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Vibrational study of acrylonitrile dimer and acrylonitrile-water hydrogen-bonded complexes in solid neon supported by ab initio calculations. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.133503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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2
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Uhlemann T, Seidel S, Müller CW. Laser desorption single-conformation UV and IR spectroscopy of the sulfonamide drug sulfanilamide, the sulfanilamide-water complex, and the sulfanilamide dimer. Phys Chem Chem Phys 2018; 19:14625-14640. [PMID: 28537284 DOI: 10.1039/c7cp01464c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We have studied the conformational preferences of the sulfonamide drug sulfanilamide, its dimer, and its monohydrated complex through laser desorption single-conformation UV and IR spectroscopy in a molecular beam. Based on potential energy curves for the inversion of the anilinic and the sulfonamide NH2 groups calculated at DFT level, we suggest that the zero-point level wave function of the sulfanilamide monomer is appreciably delocalized over all four conformer wells. The sulfanilamide dimer, and the monohydrated complex each exhibit a single isomer in the molecular beam. The isomeric structures of the sulfanilamide dimer and the monohydrated sulfanilamide complex were assigned based on their conformer-specific IR spectra in the NH and OH stretch region. Quantum Theory of Atoms in Molecules (QTAIM) analysis of the calculated electron density in the water complex suggests that the water molecule is bound side-on in a hydrogen bonding pocket, donating one O-HO[double bond, length as m-dash]S hydrogen bond and accepting two hydrogen bonds, a NHO and a CHO hydrogen bond. QTAIM analysis of the dimer electron density suggests that the Ci symmetry dimer structure exhibits two dominating N-HO[double bond, length as m-dash]S hydrogen bonds, and three weaker types of interactions: two CHO bonds, two CHN bonds, and a chalcogen OO interaction. Most interestingly, the molecular beam dimer structure closely resembles the R dimer unit - the dimer unit with the greatest interaction energy - of the α, γ, and δ crystal polymorphs. Interacting Quantum Atoms analysis provides evidence that the total intermolecular interaction in the dimer is dominated by the short-range exchange-correlation contribution.
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Affiliation(s)
- Thomas Uhlemann
- Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, D-44780 Bochum, Germany.
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3
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Uhlemann T, Seidel S, Müller CW. Site-specific binding of a water molecule to the sulfa drugs sulfamethoxazole and sulfisoxazole: a laser-desorption isomer-specific UV and IR study. Phys Chem Chem Phys 2018; 20:6891-6904. [DOI: 10.1039/c7cp08579f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Using isomer-specific IR spectroscopy, we show that sulfamethoxazole and sulfisoxazole exhibit distinct site specificities for binding a water molecule.
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Affiliation(s)
- Thomas Uhlemann
- Ruhr-Universität Bochum
- Fakultät für Chemie und Biochemie
- D-44780 Bochum
- Germany
| | - Sebastian Seidel
- Ruhr-Universität Bochum
- Fakultät für Chemie und Biochemie
- D-44780 Bochum
- Germany
| | - Christian W. Müller
- Ruhr-Universität Bochum
- Fakultät für Chemie und Biochemie
- D-44780 Bochum
- Germany
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4
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Min A, Ahn A, Moon CJ, Lee JH, Seong YG, Kim SK, Choi MY. Conformational structures of jet-cooled acetaminophen-water clusters: a gas phase spectroscopic and computational study. Phys Chem Chem Phys 2017; 19:4840-4848. [PMID: 28134364 DOI: 10.1039/c6cp06863d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Jet-cooled acetaminophen (AAP)-water clusters, AAP-(H2O)1, were investigated by mass-selected resonant two-photon ionization (R2PI), ultraviolet-ultraviolet hole-burning (UV-UV HB), infrared-dip (IR-dip), and infrared-ultraviolet hole-burning (IR-UV HB) spectroscopy. Each syn- and anti-AAP rotamer has three distinctive binding sites (-OH, >CO, and >NH) for a water molecule, thus 6 different AAP-(H2O)1 conformers are expected to exist in the molecular beam. The origin bands of the AAP(OH)-(H2O)1 and AAP(CO)-(H2O)1 conformers (including their syn- and anti-conformers) in the R2PI spectrum are shifted to red and blue compared to those of the AAP monomer, respectively. These frequency shifts upon complexation between a water molecule and a specific binding site of AAP are also predicted by theoretical calculations. The spectral assignments of the origin bands in the R2PI spectra and the IR vibrational bands in the IR-dip spectra of the four lowest-energy conformers of AAP-(H2O)1, [syn- and anti-AAP(OH)-(H2O)1 and syn- and anti-AAP(CO)-(H2O)1], are aided by ab initio and time-dependent density functional theory (TDDFT) calculations. Further investigation of the IR-dip spectra has revealed a hydrogen-bonded NH stretching mode, supporting the presence of the syn-AAP(NH)-(H2O)1 conformer. Moreover, by employing IR-UV HB spectroscopy, we have reconfirmed the existence of the syn-AAP(NH)-(H2O)1 conformer, which happened to be buried underneath the broad background contributed by the AAP(OH)-(H2O)1 conformers. These observations have led us to conclude that all of the possible conformers of AAP-(H2O)1 have been found in this study.
