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Fujiyoshi S, Ishibashi TA, Onishi H. Molecular Vibrations at a Liquid−Liquid Interface Observed by Fourth-Order Raman Spectroscopy. J Phys Chem B 2006; 110:9571-8. [PMID: 16686504 DOI: 10.1021/jp060457g] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Interface-selective, Raman-based observation of molecular vibrations is demonstrated at a liquid-liquid interface. An aqueous solution of oxazine 170 dye interfaced with hexadecane is irradiated with pump and probe light pulses of 630-nm wavelengths in 17-fs width. The ultrashort pulses are broadened due to group velocity dispersion when traveling through the hexadecane layer. The dispersion is optically corrected to give an optimized instrumental response. The pump pulse induces a vibrational coherence of the dye via impulsive stimulated Raman scattering. The probe pulse generates second-harmonic light at the interface. The efficiency of the generation is modulated as a function of the pump-probe delay by the coherently excited molecules. Fourier transformation of the modulated efficiency presents the frequency spectrum of the vibrations. Five bands are recognized at 534, 557, 593, 619, and 683 cm(-1). The pump-and-probe process induces a fourth-order optical response that is forbidden in a centrosymmetric media. The contribution of an undesired, cascaded optical process is quantitatively considered and excluded.
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Affiliation(s)
- Satoru Fujiyoshi
- Department of Chemistry, Faculty of Science, Kobe University, Nada, Kobe 657-8501, Japan.
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Fujiyoshi S, Ishibashi TA, Onishi H. Fourth-Order Raman Spectroscopy of Wide-Band Gap Materials. J Phys Chem B 2005; 109:8557-61. [PMID: 16852009 DOI: 10.1021/jp051203i] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Low-frequency surface vibrations were observed on a rutile TiO(2)(110) surface covered with trimethyl acetate (TMA) by using fourth-order Raman spectroscopy. The TMA-covered surface interfaced to air was irradiated with 18-fs light at a wavelength of 630 nm. A pump pulse excited vibrational coherence of Raman-active modes and a probe pulse interacts with the coherently excited surface to generate second harmonic light (315 nm), the intensity of which oscillated as a function of the pump-probe delay. Four bands were recognized at 180, 357, 444, and 826 cm(-1) in the Fourier transformation spectrum of the oscillation and assigned to bulk phonons modified by the presence of the surface boundary condition. The Raman transition for the pump was nonresonant to the band gap excitation of TiO(2), as evidenced by the oscillation phase relative to the pump irradiation and by the oscillation amplitude as a function of the pump power. The observable range of this surface-selective spectroscopy is extended to wide-band gap materials on which one-photon resonance enhancement of the Raman-pump efficiency cannot be expected.
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Affiliation(s)
- Satoru Fujiyoshi
- Department of Chemistry, Faculty of Science, Kobe University, Nada, Kobe, 657-8501 Japan.
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Fujiyoshi S, Ishibashi TA, Onishi H. Fifth-Order Raman Spectroscopy of Excited-State Molecules. J Phys Chem A 2004. [DOI: 10.1021/jp0461899] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Satoru Fujiyoshi
- Surface Chemistry Laboratory, Kanagawa Academy of Science and Technology (KAST), KSP, Sakado, Takatsu, Kawasaki, 213-0012, Japan, Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Honmachi, Kawaguchi, 332-0012, Japan, Department of Chemistry, Faculty of Science, Kobe University, Nada, Kobe, 657-8501, Japan, and Department of Chemistry, Graduate School of Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Taka-aki Ishibashi
- Surface Chemistry Laboratory, Kanagawa Academy of Science and Technology (KAST), KSP, Sakado, Takatsu, Kawasaki, 213-0012, Japan, Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Honmachi, Kawaguchi, 332-0012, Japan, Department of Chemistry, Faculty of Science, Kobe University, Nada, Kobe, 657-8501, Japan, and Department of Chemistry, Graduate School of Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Hiroshi Onishi
- Surface Chemistry Laboratory, Kanagawa Academy of Science and Technology (KAST), KSP, Sakado, Takatsu, Kawasaki, 213-0012, Japan, Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Honmachi, Kawaguchi, 332-0012, Japan, Department of Chemistry, Faculty of Science, Kobe University, Nada, Kobe, 657-8501, Japan, and Department of Chemistry, Graduate School of Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan
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Fujiyoshi S, Ishibashi TA, Onishi H. Interface-Specific Vibrational Spectroscopy of Molecules with Visible Lights. J Phys Chem B 2004. [DOI: 10.1021/jp047877v] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Satoru Fujiyoshi
- Surface Chemistry Laboratory, Kanagawa Academy of Science and Technology (KAST), KSP East 308, 3-2-1 Sakado, Takatsu, Kawasaki, 213-0012, Japan, and Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, 4-1-8 Honmachi, Kawaguchi, 332-0012, Japan
| | - Taka-aki Ishibashi
- Surface Chemistry Laboratory, Kanagawa Academy of Science and Technology (KAST), KSP East 308, 3-2-1 Sakado, Takatsu, Kawasaki, 213-0012, Japan, and Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, 4-1-8 Honmachi, Kawaguchi, 332-0012, Japan
| | - Hiroshi Onishi
- Surface Chemistry Laboratory, Kanagawa Academy of Science and Technology (KAST), KSP East 308, 3-2-1 Sakado, Takatsu, Kawasaki, 213-0012, Japan, and Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, 4-1-8 Honmachi, Kawaguchi, 332-0012, Japan
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