy vibrational levels slightly above the S1 state origin, the radiative decay channel is in operation for some specific vibrations. This is revealed by the excited-state lifetime of ≫1 ns. In addition, some other nearby S1 vibronic states have a much shorter lifetime in the range of several picoseconds to a few tens of picoseconds, indicating that the radiation-less decay to the ground state (S0) via internal conversion is the dominant channel for them. As the pump wavelength slightly decreases, the radiative decay is suddenly not important at all, and the deactivation rate of the S1 state becomes faster. At shorter pump wavelengths, the lifetime of highly excited vibrational states of the S1 state further decreases with the increase in the vibrational excess energy. This study provides quantitative information about the excitation energy-dependent decay dynamics of the S1 state of N-methyl-2-pyridone. Methyl substitution effects on the excited-state dynamics of 2-pyridone are also discussed.
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Affiliation(s)
- Baihui Feng
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China
- Key Laboratory of Chemical Lasers, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dongyuan Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China
| | - Zhigang He
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China
| | - Benjie Fang
- Key Laboratory of Chemical Lasers, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China
| | - Guorong Wu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China
- Department of Chemistry, College of Science, Southern University of Science and Technology, Shenzhen 518055, China
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3
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Yang D, Min Y, Feng B, Yang X, Wu G. Vibrational-state dependent decay dynamics of 2-pyridone excited to the S 1 electronic state. Phys Chem Chem Phys 2022; 24:22710-22715. [PMID: 36106839 DOI: 10.1039/d2cp03279a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The S1(1ππ*) state decay dynamics of 2-pyridone excited around the 000 band origin is investigated using femtosecond time-resolved photoelectron imaging technique. At a pump wavelength of 334.0 nm, the vibrational ground state and a few low energy vibrational states covered by the bandwidth of the pump laser pulses are excited. The lifetimes of the vibrational states show strong dependence on the vibrational energy and mode. A quantum beat between two lowest energy vibrational states is also observed. This study provides quantitative information about the vibrational-state dependent lifetime of the S1 state of 2-pyridone.
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Affiliation(s)
- Dongyuan Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China.
| | - Yanjun Min
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baihui Feng
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China. .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China. .,Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Guorong Wu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China.
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4
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5
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Zhang YR, Yuan DF, Qian CH, Wang LS. Observation of a dipole-bound excited state in 4-ethynylphenoxide and comparison with the quadrupole-bound excited state in the isoelectronic 4-cyanophenoxide. J Chem Phys 2021; 155:124305. [PMID: 34598564 DOI: 10.1063/5.0065510] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Negative ions do not possess Rydberg states but can have Rydberg-like nonvalence excited states near the electron detachment threshold, including dipole-bound states (DBSs) and quadrupole-bound states (QBSs). While DBSs have been studied extensively, quadrupole-bound excited states have been more rarely observed. 4-cyanophenoxide (4CP-) was the first anion observed to possess a quadrupole-bound exited state 20 cm-1 below its detachment threshold. Here, we report the observation of a DBS in the isoelectronic 4-ethynylphenoxide anion (4EP-), providing a rare opportunity to compare the behaviors of a dipole-bound and a quadrupole-bound excited state in a pair of very similar anions. Photodetachment spectroscopy (PDS) of cryogenically cooled 4EP- reveals a DBS 76 cm-1 below its detachment threshold. Photoelectron spectroscopy (PES) at 266 nm shows that the electronic structure of 4EP- and 4CP- is nearly identical. The observed vibrational features in both the PDS and PES, as well as autodetachment from the nonvalence excited states, are also found to be similar for both anions. However, resonant two-photon detachment (R2PD) from the bound vibrational ground state is observed to be very different for the DBS in 4EP- and the QBS in 4CP-. The R2PD spectra reveal that decays take place from both the DBS and QBS to the respective anion ground electronic states within the 5 ns detachment laser pulse due to internal conversion followed by intramolecular vibrational redistribution and relaxation, but the decay mechanisms appear to be very different. In the R2PD spectrum of 4EP-, we observe strong threshold electron signals, which are due to detachment, by the second photon, of highly rotationally excited anions resulted from the decay of the DBS. On the other hand, in the R2PD spectrum of 4CP-, we observe well-resolved vibrational peaks due to the three lowest-frequency vibrational modes of 4CP-, which are populated from the decay of the QBS. The different behaviors of the R2PD spectra suggest unexpected differences between the relaxation mechanisms of the dipole-bound and quadrupole-bound excited states.
