Tracking Intramolecular Vibrational Redistribution ... - ACS Publications

Subscriber access provided by CORNELL UNIVERSITY LIBRARY

Article

Tracking Intramolecular Vibrational Redistribution in Polyatomic Small Molecule Liquids by Ultrafast Time-Frequency-Resolved CARS Xiaosong Liu, Wei Zhang, Yunfei Song, Guoyang Yu, Zhaoyang Zheng, Yangyang Zeng, Zhe Lv, Huajie Song, and Yanqiang Yang J. Phys. Chem. A, Just Accepted Manuscript • DOI: 10.1021/acs.jpca.7b05578 • Publication Date (Web): 13 Jun 2017 Downloaded from http://pubs.acs.org on June 16, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

The Journal of Physical Chemistry A is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

Tracking Intramolecular Vibrational Redistribution in Polyatomic Small Molecule Liquids by Ultrafast Time-Frequency-Resolved CARS Xiaosong Liu†, Wei Zhang†, Yunfei Song‡,Guoyang Yu‡, Zhaoyang Zheng‡, Yangyang Zeng‡, Zhe Lv†, Huajie Song¡, Yanqiang Yang†‡* †

Department of Physics, Harbin Institute of Technology, Harbin, China

¡

Beijing Institute of Applied Physics and Computational Mathematics, Beijing, China

‡

National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics,

China Academy of Engineering Physics, Mianyang, China

KEYWORDS.CARS, selective excitation, IVR, vibrational coupling, molecular symmetry.

ACS Paragon Plus Environment 1


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 15

ABSTRACT. Selective excitation of C–H stretching vibrational modes, detection of intramolecular vibrational energy redistribution (IVR) and vibrational modes coupling in the electronic ground state of benzene are performed by using femtosecond time- and frequency-resolved coherent anti-Stokes Raman Scattering (CARS) spectroscopy. Both of the parent modes in the Raman active bands are coherently excited by ultrafast stimulated Raman pump, giving the initial excitation of 3056cm-1 (A1g) and 3074cm-1 (E2g) and the subsequent intramolecular vibrational energy redistribution from the parent modes to daughter modes of 1181cm-1 and 992cm-1, the coherent vibrational coupling of the relevant modes, are tracked. The directionality and selectivity of IVR and coherent coupling among all the relevant vibrational modes are discussed in the view of molecular symmetry.


Page 3 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1. Introduction Intramolecular vibrational energy redistribution (IVR) is the first step in the energy dissipation of molecules after vibrational excitation1-5. As an elementary process in photochemistry, photobiology and photophysics, IVR has been studied theoretically and experimentally for many years5-8. For complicated biological molecular systems, the vibrational redistribution of isolated molecules has received much attention. The famous Rice-Ramsperger-Kassel-Marcus (RRKM) theory9-10 is useful in treating unimolecular reactions of isolated molecules and clusters. This theory assumes that the initial energy of excitation is redistributed across the whole molecule. For a large molecule, energy levels space are close enough to act as its own heat bath, therefore this theoretical model is applicable to intramolecular vibrational energy transfers to or from the heat bath of the molecule. Although the RRKM theory often provides a good description of IVR in large molecules, but it is not suitable for small molecules. Since a small molecule has a limited number of distant vibrational levels, an intramolecular heat bath cannot formed. To date several vibrational spectroscopic methods have been performed to track the vibrational energy dissipation. The IR-Raman technique for example has been used to monitor time-dependent excitations of individual vibrational modes11-14. The IR pump pulse is used to selectively excite vibrational modes, while the Raman probe pulse is used to track the thermal population of vibrational excited states by acquiring the anti-Stokes scattering spectrum. The vibrational energy transfer from one vibrational mode to others through the surrounding heat bath is then obtained. In deed, it is the non-equilibrium thermal population of the relevant vibrational modes that is detected by the spontaneous anti-Stokes Raman Scattering, rather than the ultrafast coherent intramolecular vibrational energy redistribution in a molecule. In other words, the coherent vibrational energy redistribution cannot be directly detected by this



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 15

technique. The development of double resonance vibrational spectroscopy using IR-UV pump-probe technique, enabled researchers to study vibrational energy dissipation in molecules15-17. One vibrational mode is excited with a picosecond IR laser pulse, and the population in the initially excited vibrational levels and subsequent vibrational energy transfers (VET) are recorded through by multiphoton ionization detection with a picosecond UV pulse. However the vibrational modes involved in the IVR process cannot be distinguished directly. That is, those methods mentioned above can be used to track the relatively slow processes of the thermal population of vibrational states, but not the ultrafast coherent IVR processes. In the multiplex CARS experiment, multiple vibrational modes can be excited and their coupling can be detected as well18-20. In this technique, broadband white-light continuum is used as the Stokes pulse, making it possible to coherently excite multiple vibrational modes and simultaneously detect the coherent coupling among the different modes. Fourier transform (FT) of the time-domain spectrums used to deduce the vibrational modes involved in the coupling that aids the intramolecular vibrational energy redistribution21-23. However the direction of the vibrational energy flow from one mode to another cannot be obtained from the multiplex CARS experiments. In general, selective-and coherent-excitation of vibrational modes and detection of the subsequent IVR process remains a challenging work. In the study reported in this letter, the vibrational mode resolved femtosecond time-resolved CARS is proposed and performed to selectively and coherently excite C–H stretching modes of liquid benzene at 3056cm-1 and 3074cm-1, and to detect the vibrational energy flow from parent modes to low wavenumber vibrations. Time-domain FT analysis is performed to identify the coherent coupling of the relevant vibrational modes. In addition, the details of vibrational mode coupling are examined from the viewpoint of molecular symmetry.


Page 5 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


2. Experiment A pump pulse and a Stokes pulse were incident into the sample to coherently excite vibrational modes. Then the vibrational modes can be detected by the probe pulse. The central wavelength of pump and Stokes pulse were chosen as 640 nm and 800 nm respectively in order to excite C–H stretch vibrational modes of benzene. The probe pulse has the same central wavelength with the pump. A Ti:sapphire laser system (Spectra-Physics) generates a laser beam centered at 800 nm (110 fs, 0.6 mJ, 1 kHz repetition frequency). The output beam is split by a 9:1 beam splitter. The beam with 90% energy was focused into the OPA and further split into two beams as pump and probe pulse laser. The beam with 10% energy is to serve as Stokes pulse laser. Three laser pulses were focused into the sample and the CARS signal is emitted along the phase matching direction. The signal is collected by an optical fiber, then dispersed in a spectrometer (Bruker Optics 500 IS/SM) and detected by a CCD detector (Andor DU440-BU2). The pure liquid benzene (99% purity) is contained in cuvette and the experiment is carried out at room temperature.

3. Results



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 15

Figure 1. (a) Time-and frequency-resolved fs-CARS spectrum of benzene. The parent modes of 3056cm-1 and 3074cm-1, are selectively excited; and in the outside of the excitation region,

low

wavenumber vibrational modes emerge in the circled region by dotted line, which is due to IVR from parent modes. The white curve is the spontaneous Raman spectrum of benzene. (b) The contour plot for the coherent coupling of C–H stretch vibrational modes. The parent modes of 3056cm-1 and 3074cm-1 are selectively excited, and the vibrational band appears at 3165cm-1 via Fermi resonance with low wavenumber modes. (c) The contour plot for the daughter modes are arising from IVR. The directionality and selectivity of IVR and coherent couplings among daughter modes are discussed from the viewpoint of molecular symmetry.


Page 7 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


The selective excitation of the vibrational modes and subsequent IVR is evident in the fs-CARS spectrum, as shown in Figure 1a. The high wavenumber C–H stretching vibrational modes are selectively and coherently excited by a pair of pump and stokes pulses. Frequency difference between the pump (642nm) and Stokes (800nm) pulses is tuned to be in resonance with Raman active modes of benzene centered on ~3100cm-1. Both the Raman active modes of 3056cm-1 and 3074cm-1 are excited simultaneously because the bandwidth of the Stokes and pump pulses is about several hundred wavenumbers. In the region around ~3100cm-1, there are four C–H stretching vibrational modes of 3056cm-1, 3057cm-1, 3064cm-1, and 3074cm-1. The modes of 3056cm-1 and 3074cm-1 are Raman active and excited directly, the other two modes at 3057cm-1 and 3064cm-1 are Raman inactive and cannot be excited directly. But the quantum beats among the C–H stretching vibrational modes can be seen obviously around 3100cm-1 in the contour plot of Figure 1b, which mean that combination band can be excited secondly by Fermi resonance with the low wavenumber Raman active modes. Besides, there are seventeen vibrational modes (see the supporting information, Figure S1) in the range from 800cm-1 to 1500cm-1, which are located outside of the direct excitation region and cannot be excited directly. However the modes of 855cm-1, 992cm-1 and 1181cm-1 are emerging. Even though the spectral resolution does not suffice to distinguish these low wavenumber modes in the Figure 1c, with the help of Fourier analysis, the characteristic frequencies of these modes involved in the vibrational coupling are extracted. (As shown Figure 2(b) and Table 2)



