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Salzmann H, McCoy AB, Weber JM. Infrared Spectrum of the Pyrene Anion in the CH Stretching Region. J Phys Chem A 2024; 128:4225-4232. [PMID: 38753443 DOI: 10.1021/acs.jpca.4c00966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
In this work, we report the infrared spectrum of the pyrene anion, measured using messenger tagging with up to three Ar atoms. We assign the spectrum using density functional theory and vibrational perturbation theory. We discuss our results in the context of computed and experimental spectra from the literature as well as recent observations from astronomical sources, addressing the question of whether polycyclic aromatic hydrocarbon anions could contribute to the strong infrared emission bands at 3.29 μm from carbon-rich regions of space.
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Affiliation(s)
- Heinrich Salzmann
- JILA and Department of Chemistry, University of Colorado, Boulder, Colorado 80309-0440, United States
| | - Anne B McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - J Mathias Weber
- JILA and Department of Chemistry, University of Colorado, Boulder, Colorado 80309-0440, United States
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2
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Villani L, Mohire NR, Robertson EG. When Phenyl and Cyclopropyl Rings Meet: Spectroscopic Shifts and Conformational Questions. J Phys Chem A 2023; 127:7557-7567. [PMID: 37650854 DOI: 10.1021/acs.jpca.3c04314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
The electronic and vibrational spectra of cyclopropylbenzene (CPB) and 1,3-bromocyclopropylbenzene (BrCPB) in the gas phase were investigated using quantum chemical calculations in combination with resonance-enhanced multi-photon ionization REMPI techniques including 1c-R2PI, UV-UV holeburning, and IR-UV ion depletion in the CH stretch region. The electronic spectra revealed the presence of a single conformer for both species, with the absence of any perpendicular conformer attributed to low computed barriers to conformer interconversion. Assignment of CPB to the bisected conformer was made through interpreting distinctive CH stretch bands in the IR-UV spectrum in conjunction with quantum chemical calculations. A local anharmonic model based on DFT calculations was adapted to reproduce the cyclopropyl CH stretch spectrum successfully. It was not feasible to definitively assign which bisected conformer of BrCPB was observed using vibrational information alone due to the close similarity of their predicted IR spectra. However, conformational sensitivity of the S1 ← S0 transition dipole moment (TDM) alignments leads to simulated rotational contours that display stark differences, which prompted assignment to the "B1" bisecting conformer with the cyclopropyl ring directed away from the bromine atom. The absence of the energetically comparable "B2" conformer is unexpected. The analysis of the convolution of aromatic and aliphatic modes serves as a basis for assignment in constrained aliphatic systems.
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Affiliation(s)
- Luigi Villani
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Nishit R Mohire
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Evan G Robertson
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
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3
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Foley CD, Allen CD, Au K, Lee C, Rempe SB, Ren P, Sibert EL, Zwier TS. Molecular Cage Reports on Its Contents: Spectroscopic Signatures of Cryo-Cooled K +- and Ba 2+-Benzocryptand Complexes. J Phys Chem A 2023. [PMID: 37478410 DOI: 10.1021/acs.jpca.3c03457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
UV photofragment spectroscopy and IR-UV double resonance methods are used to determine the structure and spectroscopic responses of a three-dimensional [2.2.2]-benzocryptand cage to the incorporation of a single K+ or Ba2+ imbedded inside it (labeled as K+-BzCrypt, Ba2+-BzCrypt). We studied the isolated ion-cryptand complex under cryo-cooled conditions, brought into the gas phase by nano-electrospray ionization. Incorporation of a phenyl ring in place of the central ethyl group in one of the three N-CH2-CH2-O-CH2-CH2-O-CH2-CH2-N chains provides a UV chromophore whose S0-S1 transition we probe. K+-BzCrypt and Ba2+-BzCrypt have their S0-S1 origin transitions at 35,925 and 36,446 cm-1, respectively, blue-shifted by 174 and 695 cm-1 from that of 1,2-dimethoxybenzene. These origins are used to excite a single conformation of each complex selectively and record their IR spectra using IR-UV dip spectroscopy. The alkyl CH stretch region (2800-3000 cm-1) is surprisingly sensitive to the presence and nature of the encapsulated ion. We carried out an exhaustive conformational search of cage conformations for K+-BzCrypt and Ba2+-BzCrypt, identifying two conformations (A and B) that lie below all others in energy. We extend our local mode anharmonic model of the CH stretch region to these strongly bound ion-cage complexes to predict conformation-specific alkyl CH stretch spectra, obtaining quantitative agreement with experiment for conformer A, the gas-phase global minimum. The large electrostatic effect of the charge on the O- and N-lone pairs affects the local mode frequencies of the CH2 groups adjacent to these atoms. The localized CH2 scissors modes are pushed up in frequency by the adjacent O/N-atoms so that their overtones have little effect on the alkyl CH stretch region. However, the localized CH2 wags are nearly degenerate and strongly coupled to one another, producing an array of delocalized wag normal modes, whose highest frequency members reach up above 1400 cm-1. As such, their overtones mix significantly with the CH stretch modes, most notably involving the CH2 symmetric stretch fundamentals of the central ethyl groups in the all-alkyl chains and the CH stretches adjacent to the N-atoms and antiperiplanar to the nitrogen lone pair.