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Affiliation(s)
- Yue-Rou Zhang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Dao-Fu Yuan
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Chen-Hui Qian
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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6
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Phelps R, Orr-Ewing AJ. Direct Observation of Ylide and Enol Intermediates Formed in Competition with Wolff Rearrangement of Photoexcited Ethyl Diazoacetoacetate. J Am Chem Soc 2020; 142:7836-7844. [PMID: 32267699 DOI: 10.1021/jacs.0c00752] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The photoexcitation of α-diazocarbonyl compounds produces ketenes by both concerted and stepwise Wolff rearrangements. The stepwise mechanism proceeds through singlet carbene intermediates which can also participate in bimolecular reactions such as ylide formation with nucleophiles. Here, ultrafast transient infrared absorption spectroscopy is used to show competitive production of singlet carbene and ketene intermediates from the photoexcitation of ethyl diazoacetoacetate. We provide direct spectroscopic evidence for ylide formation by singlet α-carbonyl carbene capture in aprotic nucleophilic solvents (with ylide bands at 1625 cm-1 in acetonitrile and 1586 and 1635 cm-1 in tetrahydrofuran) and report an enol-mediated pathway for singlet α-carbonyl carbene reaction with alcohols (ethanol or tert-butanol) identified by an absorption band at 1694 cm-1; however, we find no evidence for a previously proposed ylide pathway. The α-carbonyl carbene is monitored by using a band with solvent-dependent wavenumber in the range 1627-1645 cm-1. A computed two-dimensional cut of the potential energy surface for the reaction of the singlet α-carbonyl carbene with methanol shows that the enol forms without a barrier and that this reaction is promoted by an intermolecular hydrogen bond from methanol to the carbonyl oxygen atom. The corresponding ylide structure lies higher in energy, with a barrierless downhill path to isomerization to the enol.
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Affiliation(s)
- Ryan Phelps
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
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7
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Siffert L, Blaser S, Ottiger P, Leutwyler S. Transition from Water Wires to Bifurcated H-Bond Networks in 2-Pyridone·(H2O)n, n = 1–4 Clusters. J Phys Chem A 2018; 122:9285-9297. [DOI: 10.1021/acs.jpca.8b09410] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Luca Siffert
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Susan Blaser
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Philipp Ottiger
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Samuel Leutwyler
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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8
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Kijak M, Peukert S, Mengesha E, Sepioł J, Gil M. Supersonic Jet Spectroscopy and Density Functional Theory Study of Isomeric Diazines: 1,4- and 1,8-Diazatriphenylene. Why Do They Differ So Deeply? J Phys Chem A 2016; 120:7817-7827. [DOI: 10.1021/acs.jpca.6b06475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michał Kijak
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, PL-01-224 Warsaw, Poland
| | - Sebastian Peukert
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, PL-01-224 Warsaw, Poland
| | - Ephriem Mengesha
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, PL-01-224 Warsaw, Poland
| | - Jerzy Sepioł
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, PL-01-224 Warsaw, Poland
| | - Michał Gil
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, PL-01-224 Warsaw, Poland
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9
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Shterev IG, Delchev VB. Excited-state deactivation channels via internal conversions in two position isomers of hydroxy-methyl-pyridine: a theoretical study. J PHYS ORG CHEM 2015. [DOI: 10.1002/poc.3471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Ivan G. Shterev
- Department Inorganic and Physical Chemistry; University of Food Technologies; 4002 Plovdiv Bulgaria
| | - Vassil B. Delchev
- Department of Physical Chemistry; University of Plovdiv; 4000 Plovdiv Bulgaria
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10
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Lobsiger S, Trachsel MA, Den T, Leutwyler S. Excited-State Structure, Vibrations, and Nonradiative Relaxation of Jet-Cooled 5-Fluorocytosine. J Phys Chem B 2014; 118:2973-84. [DOI: 10.1021/jp500410s] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Simon Lobsiger
- Department of Chemistry and
Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Maria A. Trachsel
- Department of Chemistry and
Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Takuya Den
- Department of Chemistry and
Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Samuel Leutwyler