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 15

Figure 2. (a) FT power spectrum of the C–H stretching modes. The modes at 3056cm-1 and 3074cm-1 are selectively excited, and then coherently couple with the combination band at 3165cm-1. (b) FT result of low wavenumber vibrational modes. Vibrational modes at 992cm-1 and 1181cm-1 are secondly excitation from vibrational energy redistribution, another low wavenumber mode at 855cm-1 appears via strong anharmonic coupling, the coherent peaks among these low wavenumber modes show clearly. As mentioned above, FT of time domain CARS signals is performed to identify the high frequency C-H stretching vibrational modes and the low frequency modes in the outside of selective

excitation

region,

which

cannot

be

distinguished

clearly

by

time-and

frequency-resolved fs-CARS spectrum alone. Figure 2a presents FT power spectrum of the C–H stretching vibrational modes. The peaks of FT power spectrum marked by Q1 correspond to the coherent coupling of the C–H stretching modes and combination band 3165cm-1. The details of coherent coupling of C–H stretching modes and their assignments are listed in Table 1. The


Page 9 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


frequency difference between the identified vibrational modes matches well with the results from the FT spectra. Another low-frequency FT peak at 70cm-1 (marked by P) in Figure 3 represents a polarization beat that arises from the intermolecular interactions, which has been reported and conformed in the Kerr effect experiment by Shohei Kakinuma and co-workers3.

Coherent peak Q1

Frequencies of coupling modes /cm-1

Beat frequency/cm-1

3056 and 3563

108

Table 1. Frequency differences between coherent couplings between Raman active modes (3056cm-1) of C–H vibration and combination band 3165cm-1. Combining the results of the time-domain CARS spectrum and frequency-domain FT spectrum, we confirm that all the C–H stretching modes are excited directly and indirectly. The modes of 3056cm-1 and 3074cm-1 are excited directly due to their Raman activities. The 3165cm-1 is combination band and its intensity appears through Fermi resonance with low Raman active modes 992cm-1 and 1181cm-1. This is confirmed by the quantum coherence of the four parent modes in the CARS contour plot and FT power spectrum. Another FT power spectrum of low wavenumber vibrational modes which are secondly excited by IVR is shown in Figure 2(b). It is difficult to distinguish all the modes in the time- and frequency CARS spectrum due to the low spectral resolution, and same as above Fourier analysis was adopted to identify the low wavenumber vibrational modes in the time-and frequency-resolved spectrum. The coherent peaks in the FT spectra indicate beat frequencies among these low wavenumber vibrations. For example, the primary peak at 131cm-1 in the FT power spectrum corresponds to difference frequency between vibrational modes of 855cm-1 and 992cm-1. The second peak at 195cm-1 corresponds to difference frequency between vibrational



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 15

modes 1181 cm-1 and 992cm-1. The details of coupling modes and their frequency-difference are listed in Table 2.

Coherent peak

Frequencies of coupling modes /cm-1

Beat frequency/cm-1

q1

855 and 992

131

q2

1181 and 992

195

Table 2. Frequency differences between the low wavenumber modes of benzene. Beat frequencies arises from the quantum interference among vibrational modes of 992cm-1, 1181cm-1 and 855cm-1. It should be noted that there are there are seventeen modes in the region around 1000cm-1 (for details, see the supporting information, Figure S2), but only three vibrational modes involved in the vibrational coupling. This means that the selectivity occurs in the process of IVR from high frequency C-H vibrational modes to the lower ones. This phenomenon is attributed to the vibrational symmetry. In particular, the symmetry of the low wavenumber modes at 1181cm-1 (E2g) and 992cm-1 (A1g) are the same as those of C–H stretch vibrations at 3056cm-1 (E2g) and 3074cm-1 (A1g), respectively. However, the symmetry of mode at 855cm-1 (E1g) is different from any of the parent modes. Here we attribute the emergence of 855cm-1 mode to its strong anharmonic coupling with the mode of 992cm-1 because its frequency is close to the vibrational modes of 992cm-1. The other fourteen vibrational modes in the low wavenumber region are very weak, therefore they cannot involve in the coherent vibrational coupling. Their vibrational intensities are so weak that cannot be seen in the spontaneous Raman spectrum of benzene, as shown by the white curve in Figure 1(a). Hence it can be confirmed that the vibrational energy flow from the high wavenumber C–H stretching modes to low wavenumber Raman active


Page 11 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


modes, and symmetry of vibrational mode plays an important role in the IVR and vibrational coupling processes.