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Affiliation(s)
- Casey D Foley
- Gas Phase Chemical Physics, Sandia National Laboratories, Livermore, California 94550, United States
| | - Cole D Allen
- Department of Biomedical Engineering, University of Texas-Austin, Austin, Texas 78712, United States
| | - Kendrew Au
- Gas Phase Chemical Physics, Sandia National Laboratories, Livermore, California 94550, United States
| | - Chin Lee
- Gas Phase Chemical Physics, Sandia National Laboratories, Livermore, California 94550, United States
| | - Susan B Rempe
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - Pengyu Ren
- Department of Biomedical Engineering, University of Texas-Austin, Austin, Texas 78712, United States
| | - Edwin L Sibert
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Timothy S Zwier
- Gas Phase Chemical Physics, Sandia National Laboratories, Livermore, California 94550, United States
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4
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King KE, Franke PR, Pullen GT, Schaefer HF, Douberly GE. Helium Droplet Infrared Spectroscopy of the Butyl Radicals. J Chem Phys 2022; 157:084311. [DOI: 10.1063/5.0102287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Butyl radicals ( n-, s-, i-,} and tert-butyl) are formed from the pyrolysis of stable precursors (1-pentyl nitrite, 2-methyl-1-butyl nitrite, isopentyl nitrite, and azo- tert-butane, respectively). The radicals are doped into a beam of liquid helium droplets and probed with infrared action spectroscopy from 2700-3125 cm-1, allowing for a low temperature measurement of the CH stretching region. The presence of anharmonic resonance polyads in the 2800-3000 cm-1 region complicates its interpretation. To facilitate spectral assignment, the anharmonic resonances are modeled with two model Hamiltonian approaches that explicitly couple CH stretch fundamentals to HCH bend overtones and combinations: a VPT2+K normal mode model based on CCSD(T) quartic force fields and a semi-empirical local mode model. Both of these computational methods provide generally good agreement with the experimental spectra.
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Affiliation(s)
- Kale E King
- University of Georgia, United States of America
| | | | | | - Henry F. Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, United States of America
| | - Gary E. Douberly
- Department of Chemistry, University of Georgia, United States of America
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5
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Huang Q, Matsuda Y, Eguchi R, Fujii A, Kuo J. Understanding Fermi resonances behind the complex vibrational spectra of the methyl groups in simple alcohol, thiol, and their ethers. J CHIN CHEM SOC-TAIP 2022. [DOI: 10.1002/jccs.202100281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Qian‐Rui Huang
- Institute of Atomic and Molecular Sciences Academia Sinica Taipei Taiwan
| | - Yoshiyuki Matsuda
- Department of Chemistry, Graduate School of Science Tohoku University Sendai Japan
| | - Riku Eguchi
- Department of Chemistry, Graduate School of Science Tohoku University Sendai Japan
| | - Asuka Fujii
- Department of Chemistry, Graduate School of Science Tohoku University Sendai Japan
| | - Jer‐Lai Kuo
- Institute of Atomic and Molecular Sciences Academia Sinica Taipei Taiwan
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6
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Huang QR, Endo T, Mishra S, Zhang B, Chen LW, Fujii A, Jiang L, Patwari GN, Matsuda Y, Kuo JL. Understanding Fermi resonances in the complex vibrational spectra of the methyl groups in methylamines. Phys Chem Chem Phys 2021; 23:3739-3747. [PMID: 33533768 DOI: 10.1039/d0cp05745b] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Vibrational spectra of the methyl groups in mono-methylamine (MMA), dimethylamine (DMA), and trimethylamine (TMA) monomers and their clusters were measured in three experimental set-ups to capture their complex spectral features as a result of bend/umbrella-stretch Fermi resonance (FR). Multiple bands were observed between 2800 and 3000 cm-1 corresponding to the methyl groups for MMA and DMA. On the other hand, the corresponding spectrum of TMA is relatively simple, exhibiting only four prominent bands in the same frequency window, even though TMA has a larger number of methyl groups. The discrete variable representation (DVR) based ab initio anharmonic algorithm with potential energy surface (PES) at CCSD/aug-cc-pVDZ quality is able to capture all the experimentally observed spectral features across all three amines, and the constructed vibrational Hamiltonian was used to analyze the couplings that give rise to the observed FR patterns. It was observed that the vibrational coupling among CH stretch modes on different methyl groups is weak (less than 2 cm-1) and stronger vibrational coupling is found to localize within a methyl group. In MMA and DMA, the complex feature between 2850 and 2950 cm-1 is a consequence of closely packed overtone states that gain intensities by mixing with the stretching modes. The simplification of the spectral pattern of TMA can be understood by the red-shift of the symmetric CH3 stretching modes by about 80 cm-1 relative to MMA, which causes the symmetric CH3 stretch to shift outside the FR window.
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Affiliation(s)
- Qian-Rui Huang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
| | - Tomoya Endo
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aza-Aoba 6-3, Aoba-ku, Sendai 980-8578, Japan.
| | - Saurabh Mishra
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Bingbing Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Collaborative Innovation Center of Chemistry for Energy and Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
| | - Li-Wei Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
| | - Asuka Fujii
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aza-Aoba 6-3, Aoba-ku, Sendai 980-8578, Japan.
| | - Ling Jiang
- State Key Laboratory of Molecular Reaction Dynamics, Collaborative Innovation Center of Chemistry for Energy and Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
| | - G Naresh Patwari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Yoshiyuki Matsuda
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aza-Aoba 6-3, Aoba-ku, Sendai 980-8578, Japan.
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
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7
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Strong Fermi Resonance Associated with Proton Motions Revealed by Vibrational Spectra of Asymmetric Proton‐Bound Dimers. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202012665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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8
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Huang Q, Shishido R, Lin C, Tsai C, Tan JA, Fujii A, Kuo J. Strong Fermi Resonance Associated with Proton Motions Revealed by Vibrational Spectra of Asymmetric Proton‐Bound Dimers. Angew Chem Int Ed Engl 2020; 60:1936-1941. [DOI: 10.1002/anie.202012665] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Qian‐Rui Huang
- Institute of Atomic and Molecular Science Academia Sinica 1 Roosevelt Rd., Sec. 4 Taipei Taiwan
| | - Ryunosuke Shishido
- Department of Chemistry Graduate School of Science Tohoku University Aramaki-Aza-Aoba, Aoba-ku Sendai Japan
| | - Chih‐Kai Lin
- Institute of Atomic and Molecular Science Academia Sinica 1 Roosevelt Rd., Sec. 4 Taipei Taiwan
| | - Chen‐Wei Tsai
- Institute of Atomic and Molecular Science Academia Sinica 1 Roosevelt Rd., Sec. 4 Taipei Taiwan
| | - Jake A. Tan
- Institute of Atomic and Molecular Science Academia Sinica 1 Roosevelt Rd., Sec. 4 Taipei Taiwan
| | - Asuka Fujii
- Department of Chemistry Graduate School of Science Tohoku University Aramaki-Aza-Aoba, Aoba-ku Sendai Japan
| | - Jer‐Lai Kuo
- Institute of Atomic and Molecular Science Academia Sinica 1 Roosevelt Rd., Sec. 4 Taipei Taiwan
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9
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Jiang S, Kong X, Wang C, Zang X, Su M, Zheng H, Zhang B, Li G, Xie H, Yang X, Liu Z, Liu Z, Jiang L. Infrared Spectroscopy of Hydrogen-Bonding Interactions in Neutral Dimethylamine–Methanol Complexes. J Phys Chem A 2019; 123:10109-10115. [DOI: 10.1021/acs.jpca.9b08630] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shukang Jiang
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, 99 Haike Road,
Zhangjiang Hi-Tech Park, Pudong, Shanghai 201210, China
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- School of Physical Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Xiangtao Kong
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Chong Wang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Xiangyu Zang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Mingzhi Su
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Huijun Zheng