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Affiliation(s)
- Ahreum Min
- Department of Chemistry (BK21+) and Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea.
| | - Ahreum Ahn
- Department of Chemistry (BK21+) and Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea.
| | - Cheol Joo Moon
- Department of Chemistry (BK21+) and Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea.
| | - Ji Hoon Lee
- Department of Chemistry (BK21+) and Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea.
| | - Yeon Guk Seong
- Department of Chemistry (BK21+) and Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea.
| | - Seong Keun Kim
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea.
| | - Myong Yong Choi
- Department of Chemistry (BK21+) and Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Republic of Korea.
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5
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Rodrigues NDN, Staniforth M, Stavros VG. Photophysics of sunscreen molecules in the gas phase: a stepwise approach towards understanding and developing next-generation sunscreens. Proc Math Phys Eng Sci 2016; 472:20160677. [PMID: 27956888 PMCID: PMC5134319 DOI: 10.1098/rspa.2016.0677] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 10/24/2016] [Indexed: 12/22/2022] Open
Abstract
The relationship between exposure to ultraviolet (UV) radiation and skin cancer urges the need for extra photoprotection, which is presently provided by widespread commercially available sunscreen lotions. Apart from having a large absorption cross section in the UVA and UVB regions of the electromagnetic spectrum, the chemical absorbers in these photoprotective products should also be able to dissipate the excess energy in a safe way, i.e. without releasing photoproducts or inducing any further, harmful, photochemistry. While sunscreens are tested for both their photoprotective capability and dermatological compatibility, phenomena occurring at the molecular level upon absorption of UV radiation are largely overlooked. To date, there is only a limited amount of information regarding the photochemistry and photophysics of these sunscreen molecules. However, a thorough understanding of the intrinsic mechanisms by which popular sunscreen molecular constituents dissipate excess energy has the potential to aid in the design of more efficient, safer sunscreens. In this review, we explore the potential of using gas-phase frequency- and time-resolved spectroscopies in an effort to better understand the photoinduced excited-state dynamics, or photodynamics, of sunscreen molecules. Complementary computational studies are also briefly discussed. Finally, the future outlook of expanding these gas-phase studies into the solution phase is considered.
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6
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Dopfer O, Fujii M. Probing Solvation Dynamics around Aromatic and Biological Molecules at the Single-Molecular Level. Chem Rev 2016; 116:5432-63. [DOI: 10.1021/acs.chemrev.5b00610] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Otto Dopfer
- Institut
für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany
| | - Masaaki Fujii
- Laboratory
for Chemistry and Life Science, Tokyo Institute of Technology, Yokohama 226-8503, Japan
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7
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Ke H, Lisy JM. Influence of hydration on ion-biomolecule interactions: M(+)(indole)(H2O)(n) (M = Na, K; n = 3-6). Phys Chem Chem Phys 2015; 17:25354-64. [PMID: 26397000 DOI: 10.1039/c5cp01565k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The indole functional group can be found in many biologically relevant molecules, such as neurotransmitters, pineal hormones and medicines. Indole has been used as a tractable model to study the hydration structures of biomolecules as well as the interplay of non-covalent interactions within ion-biomolecule-water complexes, which largely determine their structure and dynamics. With three potential binding sites: above the six- or five-member ring, and the N-H group, the competition between π and hydrogen bond interactions involves multiple locations. Electrostatic interactions from monovalent cations are in direct competition with hydrogen bonding interactions, as structural configurations involving both direct cation-indole interactions and cation-water-indole bridging interactions were observed. The different charge densities of Na(+) and K(+) give rise to different structural conformers at the same level of hydration. Infrared spectra with parallel hybrid functional-based calculations and Gibbs free energy calculations revealed rich structural insights into the Na(+)/K(+)(indole)(H2O)3-6 cluster ion complexes. Isotopic (H/D) analyses were applied to decouple the spectral features originating from the OH and NH stretches. Results showed no evidence of direct interaction between water and the NH group of indole (via a σ-hydrogen bond) at current levels of hydration with the incorporation of cations. Hydrogen bonding to a π-system, however, was ubiquitous at hydration levels between two and five.
