Intramolecular vibrational dynamics of propyne and its derivatives: The role of vibrational-rotational mixing

Malinovsky, A. L.; Макаров, А. А.; Ryabov, E. A.

doi:10.1134/s1063776108010032

Cited by 13 publications

(16 citation statements)

References 44 publications

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“…The knowledge of this quantity makes it possible to estimate the density of states of the molecule that are efficient with respect to the IVR process. In ref (see also refs and ), a universal function has been calculated, which describes the dependence of σ on the product x = ℏ W ρ, where W is the initial rate of decay from the initial state to the ensemble of states with the density ρ that obey the statistics of the Gaussian orthogonal ensemble (GOE), which is typical for the dynamic chaos range. , From the viewpoint of the model that was considered in the preceding subsection, it is interesting to consider the question about the density ρ A of states bold-scriptA , which are efficient with respect to the first, fast, stage of the IVR process. In terms of eq , the dilution factor that characterizes this stage is estimated as σ ≈ normalΓ normalA → normalI normalΓ normalI → normalA + normalΓ normalA → normalI = 1 normalΓ normalI → normalB ( τ 1 + τ 2 − Γ I → B τ 1 τ 2 ) where expression is used.…”

Section: Discussionmentioning

confidence: 99%

“…A simple phenomenological model that is based on kinetic equations for the populations N I and N A is considered in the Appendix. (The usage of the rate equations is justified with a good accuracy because in our experimental conditions we deal with very large ensembles of initial vibrational–rotational states (see, e.g., results of model calculations based on the Schrödinger equation and presented in refs and ).) In accordance with the notation of Figure , unknown rates of the forward and backward processes bold-scriptI ⇔ bold-scriptA are introduced: Γ I→A and Γ A→I .…”

Section: Discussionmentioning

confidence: 99%

“…In these experiments, an IR pulse of the pump radiation produced a one-quantum excitation of vibrations of the H–C bond (∼3330 cm –1 ). To probe excited vibrational states, the methods of IR absorption − and time-resolved Raman scattering − were used. Characteristic IVR times, τ IVR , measured in these experiments lie in the range from tens of picoseconds to a few nanoseconds.…”

Section: Introductionmentioning

confidence: 99%

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Intramolecular Vibrational Dynamics in Free Polyatomic Molecules with C═O Chromophore Bond Excited by Resonant Femtosecond IR Laser Radiation

et al. 2014

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In nine polyatomic molecules, we have studied the intramolecular redistribution of vibrational energy from chromophore C═O group excited by a resonant femtosecond IR laser radiation at a wavelength of ∼5 μm. All experiments have been performed in the gas phase using the IR-IR pump-probe technique in combination with the spectral analysis of the probe radiation. For molecules with one C═O end group, characteristic times of intramolecular vibrational redistribution (IVR) lie in the range between 2.4 and 20 ps and correlate with the density of four-frequency Fermi resonances. The IVR times in metal carbonyl molecules are anomalously long, being ∼1.0 ns for Fe(CO)5 and ∼1.5 ns for Cr(CO)6. In the CH3(C═O)OC2H5 and H2CCH(C═O)OC2H5 molecules, it has been observed that there are two characteristic IVR times, which differ by an order of magnitude from each other; this was interpreted in terms of the developed model of "accumulating states". For the ICF2COF molecule, it has been revealed that the IVR time decreases with increasing level of the vibrational excitation of the C═O bond of the molecule.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Intramolecular Vibrational Dynamics in Free Polyatomic Molecules with C═O Chromophore Bond Excited by Resonant Femtosecond IR Laser Radiation

et al. 2014

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“…The relation between W, σ, and ρ eff will be clarified in section 2. As a useful example, this relation made it possible to establish that, for some molecules, the IVR spreads on not only all accessible vibrational states (with the possible exclusion of the torsion modes [10]), but, what matters much more for the value of ρ eff , the IVR occurs without conservation of the rotational quantum number K in cases of symmetric-top molecules, or K a in cases of asymmetric tops (see [11][12][13][14][15][16][17] for details).…”

Section: Photon Echoes For Studying Intramolecular Vibrational Redist...mentioning

confidence: 99%

Photon echoes for studying intramolecular vibrational redistribution: on determination of the dilution factors

Макаров¹

2014

Laser Phys.