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Bingbing Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Gang Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Hua Xie
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Xueming Yang
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, 99 Haike Road,
Zhangjiang Hi-Tech Park, Pudong, Shanghai 201210, China
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- School of Physical Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China
| | - Zhiling Liu
- School of Chemical and Material Science, Key Laboratory of Magnetic Molecules & Magnetic Information Materials, Ministry of Education, Shanxi Normal University, No. 1, Gongyuan Street, Linfen 041004, Shanxi, China
| | - Zhifeng Liu
- Department of Chemistry and Centre for Scientific Modeling and Computation, Chinese University of Hong Kong, Shatin 999077, Hong Kong, China
- CUHK Shenzhen Research Institute, No.10, 2nd Yuexing Road, Nanshan District, Shenzhen 518172, China
| | - Ling Jiang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
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10
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Zhang B, Huang QR, Jiang S, Chen LW, Hsu PJ, Wang C, Hao C, Kong X, Dai D, Yang X, Kuo JL, Jiang L. Infrared spectra of neutral dimethylamine clusters: An infrared-vacuum ultraviolet spectroscopic and anharmonic vibrational calculation study. J Chem Phys 2019; 150:064317. [DOI: 10.1063/1.5086095] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Bingbing Zhang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Qian-Rui Huang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Shukang Jiang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, 99 Haike Road, Shanghai 201210, China
- School of Physical Science and Technology, ShanghaiTech University, 319 Yueyang Road, Shanghai 200031, China
| | - Li-Wei Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Po-Jen Hsu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Chong Wang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Ce Hao
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Xiangtao Kong
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Dongxu Dai
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Ling Jiang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
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11
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Yu Y, Fan W, Wang Y, Zhou X, Sun J, Liu S. Probe of Alcohol Structures in the Gas and Liquid States Using C⁻H Stretching Raman Spectroscopy. SENSORS (BASEL, SWITZERLAND) 2018; 18:E2061. [PMID: 29958405 PMCID: PMC6068699 DOI: 10.3390/s18072061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 06/22/2018] [Accepted: 06/26/2018] [Indexed: 01/16/2023]
Abstract
Vibrational spectroscopy is a powerful tool for probing molecular structures and dynamics since it offers a unique fingerprint that allows molecular identification. One of important aspects of applying vibrational spectroscopy is to develop the probes that can characterize the related properties of molecules such as the conformation and intermolecular interaction. Many examples of vibrational probes have appeared in the literature, including the azide group (⁻N₃), amide group (⁻CONH₂), nitrile groups (⁻CN), hydroxyl group (⁻OH), ⁻CH group and so on. Among these probes, the ⁻CH group is an excellent one since it is ubiquitous in organic and biological molecules and the C⁻H stretching vibrational spectrum is extraordinarily sensitive to the local molecular environment. However, one challenge encountered in the application of C⁻H probes arises from the difficulty in the accurate assignment due to spectral congestion in the C⁻H stretching region. In this paper, recent advances in the complete assignment of C⁻H stretching spectra of aliphatic alcohols and the utility of C⁻H vibration as a probe of the conformation and weak intermolecular interaction are outlined. These results fully demonstrated the potential of the ⁻CH chemical group as a molecular probe.
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Affiliation(s)
- Yuanqin Yu
- Department of Physics, Anhui University, Hefei 230601, China.
| | - Wei Fan
- Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China.
| | - Yuxi Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China.
| | - Xiaoguo Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China.
| | - Jin Sun
- Department of Physics, Anhui University, Hefei 230601, China.
| | - Shilin Liu
- Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China.