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Affiliation(s)
- Haochen Ke
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
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8
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Chaudret R, de Courcy B, Contreras-García J, Gloaguen E, Zehnacker-Rentien A, Mons M, Piquemal JP. Unraveling non-covalent interactions within flexible biomolecules: from electron density topology to gas phase spectroscopy. Phys Chem Chem Phys 2015; 16:9876-91. [PMID: 24419903 DOI: 10.1039/c3cp52774c] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The NCI (Non-Covalent Interactions) method, a recently-developed theoretical strategy to visualize weak non-covalent interactions from the topological analysis of the electron density and of its reduced gradient, is applied in the present paper to document intra- and inter-molecular interactions in flexible molecules and systems of biological interest in combination with IR spectroscopy. We first describe the conditions of application of the NCI method to the specific case of intramolecular interactions. Then we apply it to a series of stable conformations of isolated molecules as an interpretative technique to decipher the different physical interactions at play in these systems. Examples are chosen among neutral molecular systems exhibiting a large diversity of interactions, for which an extensive spectroscopic characterization under gas-phase isolation conditions has been obtained using state-of-the-art conformer-specific experimental techniques. The interactions presently documented range from weak intra-molecular H-bonds in simple amino-alcohols, to more complex patterns, with interactions of various strengths in model peptides, as well as in chiral bimolecular systems, where invaluable hints for the understanding of chiral recognition are revealed. We also provide a detailed technical appendix, which discusses the choices of cut-offs as well as the applicability of the NCI analysis to specific constrained systems, where local effects require attention. Finally, the NCI technique provides IR spectroscopists with an elegant visualization of the interactions that potentially impact their vibrational probes, namely the OH and NH stretching motions. This contribution illustrates the power and the conditions of use of the NCI technique, with the aim of providing an easy tool for all chemists, experimentalists and theoreticians, for the visualization and characterization of the interactions shaping complex molecular systems.
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Affiliation(s)
- R Chaudret
- Sorbonne Universités, UPMC, Laboratoire de Chimie Théorique and CNRS, UMR 7616, 75252 Paris Cedex 05, Paris, France.
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9
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Miyazaki M, Nakamura T, Wohlgemuth M, Mitrić R, Dopfer O, Fujii M. Single water solvation dynamics in the 4-aminobenzonitrile–water cluster cation revealed by picosecond time-resolved infrared spectroscopy. Phys Chem Chem Phys 2015; 17:29969-77. [DOI: 10.1039/c5cp05400a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The excess energy of photoionization can control the time scale of single water solvent orientation dynamics from picoseconds to infinitely long trapping in a local minimum.
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Affiliation(s)
- Mitsuhiko Miyazaki
- Chemical Resources Laboratory
- Tokyo Institute of Technology
- Yokohama 226-8503
- Japan
| | - Takashi Nakamura
- Chemical Resources Laboratory
- Tokyo Institute of Technology
- Yokohama 226-8503
- Japan
| | - Matthias Wohlgemuth
- Institut für Theoretische und Physikalische Chemie
- Julius-Maximilians-Universität Würzburg
- 97070 Würzburg
- Germany
| | - Roland Mitrić
- Institut für Theoretische und Physikalische Chemie
- Julius-Maximilians-Universität Würzburg
- 97070 Würzburg
- Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- 10623 Berlin
- Germany
| | - Masaaki Fujii
- Chemical Resources Laboratory
- Tokyo Institute of Technology
- Yokohama 226-8503
- Japan
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10
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Schmies M, Miyazaki M, Fujii M, Dopfer O. Microhydrated aromatic cluster cations: Binding motifs of 4-aminobenzonitrile-(H2O)n cluster cations with n ≤ 4. J Chem Phys 2014; 141:214301. [DOI: 10.1063/1.4901893] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Matthias Schmies
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Mitsuhiko Miyazaki
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Masaaki Fujii
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
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11
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Betz T, Zinn S, Graneek JB, Schnell M. Nuclear quadrupole coupling constants of two chemically distinct nitrogen atoms in 4-aminobenzonitrile. J Phys Chem A 2014; 118:5164-9. [PMID: 24911139 PMCID: PMC4106272 DOI: 10.1021/jp410964w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
![]()
The
rotational spectrum of 4-aminobenzonitrile in the gas phase
between 2 and 8.5 GHz is reported. Due to the two chemically distinct
nitrogen atoms, the observed transitions showed a rich hyperfine structure.