- Department of Chemistry and
Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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11
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Frey JA, Ottiger P, Leutwyler S. Watson–Crick and Sugar-Edge Base Pairing of Cytosine in the Gas Phase: UV and Infrared Spectra of Cytosine·2-Pyridone. J Phys Chem B 2014; 118:682-91. [DOI: 10.1021/jp409660b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jann A. Frey
- Department
of Chemistry and
Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Philipp Ottiger
- Department
of Chemistry and
Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Samuel Leutwyler
- Department
of Chemistry and
Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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12
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Beg H, Das D, Ash S, Misra A. Computation of polarizability, hyper-polarizability and hardness as descriptor for enol–keto tautomerizations of 2-hydroxy pyridines. COMPUT THEOR CHEM 2013. [DOI: 10.1016/j.comptc.2013.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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Lobsiger S, Trachsel MA, Frey HM, Leutwyler S. Excited-State Structure and Dynamics of Keto–Amino Cytosine: The 1ππ* State Is Nonplanar and Its Radiationless Decay Is Not Ultrafast. J Phys Chem B 2013; 117:6106-15. [DOI: 10.1021/jp401881b] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Simon Lobsiger
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Maria A. Trachsel
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Hans-Martin Frey
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Samuel Leutwyler
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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14
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Winter NOC, Graf NK, Leutwyler S, Hättig C. Benchmarks for 0–0 transitions of aromatic organic molecules: DFT/B3LYP, ADC(2), CC2, SOS-CC2 and SCS-CC2 compared to high-resolution gas-phase data. Phys Chem Chem Phys 2013; 15:6623-30. [DOI: 10.1039/c2cp42694c] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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15
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Ottiger P, Leutwyler S, Köppel H. Vibrational quenching of excitonic splittings in H-bonded molecular dimers: the electronic Davydov splittings cannot match experiment. J Chem Phys 2012; 136:174308. [PMID: 22583231 DOI: 10.1063/1.4705119] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The S(1)/S(2) state exciton splittings of symmetric doubly hydrogen-bonded gas-phase dimers provide spectroscopic benchmarks for the excited-state electronic couplings between UV chromophores. These have important implications for electronic energy transfer in multichromophoric systems ranging from photosynthetic light-harvesting antennae to photosynthetic reaction centers, conjugated polymers, molecular crystals, and nucleic acids. We provide laser spectroscopic data on the S(1)/S(2) excitonic splitting Δ(exp) of the doubly H-bonded o-cyanophenol (oCP) dimer and compare to the splittings of the dimers of (2-aminopyridine)(2), [(2AP)(2)], (2-pyridone)(2), [(2PY)(2)], (benzoic acid)(2), [(BZA)(2)], and (benzonitrile)(2), [(BN)(2)]. The experimental S(1)/S(2) excitonic splittings are Δ(exp) = 16.4 cm(-1) for (oCP)(2), 11.5 cm(-1) for (2AP)(2), 43.5 cm(-1) for (2PY)(2), and <1 cm(-1) for (BZA)(2). In contrast, the vertical S(1)/S(2) energy gaps Δ(calc) calculated by the approximate second-order coupled cluster (CC2) method for the same dimers are 10-40 times larger than the Δ(exp) values. The qualitative failure of this and other ab initio methods to reproduce the exciton splitting Δ(exp) arises from the Born-Oppenheimer (BO) approximation, which implicitly assumes the strong-coupling case and cannot be employed to evaluate excitonic splittings of systems that are in the weak-coupling limit. Given typical H-bond distances and oscillator strengths, the majority of H-bonded dimers lie in the weak-coupling limit. In this case, the monomer electronic-vibrational coupling upon electronic excitation must be accounted for; the excitonic splittings arise between the vibronic (and not the electronic) transitions. The discrepancy between the BO-based splittings Δ(calc) and the much smaller experimental Δ(exp) values is resolved by taking into account the quenching of the BO splitting by the intramolecular vibronic coupling in the monomer S(1) ← S(0) excitation. The vibrational quenching factors Γ for the five dimers (oCP)(2), (2AP)(2), (2AP)(2), (BN)(2), and (BZA)(2) lie in the range Γ = 0.03-0.2. The quenched excitonic splittings Γ[middle dot]Δ(calc) are found to be in very good agreement with the observed splittings Δ(exp). The vibrational quenching approach predicts reliable Δ(exp) values for the investigated dimers, confirms the importance of vibrational quenching of the electronic Davydov splittings, and provides a sound basis for predicting realistic exciton splittings in multichromophoric systems.