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12
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Robertson PA, Villani L, Dissanayake ULM, Duncan LF, Abbott BM, Wilson DJD, Robertson EG. Halocarbons as hydrogen bond acceptors: a spectroscopic study of haloethylbenzenes (PhCH 2CH 2X, X = F, Cl, Br) and their hydrate clusters. Phys Chem Chem Phys 2018. [PMID: 29528053 DOI: 10.1039/c7cp07365h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The electronic spectra of 2-bromoethylbenzene and its chloro and fluoro analogues have been recorded by resonant two-photon ionisation (R2PI) spectroscopy. Anti and gauche conformers have been assigned by rotational band contour analysis and IR-UV ion depletion spectroscopy in the CH region. Hydrate clusters of the anti conformers have also been observed, allowing the role of halocarbons as hydrogen bond acceptors to be examined in this context. The donor OH stretch of water bound to chlorine is red-shifted by 36 cm-1, or 39 cm-1 in the case of bromine. Although classed as weak H-bond acceptors, halocarbons are favourable acceptor sites compared to π systems. Fluorine stands out as the weakest H-bond acceptor amongst the halogens. Chlorine and bromine are also weak H-bond acceptors, but allow for more geometric lability, facilitating complimentary secondary interactions within the host molecule. Ab initio and DFT quantum chemical calculations, both harmonic and anharmonic, aid the structural assignments and analysis.
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Affiliation(s)
- Patrick A Robertson
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, Australia.
| | - Luigi Villani
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, Australia.
| | - Uresha L M Dissanayake
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, Australia.
| | - Luke F Duncan
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, Australia.
| | - Belinda M Abbott
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, Australia.
| | - David J D Wilson
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, Australia.
| | - Evan G Robertson
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, Australia.
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13
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Huang QR, Li YC, Ho KL, Kuo JL. Vibrational spectra of small methylamine clusters accessed by an ab initio anharmonic approach. Phys Chem Chem Phys 2018; 20:7653-7660. [DOI: 10.1039/c8cp00533h] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Anharmonic vibrational calculations on Methylamine (MMA) clusters suggest that the origin of the complexity between 2800 and 3000 cm–1 is caused by Fermi resonance (FR) between the stretching and bending overtones of the CH3 group. In trimer and tetramer, FR also causes complex spectra pattern in the NH2 group.
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Affiliation(s)
- Qian-Rui Huang
- Institute of Atomic and Molecular Sciences
- Taipei 10617
- Taiwan
| | - Ying-Cheng Li
- Institute of Atomic and Molecular Sciences
- Taipei 10617
- Taiwan
| | - Kun-Lin Ho
- Institute of Atomic and Molecular Sciences
- Taipei 10617
- Taiwan
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences
- Taipei 10617
- Taiwan
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14
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Huang QR, Nishigori T, Katada M, Fujii A, Kuo JL. Fermi resonance in solvated H3O+: a counter-intuitive trend confirmed via a joint experimental and theoretical investigation. Phys Chem Chem Phys 2018; 20:13836-13844. [DOI: 10.1039/c8cp02151a] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In this work, we combine both experimental and theoretical approaches to jointly investigate Ne-tagged and Ar-tagged H3O+ (with n = 1, 2, and 3) to gain a better understanding of the Fermi resonance in solvated H3O+.
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Affiliation(s)
- Qian-Rui Huang
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Tomoki Nishigori
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Marusu Katada
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Asuka Fujii
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
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15
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Franke PR, Douberly GE. Rotamers of Isoprene: Infrared Spectroscopy in Helium Droplets and Ab Initio Thermochemistry. J Phys Chem A 2017; 122:148-158. [DOI: 10.1021/acs.jpca.7b10260] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter R. Franke
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, United States
| | - Gary E. Douberly
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, United States
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16
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Hewett DM, Tabor DP, Fischer JL, Sibert EL, Zwier TS. Infrared-Enhanced Fluorescence-Gain Spectroscopy: Conformation-Specific Excited-State Infrared Spectra of Alkylbenzenes. J Phys Chem Lett 2017; 8:5296-5300. [PMID: 28994601 DOI: 10.1021/acs.jpclett.7b02276] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
An ultraviolet-infrared (UV-IR) double-resonance method for recording conformation-specific excited-state infrared spectra is described. The method takes advantage of an increase in fluorescence signal in phenylalkanes produced by infrared excitation of the S1 origin levels of different conformational isomers. The shorter lifetimes of these IR-excited molecules, combined with their red-shifted emission, provides a way to discriminate the fluorescence due to the infrared-excited molecules from the S1 origin fluorescence, resulting in spectra with high signal-to-noise ratios. Spectra for a series of phenylalkanes and a capped phenylalanine derivative (Ac-Phe-NHMe) demonstrate the potential of the method. The excited-state spectrum in the alkyl CH stretch region of ethylbenzene is well-fit by an anharmonic model developed for the ground electronic state, which explicitly takes into account stretch-bend Fermi resonance.