From the determination of the nuclear quadrupole coupling constants,
information about the electronic environment of these atoms could
be inferred. The results are compared to data for related molecules,
especially with respect to the absence of dual fluorescence in 4-aminobenzonitrile.
In addition, the two-photon ionization spectrum of this molecule was
recorded using a time-of-flight mass spectrometer integrated into
the setup. This new experimental apparatus is presented here for the
first time.
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Affiliation(s)
- Thomas Betz
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149, D-22761 Hamburg, Germany
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12
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Nakamura T, Schmies M, Patzer A, Miyazaki M, Ishiuchi SI, Weiler M, Dopfer O, Fujii M. Solvent Migration in Microhydrated Aromatic Aggregates: Ionization-Induced Site Switching in the 4-Aminobenzonitrile-Water Cluster. Chemistry 2014; 20:2031-9. [DOI: 10.1002/chem.201303321] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 10/02/2013] [Indexed: 01/29/2023]
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13
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Nakamura T, Miyazaki M, Ishiuchi S, Weiler M, Schmies M, Dopfer O, Fujii M. IR Spectroscopy of the 4‐Aminobenzonitrile–Ar Cluster in the S
0
, S
1
Neutral and D
0
Cationic States. Chemphyschem 2012. [DOI: 10.1002/cphc.201200821] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Takashi Nakamura
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226‐8503 (Japan)
| | - Mitsuhiko Miyazaki
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226‐8503 (Japan)
| | - Shun‐ichi Ishiuchi
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226‐8503 (Japan)
| | - Martin Weiler
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226‐8503 (Japan)
| | - Matthias Schmies
- Institut für Optik und Atomare Physik, Technische Universität Berlin, 10623 Berlin (Germany)
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, 10623 Berlin (Germany)
| | - Masaaki Fujii
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226‐8503 (Japan)
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14
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Laser-induced fluorescence and dispersed fluorescence studies of the donor–acceptor system 4-amino 3-methyl benzoic acid methyl ester and its solvated clusters: Evidence of excited-state charge-transfer reaction. J Photochem Photobiol A Chem 2010. [DOI: 10.1016/j.jphotochem.2010.05.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Leyva V, Corral I, Gonzalez L. Ortho-Nitrobenzaldehyde 1:1 Water Complexes. The Influence of Solute Water Interactions in the Vertical Excited Spectrum. Z PHYS CHEM 2009. [DOI: 10.1524/zpch.2008.5387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The intermolecular hydrogen bonding interaction of a water molecule with the caging group ortho-nitrobenzaldehyde (o-NBA) has been studied by means of quantum mechanical methods. The o-NBA chromophore presents two functional groups, NO2 and CHO, interconnected by an intramolecular hydrogen bond. Both groups compete for the interaction with the solvent molecule, leading to eleven possible stable isomers that are very close in energy. The effect of the binding water on the electronic properties of o-NBA has been analyzed in structural terms as well as using the atoms-in-molecules theory of Bader. Binding energies for all complexes are reported, and in general they range from 5 to 13 kJ/mol. Special attention has been paid to the effect of the water molecule on the vertical excitation energies of o-NBA. Upon water complexation the absorption spectrum of o-NBA shifts to higher energies and it is characterized by three bands of comparable intensities as those recently measured for o-NBA in gas phase.