Figure 3. Selective excitation of Raman active C–H stretching modes and subsequent intramolecular vibrational energy flow to low wavenumber daughter modes. Raman active C–H stretching modes 3074cm-1 and 3056cm-1 are coherent coupled with the Femi resonance modes 3084cm-1and 2950cm-1, respectively. The low wavenumber modes of 992cm-1 and 1181cm-1 are indirectly excited through IVR, and strong coupled with 855cm-1.

4. Discussion The physical picture of selective excitation of high wavenumber parent modes and subsequent IVR in benzene are described in the Figure 3. The selectivity of IVR is related to vibrational symmetry, and vibrational couplings occur more readily among the nearest neighbor modes. The



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 15

Raman active modes of 3056cm-1 and 3074cm-1 are excited directly, and the combination band 3165cm-1 (2×992+1181cm-1) appears through Fermi resonance. In addition, the appearance of low wavenumber modes of 1181cm-1 (C–H bending, symmetry E2g) and 992cm-1 (ring breathing, symmetry A1g) is due to ultrafast IVR, which have the same symmetry with the parent modes at 3056cm-1 (C–H stretching, symmetry E2g) and 3074cm-1 (C-H stretching, symmetry A1g). The symmetry of low wavenumber modes of 855cm-1 (C–H wagging, symmetry E1g) is different from neither of the parent modes, its emergence is due to breakdown of the D6h symmetry during the collision of benzene in liquid or temporal formation of benzene complex.

5. Conclusions In conclusion, the time-and frequency-resolved fs-CARS technique was performed to selectively excite C–H stretching modes and identify the coherent energy flow from high-wavenumber modes to low-wavenumber modes in the process IVR on the electronic ground state. In addition, coherent coupling processes and the selectivity of IVR can be explained reasonably from the viewpoint of molecular symmetry. Our results provide a first glimpse of the immense potential of CARS technique to study ultrafast coherent intramolecular vibrational energy redistribution. This technique is especially attractive as it can be extended to more complex molecules. ASSOCIATED CONTENT Supporting Information. Mode assignment of benzene and beat frequency among low wavenumber modes (PDF) AUTHOR INFORMATION Corresponding Author


Page 13 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


*E-mail: [email protected] Author Contributions The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. Notes The authors declare no competing financial interests. ACKNOWLEDGMENT This work is supported by the National Natural Science Foundation of China (grant numbers 21673211 and 11372053), and the Science Challenging Program (grant number JCKY2016212A501) REFERENCES (1) Andrejeva, A.; Gardner, A. M.; Tuttle, W. D.; Wright, T. G., Consistent Assignment of the Vibrations of Symmetric and Asymmetric Para -Disubstituted Benzene Molecules. Journal of Molecular Spectroscopy 2016, 321, 28-49. (2) Ma, X.; Paul, A. K.; Hase, W. L., Chemical Dynamics Simulations of Benzene Dimer Dissociation. The journal of physical chemistry. A 2015, 119, 6631-40. (3) Kakinuma, S.; Shirota, H., Dynamic Kerr Effect Study on Six-Membered-Ring Molecular Liquids: Benzene, 1,3-Cyclohexadiene, 1,4-Cyclohexadiene, Cyclohexene, and Cyclohexane. The journal of physical chemistry. B 2015, 119, 4713-24. (4) Davies, J. A.; Green, A. M.; Gardner, A. M.; Withers, C. D.; Wright, T. G.; Reid, K. L., Critical Influences on the Rate of Intramolecular Vibrational Redistribution: A Comparative Study of Toluene, Toluene-D3and P-Fluorotoluene. Phys. Chem. Chem. Phys. 2014, 16, 430-443. (5) Atkinson, G. H.; Parmenter, C. S.; Tang, K. Y., Mode‐to‐Mode Vibrational Energy Flow in S1 Benzene. V–V Resonant Energy Transfer, Microscopic Reversibility, and the Role of Level Degeneracies. The Journal of Chemical Physics 1979, 71, 68-72. (6) Miyazaki, M.; Fujii, M., Real Time Observation of the Excimer Formation Dynamics of a Gas Phase Benzene Dimer by Picosecond Pump-Probe Spectroscopy. Physical chemistry chemical physics : PCCP 2015, 17, 25989-97. (7) Namboodiri, M.; Kazemi, M. M.; Zeb Khan, T.; Materny, A.; Kiefer, J., Ultrafast Vibrational Dynamics and Energy Transfer in Imidazolium Ionic Liquids. Journal of the American