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Affiliation(s)
- Philipp Ottiger
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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16
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Trachsel MA, Lobsiger S, Leutwyler S. Out-of-Plane Low-Frequency Vibrations and Nonradiative Decay in the 1ππ* State of Jet-Cooled 5-Methylcytosine. J Phys Chem B 2012; 116:11081-91. [DOI: 10.1021/jp305688m] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Maria A. Trachsel
- Department of Chemistry
and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Simon Lobsiger
- Department of Chemistry
and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Samuel Leutwyler
- Department of Chemistry
and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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17
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Heid CG, Ottiger P, Leist R, Leutwyler S. The S1/S2 exciton interaction in 2-pyridone·6-methyl-2-pyridone: Davydov splitting, vibronic coupling, and vibronic quenching. J Chem Phys 2012; 135:154311. [PMID: 22029317 DOI: 10.1063/1.3652759] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The excitonic splitting between the S(1) and S(2) electronic states of the doubly hydrogen-bonded dimer 2-pyridone[middle dot]6-methyl-2-pyridone (2PY·6M2PY) is studied in a supersonic jet, applying two-color resonant two-photon ionization (2C-R2PI), UV-UV depletion, and dispersed fluorescence spectroscopies. In contrast to the C(2h) symmetric (2-pyridone)(2) homodimer, in which the S(1) ← S(0) transition is symmetry-forbidden but the S(2) ← S(0) transition is allowed, the symmetry-breaking by the additional methyl group in 2PY·6M2PY leads to the appearance of both the S(1) and S(2) origins, which are separated by Δ(exp) = 154 cm(-1). When combined with the separation of the S(1) ← S(0) excitations of 6M2PY and 2PY, which is δ = 102 cm(-1), one obtains an S(1)/S(2) exciton coupling matrix element of V(AB, el) = 57 cm(-1) in a Frenkel-Davydov exciton model. The vibronic couplings in the S(1)/S(2) ← S(0) spectrum of 2PY·6M2PY are treated by the Fulton-Gouterman single-mode model. We consider independent couplings to the intramolecular 6a(') vibration and to the intermolecular σ(') stretch, and obtain a semi-quantitative fit to the observed spectrum. The dimensionless excitonic couplings are C(6a(')) = 0.15 and C(σ(')) = 0.05, which places this dimer in the weak-coupling limit. However, the S(1)/S(2) state exciton splittings Δ(calc) calculated by the configuration interaction singles method (CIS), time-dependent Hartree-Fock (TD-HF), and approximate second-order coupled-cluster method (CC2) are between 1100 and 1450 cm(-1), or seven to nine times larger than observed. These huge errors result from the neglect of the coupling to the optically active intra- and intermolecular vibrations of the dimer, which lead to vibronic quenching of the purely electronic excitonic splitting. For 2PY·6M2PY the electronic splitting is quenched by a factor of ~30 (i.e., the vibronic quenching factor is Γ(exp) = 0.035), which brings the calculated splittings into close agreement with the experimentally observed value. The 2C-R2PI and fluorescence spectra of the tautomeric species 2-hydroxypyridine·6-methyl-2-pyridone (2HP·6M2PY) are also observed and assigned.