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Affiliation(s)
- Daniel M Hewett
- Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States
| | - Daniel P Tabor
- Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States
| | - Joshua L Fischer
- Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States
| | - Edwin L Sibert
- Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Timothy S Zwier
- Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States
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17
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Basire M, Mouhat F, Fraux G, Bordage A, Hazemann JL, Louvel M, Spezia R, Bonella S, Vuilleumier R. Fermi resonance in CO2: Mode assignment and quantum nuclear effects from first principles molecular dynamics. J Chem Phys 2017; 146:134102. [DOI: 10.1063/1.4979199] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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18
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Franke PR, Tabor DP, Moradi CP, Douberly GE, Agarwal J, Schaefer HF, Sibert EL. Infrared laser spectroscopy of the n-propyl and i-propyl radicals: Stretch-bend Fermi coupling in the alkyl CH stretch region. J Chem Phys 2016; 145:224304. [DOI: 10.1063/1.4971239] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Peter R. Franke
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Daniel P. Tabor
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | | | - Gary E. Douberly
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Jay Agarwal
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Edwin L. Sibert
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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19
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Korn JA, Tabor DP, Sibert EL, Zwier TS. Conformation-specific spectroscopy of alkyl benzyl radicals: Effects of a radical center on the CH stretch infrared spectrum of an alkyl chain. J Chem Phys 2016; 145:124314. [DOI: 10.1063/1.4963227] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Joseph A. Korn
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Daniel P. Tabor
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison, Wisconsin 53706, USA
| | - Edwin L. Sibert
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison, Wisconsin 53706, USA
| | - Timothy S. Zwier
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
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20
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Tabor DP, Hewett DM, Bocklitz S, Korn JA, Tomaine AJ, Ghosh AK, Zwier TS, Sibert EL. Anharmonic modeling of the conformation-specific IR spectra of ethyl, n-propyl, and n-butylbenzene. J Chem Phys 2016; 144:224310. [PMID: 27306010 DOI: 10.1063/1.4953181] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Daniel P. Tabor
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Daniel M. Hewett
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Sebastian Bocklitz
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Joseph A. Korn
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Anthony J. Tomaine
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Arun K. Ghosh
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Timothy S. Zwier
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Edwin L. Sibert
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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21
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Ho KL, Lee LY, Katada M, Fujii A, Kuo JL. An ab initio anharmonic approach to study vibrational spectra of small ammonia clusters. Phys Chem Chem Phys 2016; 18:30498-30506. [DOI: 10.1039/c6cp05537k] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fermi resonance between the N–H stretching (ν1 and ν3) and the overtone of N–H bending (2ν4) in ammonia has hindered the interpretation and assignments of experimental spectra of small ammonia clusters.
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Affiliation(s)
- Kun-Lin Ho
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
- Department of Physics
| | - Lo-Yun Lee
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Marusu Katada
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Asuka Fujii
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
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22
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Yu Y, Wang Y, Hu N, Lin K, Zhou X, Liu S. Cβ–H stretching vibration as a new probe for conformation of n-propanol in gaseous and liquid states. Phys Chem Chem Phys 2016; 18:10563-72. [DOI: 10.1039/c6cp00244g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The CH2 symmetric stretching mode at the β-carbon position can be used as a new probe for the five conformations of n-propanol.