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 15

Chemical Society 2014, 136, 6136-41. (8) Midgley, J.; Davies, J. A.; Reid, K. L., Complex and Sustained Quantum Beating Patterns in a Classic Ivr System: The 3(1)5(1) Level in S1 P-Difluorobenzene. The journal of physical chemistry letters 2014, 5, 2484-7. (9) Lu, D. h.; Hase, W. L., Classical Mechanics of Intramolecular Vibrational Energy Flow in Benzene. V. Effect of Zero‐Point Energy Motion. The Journal of Chemical Physics 1989, 91, 7490-7497. (10) Page, R. H.; Shen, Y. R.; Lee, Y. T., Infrared–Ultraviolet Double Resonance Studies of Benzene Molecules in a Supersonic Beam. The Journal of Chemical Physics 1988, 88, 5362-5376. (11) Iwaki, L. K.; Deàk, J. C.; Rhea, S. T.; Dlott, D. D., Vibrational Energy Redistribution in Liquid Benzene. Chemical Physics Letters 1999, 303, 176-182. (12) Pein, B. C.; Dlott, D. D., Modifying Vibrational Energy Flow in Aromatic Molecules: Effects of Ortho Substitution. The journal of physical chemistry. A 2014, 118, 965-73. (13) Pein, B. C.; Sun, Y.; Dlott, D. D., Unidirectional Vibrational Energy Flow in Nitrobenzene. The journal of physical chemistry. A 2013, 117, 6066-72. (14) Wang, Z.; Pakoulev, A.; Dlott, D. D., Watching Vibrational Energy Transfer in Liquids with Atomic Spatial Resolution. Science 2002, 296, 2201-3. (15) Yamada, Y.; Katsumoto, Y.; Ebata, T., Picosecond Ir-Uv Pump-Probe Spectroscopic Study on the Vibrational Energy Flow in Isolated Molecules and Clusters. Physical chemistry chemical physics : PCCP 2007, 9, 1170-85. (16) Yamada, Y.; Okano, J.-i.; Mikami, N.; Ebata, T., Picosecond Ir-Uv Pump-Probe Spectroscopic Study on the Intramolecular Vibrational Energy Redistribution of Nh[Sub 2] and Ch Stretching Vibrations of Jet-Cooled Aniline. The Journal of Chemical Physics 2005, 123, 124316. (17) Yamada, Y.; Ebata, T.; Kayano, M.; Mikami, N., Picosecond Ir-Uv Pump-Probe Spectroscopic Study of the Dynamics of the Vibrational Relaxation of Jet-Cooled Phenol. I. Intramolecular Vibrational Energy Redistribution of the Oh and Ch Stretching Vibrations of Bare Phenol. J Chem Phys 2004, 120, 7400-9. (18) Kiefer, J.; Namboodiri, M.; Kazemi, M. M.; Materny, A., Time-Resolved Femtosecond Cars of the Ionic Liquid 1-Ethyl-3-Methylimidazolium Ethylsulfate. Journal of Raman Spectroscopy 2015, 46, 722-726. (19) Chen, T.; Vierheilig, A.; Waltner, P.; Kiefer, W.; Materny, A., The Relaxation Process of the Excitonic States in Polydiacetylene Studied by Time- and Wavenumber-Resolved Femtosecond Coherent Anti-Stokes Raman Scattering. Chemical Physics Letters 2000, 325, 176-182. (20) Chen, T.; Vierheilig, A.; Waltner, P.; Heid, M.; Kiefer, W.; Materny, A., Femtosecond Laser-Controlled Selective Excitation of Vibrational Modes on a Multidimensional Ground State Potential Energy Surface. Chemical Physics Letters 2000, 326, 375-382.


Page 15 of 15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


TOC GRAPHIC


Tracking Intramolecular Vibrational Redistribution ... - ACS Publications

Recommend Documents