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Affiliation(s)
- Cornelia G Heid
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
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18
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Blaser S, Ottiger P, Lobsiger S, Frey HM, Leutwyler S. Intermolecular Clamping by Hydrogen Bonds: 2-Pyridone⋅NH3. Chemphyschem 2011; 12:1841-50. [DOI: 10.1002/cphc.201100037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Indexed: 11/09/2022]
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19
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Barbatti M, Aquino AJA, Szymczak JJ, Nachtigallová D, Lischka H. Photodynamical simulations of cytosine: characterization of the ultrafast bi-exponential UV deactivation. Phys Chem Chem Phys 2011; 13:6145-55. [DOI: 10.1039/c0cp01327g] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Time-dependent density functional theory study of the excited-state dihydrogen bonding: clusters of 2-pyridone with diethylmethylsilane and triethylgermanium. J Mol Model 2010; 17:1891-7. [DOI: 10.1007/s00894-010-0896-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2010] [Accepted: 11/03/2010] [Indexed: 12/01/2022]
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21
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Yang M, Szyc Ł, Dreyer J, Nibbering ETJ, Elsaesser T. The Hydrogen-Bonded 2-Pyridone Dimer Model System. 2. Femtosecond Mid-Infrared Pump−Probe Study. J Phys Chem A 2010; 114:12195-201. [PMID: 21038900 DOI: 10.1021/jp108096y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Ming Yang
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, D-12489 Berlin, Germany
| | - Łukasz Szyc
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, D-12489 Berlin, Germany
| | - Jens Dreyer
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, D-12489 Berlin, Germany
| | - Erik T. J. Nibbering
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, D-12489 Berlin, Germany
| | - Thomas Elsaesser
- Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, D-12489 Berlin, Germany
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22
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Sagvolden E, Furche F. Is There Symmetry Breaking in the First Excited Singlet State of 2-Pyridone Dimer? J Phys Chem A 2010; 114:6897-903. [DOI: 10.1021/jp102637e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Espen Sagvolden
- University of California, Irvine, Department of Chemistry, 1102 Natural Sciences II, Irvine California 92697-2025
| | - Filipp Furche
- University of California, Irvine, Department of Chemistry, 1102 Natural Sciences II, Irvine California 92697-2025
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23
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Poully JC, Schermann JP, Nieuwjaer N, Lecomte F, Grégoire G, Desfrançois C, Garcia GA, Nahon L, Nandi D, Poisson L, Hochlaf M. Photoionization of 2-pyridone and 2-hydroxypyridine. Phys Chem Chem Phys 2010; 12:3566-72. [DOI: 10.1039/b923630a] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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24
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Pfaffen C, Frey HM, Ottiger P, Leutwyler S, Bachorz RA, Klopper W. Large-amplitude vibrations of an N–H⋯π hydrogen bonded cis-amide–benzene complex. Phys Chem Chem Phys 2010; 12:8208-18. [DOI: 10.1039/c002056g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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25
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Lobsiger S, Frey HM, Leutwyler S. Supersonic jet UV spectrum and nonradiative processes of the thymine analogue 5-methyl-2-hydroxypyrimidine. Phys Chem Chem Phys 2010; 12:5032-40. [DOI: 10.1039/b924395j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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26
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Szymczak JJ, Barbatti M, Soo Hoo JT, Adkins JA, Windus TL, Nachtigallová D, Lischka H. Photodynamics Simulations of Thymine: Relaxation into the First Excited Singlet State. J Phys Chem A 2009; 113:12686-93. [DOI: 10.1021/jp905085x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jaroslaw J. Szymczak
- Institute for Theoretical Chemistry, University of Vienna, Waehrinegrstrasse 17, A 1090 Vienna, Austria, Departments of Physics, Siena College, 515 Loudon Road, Loudonville, New York 12211, Department of Chemistry, Northwest Missouri State University, 800 University Drive, Maryville, Missouri 64468, Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, Iowa 50011, and Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-16610
| | - Mario Barbatti
- Institute for Theoretical Chemistry, University of Vienna, Waehrinegrstrasse 17, A 1090 Vienna, Austria, Departments of Physics, Siena College, 515 Loudon Road, Loudonville, New York 12211, Department of Chemistry, Northwest Missouri State University, 800 University Drive, Maryville, Missouri 64468, Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, Iowa 50011, and Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-16610
| | - Jason T. Soo Hoo
- Institute for Theoretical Chemistry, University of Vienna, Waehrinegrstrasse 17, A 1090 Vienna, Austria, Departments of Physics, Siena College, 515 Loudon Road, Loudonville, New York 12211, Department of Chemistry, Northwest Missouri State University, 800 University Drive, Maryville, Missouri 64468, Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, Iowa 50011, and Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-16610
| | - Jaclyn A. Adkins
- Institute for Theoretical Chemistry, University of Vienna, Waehrinegrstrasse 17, A 1090 Vienna, Austria, Departments of Physics, Siena College, 515 Loudon Road, Loudonville, New York 12211, Department of Chemistry, Northwest Missouri State University, 800 University Drive, Maryville, Missouri 64468, Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, Iowa 50011, and Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-16610
| | - Theresa L. Windus