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Affiliation(s)
- Yuanqin Yu
- School of Physics and Material Science
- Anhui University
- Hefei
- China
| | - Yuxi Wang
- Hefei National Laboratory for Physical Sciences at the Microscale
- iChEM (Collaborative Innovation Center of Chemistry for Energy Materials)
- Department of Chemical Physics
- University of Science and Technology of China
- Hefei 230026
| | - Naiyin Hu
- Hefei National Laboratory for Physical Sciences at the Microscale
- iChEM (Collaborative Innovation Center of Chemistry for Energy Materials)
- Department of Chemical Physics
- University of Science and Technology of China
- Hefei 230026
| | - Ke Lin
- Hefei National Laboratory for Physical Sciences at the Microscale
- iChEM (Collaborative Innovation Center of Chemistry for Energy Materials)
- Department of Chemical Physics
- University of Science and Technology of China
- Hefei 230026
| | - Xiaoguo Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale
- iChEM (Collaborative Innovation Center of Chemistry for Energy Materials)
- Department of Chemical Physics
- University of Science and Technology of China
- Hefei 230026
| | - Shilin Liu
- Hefei National Laboratory for Physical Sciences at the Microscale
- iChEM (Collaborative Innovation Center of Chemistry for Energy Materials)
- Department of Chemical Physics
- University of Science and Technology of China
- Hefei 230026
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23
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Sibert EL, Tabor DP, Lisy JM. Modeling the CH Stretch Vibrational Spectroscopy of M+[Cyclohexane] (M = Li, Na, and K) Ions. J Phys Chem A 2015; 119:10293-9. [DOI: 10.1021/acs.jpca.5b07461] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Edwin L. Sibert
- Department
of Chemistry and Theoretical Chemistry Institute, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Daniel P. Tabor
- Department
of Chemistry and Theoretical Chemistry Institute, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - James M. Lisy
- Department
of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
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24
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Tabor DP, Kusaka R, Walsh PS, Sibert EL, Zwier TS. Isomer-Specific Spectroscopy of Benzene-(H2O)n, n = 6,7: Benzene's Role in Reshaping Water's Three-Dimensional Networks. J Phys Chem Lett 2015; 6:1989-1995. [PMID: 26263279 DOI: 10.1021/acs.jpclett.5b00786] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The water hexamer and heptamer are the smallest sized water clusters that support three-dimensional hydrogen-bonded networks, with several competing structures that could be altered by interactions with a solute. Using infrared-ultraviolet double resonance spectroscopy, we record isomer-specific OH stretch infrared spectra of gas-phase benzene-(H2O)(6,7) clusters that demonstrate benzene's surprising role in reshaping (H2O)(6,7). The single observed isomer of benzene-(H2O)6 incorporates an inverted book structure rather than the cage or prism. The main conformer of benzene-(H2O)7 is an inserted-cubic structure in which benzene replaces one water molecule in the S4-symmetry cube of the water octamer, inserting itself into the water cluster by engaging as a π H-bond acceptor with one water and via C-H···O donor interactions with two others. The corresponding D(2d)-symmetry inserted-cube structure is not observed, consistent with the calculated energetic preference for the S4 over the D(2d) inserted cube. A reduced-dimension model that incorporates stretch-bend Fermi resonance accounts for the spectra in detail and sheds light on the hydrogen-bonding networks themselves and on the perturbations imposed on them by benzene.
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Affiliation(s)
- Daniel P Tabor
- †Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Ryoji Kusaka
- ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
- §Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, 739-8526, Japan
| | - Patrick S Walsh
- ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Edwin L Sibert
- †Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Timothy S Zwier
- ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
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25
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Sibert EL, Tabor DP, Kidwell NM, Dean JC, Zwier TS. Fermi Resonance Effects in the Vibrational Spectroscopy of Methyl and Methoxy Groups. J Phys Chem A 2014; 118:11272-81. [DOI: 10.1021/jp510142g] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Edwin L. Sibert
- Department
of Chemistry and Theoretical Chemistry Institute, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Daniel P. Tabor
- Department
of Chemistry and Theoretical Chemistry Institute, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Nathanael M. Kidwell
- Department
of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Jacob C. Dean
- Department
of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Timothy S. Zwier
- Department
of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
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26
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Schleeger M, Nagata Y, Bonn M. Quantifying Surfactant Alkyl Chain Orientation and Conformational Order from Sum Frequency Generation Spectra of CH Modes at the Surfactant-Water Interface. J Phys Chem Lett 2014; 5:3737-3741. [PMID: 26278743 DOI: 10.1021/jz5019724] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We combine second-order nonlinear vibrational spectroscopy and quantum-chemical calculations to quantify the molecular tilt angle and the structural variation of a decanoic acid surfactant monolayer on water. We demonstrate that there is a remarkable degree of delocalization of the vibrational modes along the backbone of the amphiphilic molecule. A simulation-based on modeled sum frequency generation (SFG) spectra offers quantitative insights into the disorder of surfactant monolayers at the water-air interface. It is shown that an average of one gauche defect in the alkyl chain suffices to give rise to the methylene stretch intensity similar in magnitude to the methyl stretch.
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Affiliation(s)
- Michael Schleeger
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Yuki Nagata
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Mischa Bonn
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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