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A theory of the photon echo is presented for excitation of the vibrational-rotational transitions in a polyatomic molecule followed by the process of intramolecular vibrational redistribution (IVR). A model is considered that includes a description of IVR using the general statistical properties of chaotic states rather than phenomenological. Special attention is paid to the echo signals at the delay times that are considerably larger than the characteristic times of IVR. It is shown that echo measurements for the far plateau of the IVR curve can provide, directly or indirectly, determination of the so-called dilution factors; their values are of primary importance for estimating effective density of the molecular states that participate in IVR. Differences between the echo and anti-Stokes Raman scattering, really used for the same purposes, are discussed.

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“…Due to the high pressure and the slow relaxation process collisional effects could not be excluded in these earlier experiments 57 (see also ref. [60][61][62].…”

Section: Introductionmentioning

confidence: 99%

Intramolecular vibrational energy redistribution in HCCCH₂X (X = Cl, Br, I) measured by femtosecond pump–probe experiments in a hollow waveguide

Kushnarenko

Miloglyadov

Qüack

et al. 2018

Phys. Chem. Chem. Phys.

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From the analysis of high resolution overtone spectra it is well established that intramolecular vibrational energy redistribution (IVR) from an initially excited CH-stretching vibration is strongly influenced by its chemical environment. Due to a pronounced Fermi resonance between the CH-stretching and CH-bending vibrations a vibrational energy redistribution on the subpicosecond time scale (∼100 fs) is found for alkyl (sp3) CH-chromophores, whereas this doorway for energy flow is blocked for the acetylenic (sp) CH-stretching vibration because of the much lower CH-bending frequency. From the analysis of the high resolution spectra lifetimes for the initial CH-vibrational excitation of 10-100 ps or longer have been derived. In the present work we have investigated the IVR process for HCCCH2Br, HCCCH2Cl, and HCCCH2I after excitation of the first overtone of the CH-stretching vibration of the CH2X- and the CCH-group by time resolved femtosecond pump-probe experiments in a hollow waveguide. For HCCCH2Br and HCCCH2Cl a clearly different IVR behavior was found for the two different chemical environments. For the excitation of the alkyl CH-chromophore very fast initial relaxation times were found together with a slower relaxation process with τ2 = 15-40 ps, whereas for the acetylenic CH-stretching vibration a relaxation time τ3 = 70-200 ps has been determined. For HCCCH2I also for the excitation of the CCH-group a relatively fast relaxation process with a time constant τ2 = 6 ps could be identified which might result from a not yet identified strong vibrational coupling between the excited first overtone of the acetylenic CH-stretching vibrations with a combination state including the CI-stretching vibration.

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Intramolecular vibrational dynamics of propyne and its derivatives: The role of vibrational-rotational mixing

Cited by 13 publications

References 44 publications

Intramolecular Vibrational Dynamics in Free Polyatomic Molecules with C═O Chromophore Bond Excited by Resonant Femtosecond IR Laser Radiation

Intramolecular Vibrational Dynamics in Free Polyatomic Molecules with C═O Chromophore Bond Excited by Resonant Femtosecond IR Laser Radiation

Photon echoes for studying intramolecular vibrational redistribution: on determination of the dilution factors

Intramolecular vibrational energy redistribution in HCCCH₂X (X = Cl, Br, I) measured by femtosecond pump–probe experiments in a hollow waveguide

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Intramolecular vibrational dynamics of propyne and its derivatives: The role of vibrational-rotational mixing

Cited by 13 publications

References 44 publications

Intramolecular Vibrational Dynamics in Free Polyatomic Molecules with C═O Chromophore Bond Excited by Resonant Femtosecond IR Laser Radiation

Intramolecular Vibrational Dynamics in Free Polyatomic Molecules with C═O Chromophore Bond Excited by Resonant Femtosecond IR Laser Radiation

Photon echoes for studying intramolecular vibrational redistribution: on determination of the dilution factors

Intramolecular vibrational energy redistribution in HCCCH2X (X = Cl, Br, I) measured by femtosecond pump–probe experiments in a hollow waveguide

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Product

Resources

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Intramolecular vibrational energy redistribution in HCCCH₂X (X = Cl, Br, I) measured by femtosecond pump–probe experiments in a hollow waveguide