- Institute for Theoretical Chemistry, University of Vienna, Waehrinegrstrasse 17, A 1090 Vienna, Austria, Departments of Physics, Siena College, 515 Loudon Road, Loudonville, New York 12211, Department of Chemistry, Northwest Missouri State University, 800 University Drive, Maryville, Missouri 64468, Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, Iowa 50011, and Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-16610
| | - Dana Nachtigallová
- Institute for Theoretical Chemistry, University of Vienna, Waehrinegrstrasse 17, A 1090 Vienna, Austria, Departments of Physics, Siena College, 515 Loudon Road, Loudonville, New York 12211, Department of Chemistry, Northwest Missouri State University, 800 University Drive, Maryville, Missouri 64468, Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, Iowa 50011, and Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-16610
| | - Hans Lischka
- Institute for Theoretical Chemistry, University of Vienna, Waehrinegrstrasse 17, A 1090 Vienna, Austria, Departments of Physics, Siena College, 515 Loudon Road, Loudonville, New York 12211, Department of Chemistry, Northwest Missouri State University, 800 University Drive, Maryville, Missouri 64468, Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, Iowa 50011, and Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-16610
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27
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Ottiger P, Frey JA, Frey HM, Leutwyler S. Jet-Cooled 2-Aminopyridine Dimer: Conformers and Infrared Vibrational Spectra. J Phys Chem A 2009; 113:5280-8. [DOI: 10.1021/jp811359k] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Philipp Ottiger
- Departement für Chemie and Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Jann A. Frey
- Departement für Chemie and Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Hans-Martin Frey
- Departement für Chemie and Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Samuel Leutwyler
- Departement für Chemie and Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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28
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Sonnenberg JL, Wong KF, Voth GA, Schlegel HB. Distributed Gaussian Valence Bond Surface Derived from Ab Initio Calculations. J Chem Theory Comput 2009; 5:949-61. [DOI: 10.1021/ct800477y] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Jason L. Sonnenberg
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, and Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - Kim F. Wong
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, and Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - Gregory A. Voth
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, and Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - H. Bernhard Schlegel
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, and Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
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30
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Nonadiabatic Excited-State Dynamics of Aromatic Heterocycles: Toward the Time-Resolved Simulation of Nucleobases. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/978-1-4020-8184-2_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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31
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Barbatti M, Ruckenbauer M, Szymczak JJ, Aquino AJA, Lischka H. Nonadiabatic excited-state dynamics of polar π-systems and related model compounds of biological relevance. Phys Chem Chem Phys 2008; 10:482-94. [DOI: 10.1039/b709315m] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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32
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Bachorz RA, Bischoff FA, Höfener S, Klopper W, Ottiger P, Leist R, Frey JA, Leutwyler S. Scope and limitations of the SCS-MP2 method for stacking and hydrogen bonding interactions. Phys Chem Chem Phys 2008; 10:2758-66. [DOI: 10.1039/b718494h] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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33
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Leist R, Frey J, Ottiger P, Frey HM, Leutwyler S, Bachorz R, Klopper W. Nucleobase–Fluorobenzene Interactions: Hydrogen Bonding Wins over π Stacking. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200701171] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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34
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Leist R, Frey JA, Ottiger P, Frey HM, Leutwyler S, Bachorz RA, Klopper W. Nucleobase–Fluorobenzene Interactions: Hydrogen Bonding Wins over π Stacking. Angew Chem Int Ed Engl 2007; 46:7449-52. [PMID: 17722215 DOI: 10.1002/anie.200701171] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Roman Leist
- Department of Chemistry and Biochemistry, Universität Bern, Freiestrasse 3, 3012 Bern, Switzerland
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35
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Brause R, Schmitt M, Kleinermanns K. Improved Determination of Structural Changes of 2-Pyridone-(H2O)1 upon Electronic Excitation. J Phys Chem A 2007; 111:3287-93. [PMID: 17419594 DOI: 10.1021/jp067572b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The change of the 2-pyridone-water cluster (2PYH(2)O) structure upon electronic excitation is determined by a Franck-Condon analysis of the intensities in the fluorescence emission spectra obtained via excitation of three different vibronic bands as well as a structural fit based on the rotational constants of eight isotopomers that have been reported by Held and Pratt (J. Am. Chem. Soc., 1993, 115, 9708]. A total of 93 emission band intensities were fit, together with the changes of rotational constants of 8 isotopomers. The geometry change upon electronic excitation to the pipi* state can be described by a strong and unsymmetrical elongation of the hydrogen bonds, a contraction of the OH bond involved in the cyclic cluster arrangement, and an unsymmetrical ring deformation. The resulting geometry changes are interpreted on the basis of ab initio calculations.
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Affiliation(s)
- Robert Brause
- Heinrich-Heine-Universität, Institut für Physikalische Chemie I, D-40225 Düsseldorf, Germany
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