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16
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Osawa K, Hamamoto T, Fujisawa T, Terazima M, Sato H, Kimura Y. Raman Spectroscopic Study on the Solvation of p-Aminobenzonitrile in Supercritical Water and Methanol. J Phys Chem A 2009; 113:3143-54. [DOI: 10.1021/jp8111606] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- K. Osawa
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan, Department of Chemistry, Faculty of Science, Kyoto University, Kyoto 606-8502, Japan, and Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - T. Hamamoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan, Department of Chemistry, Faculty of Science, Kyoto University, Kyoto 606-8502, Japan, and Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - T. Fujisawa
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan, Department of Chemistry, Faculty of Science, Kyoto University, Kyoto 606-8502, Japan, and Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - M. Terazima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan, Department of Chemistry, Faculty of Science, Kyoto University, Kyoto 606-8502, Japan, and Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - H Sato
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan, Department of Chemistry, Faculty of Science, Kyoto University, Kyoto 606-8502, Japan, and Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Y. Kimura
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan, Department of Chemistry, Faculty of Science, Kyoto University, Kyoto 606-8502, Japan, and Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
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17
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Thut M, Tanner C, Steinlin A, Leutwyler S. Time-Dependent Density Functional Theory As a Tool for Isomer Assignments of Hydrogen-Bonded Solute·Solvent Clusters. J Phys Chem A 2008; 112:5566-72. [DOI: 10.1021/jp801044x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Markus Thut
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| | - Christian Tanner
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| | - Andreas Steinlin
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| | - Samuel Leutwyler
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
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18
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Pál K, Kállay M, Köhler G, Zhang H, Bitter I, Kubinyi M, Vidóczy T, Grabner G. Efficient singlet-state deactivation of cyano-substituted indolines in protic solvents via CN--HO hydrogen bonds. Chemphyschem 2008; 8:2627-35. [PMID: 18058777 DOI: 10.1002/cphc.200700479] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The photophysical properties of indoline (I) and three of its derivatives, namely, N-methylindoline (MI), 5-cyanoindoline (CI), and 5-cyano-N-methylindoline (CMI), are studied in H-donating solvents of varying polarity. Based on measurements of fluorescence yield and lifetime, and of triplet yield and hydrated-electron formation, two distinct mechanisms of solvent-induced fluorescence quenching are evidenced. The first mechanism involves the cyano substituent and leads to an increase in the rate constant of internal conversion of one order of magnitude in ethanolic solution and of more than two orders of magnitude in water, as compared to solutions in n-hexane or acetonitrile. A similar trend had previously been observed in the case of 4-N,N-dimethylaminobenzonitrile (DMABN). The second mechanism reduces the fluorescence lifetimes of the non-cyanated derivatives in aqueous solution by one order of magnitude and is related to the formation of hydrated electrons. Neither of these mechanisms is influenced by methylation at the ring nitrogen. Quantum chemical calculations are performed on the ground and excited states of the hydrogen-bonded complexes between protic solvents and MI as well as CMI. Stable hydrogen-bonded configurations involving the CN substituent and a solvent OH group are found; these configurations are stable both in the ground and the first excited singlet states, whereas the corresponding complex at the ring amino nitrogen is stable in the ground state only. The CN--HO configuration is therefore a prime candidate for a mechanistic explanation of the observed quenching by the first mechanism. These findings may have useful applications for the design of fluorescence probes for water in biological systems.
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Affiliation(s)
- Krisztina Pál
- Vidóczy, Institute of Structural Chemistry, Chemical Research Center, Hungarian Academy of Sciences, P.O. Box 17, 1525 Budapest, Hungary
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19
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20
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Affiliation(s)
- Shoichi Yamaguchi
- Molecular Spectroscopy Laboratory, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako 351-0198, Japan
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21
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Ishikawa H, Sugiyama M, Setaka W, Kira M, Mikami N. Direct observation of the solvent reorientation dynamics in the “twisted” intramolecular charge-transfer process of cyanophenyldisilane–water cluster by transient infrared spectroscopy. Phys Chem Chem Phys 2007; 9:117-26. [PMID: 17164893 DOI: 10.1039/b612758d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The solvent reorientation dynamics of the intramolecular charge-transfer (ICT) process of the (p-cyanophenyl)pentamethyldisilane-H(2)O (CPDS-H(2)O) cluster was investigated by transient infrared (IR) absorption spectroscopy. Transient IR bands of two distinct charge-transfer (CT) states appeared in both the OH and the CN-stretching vibration regions. Analyses of the IR spectra and the time profiles of the transient bands revealed that the ICT process of the CPDS-H(2)O cluster proceeds in two steps. The first step is a transition from a photo-prepared locally excited (LE) state to the CT state, which is accompanied by a minor reorientation of the H(2)O moiety. In contrast, the second step is an extensive reorientation process of the H(2)O molecule in the CT state. These two reorientation processes exhibit very distinct pico- and nano-second time scales. In the latter case, a relatively slow time constant of 2 ns was related to a large geometric change in the orientation.
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Affiliation(s)
- Haruki Ishikawa
- Department of Molecular Science and Material Engineering, Graduate School of Science and Technology, Rokko-dai, Nada-ku, Kobe, 657-8501, Japan.
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Matsuda Y, Mori M, Hachiya M, Fujii A, Mikami N. Infrared spectroscopy of size-selected neutral clusters combined with vacuum-ultraviolet-photoionization mass spectrometry. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.02.104] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Alejandro E, Landajo C, Longarte A, Fernández JA, Castaño F. Influence of the aliphatic chain on the (hydrogen-bonded) p-aminobenzonitrile complexes with methanol and ethanol. J Chem Phys 2003. [DOI: 10.1063/1.1615239] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Huang CY, Wang T, Gai F. Temperature dependence of the CN stretching vibration of a nitrile-derivatized phenylalanine in water. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(03)00353-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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