Spectra and Dynamics of Coupled Vibrations in Polyatomic Molecules

Qüack, Martin

doi:10.1146/annurev.pc.41.100190.004203

Cited by 462 publications

(292 citation statements)

References 82 publications

(116 reference statements)

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“…One observes two moderately well separated bands. Integrating the spectrum from 38632"0cm -1 to 38635"8cm -1 and from 38635-8cm -1 to 38639.2cm -1, respectively, one finds the ratio Ghigh :Glo w = 1"2-t-0"1 for the relative integrated band strengths of high-frequency band and low-frequency band in agreement with the value 1.3 given by Rosman and Rice [33], with G = fa(u)v -1 dv oc 1#~ [2, see [51]. Using the automatic assignment procedure [39], we were able to assign all the rovibronic lines.…”

Section: Analysis Of the Spectrumsupporting

confidence: 82%

Sub-Doppler supersonic jet spectra of the coupled 6a¹₀and 6b¹₀vibronic bands of the S₁(¹B_2u) ← S₀(¹A_1g) transition in monodeuterobenzene and their rovibrational analysis

et al. 1994

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We report the rotationally resolved spectra of C6HsD obtained in a supersonic seeded jet by Doppler free UV laser spectroscop~ with an effective resolution of about ff0045 cm -1. The coupled 6a~ and 6b0 vibronic transitions are analysed in terms of their spectroscopic constants (~0 = 38 634.2429 cm -~ for 1 1 1 6a0 and u0 =38637.1792cm-for 6b0) and the Coriolis coupling constant (~ = 0"095 85cm -1, obtained by constraining the C rotational constants to be equal for 6a 1 and 6b 1. Simulations of the spectra result in rotational temperatures of about 2 K. The polarizations of the two transitions could be determined unambiguously as well as the approximate ratio of the transition moments.

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Section: Analysis Of the Spectrumsupporting

confidence: 82%

Sub-Doppler supersonic jet spectra of the coupled 6a¹₀and 6b¹₀vibronic bands of the S₁(¹B_2u) ← S₀(¹A_1g) transition in monodeuterobenzene and their rovibrational analysis

et al. 1994

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“…Despite its significance, very little experimental work has been done to unravel the molecular mechanisms of vibrational energy transport in this regime. The fundamental process behind vibrational energy transport is intramolecular vibrational energy redistribution (IVR), which is typically discussed in terms of energy or state space [5][6][7][8][9], but it also may have a spatial component [10]. Most studies that emphasize the spatial character concentrated on the vibrational energy flow from a heme group in proteins into the surrounding solvent [11][12][13][14][15], which has been attributed to the transport through the propionate side chain [16,17].…”

Section: Introductionmentioning

confidence: 99%

Vibrational energy transport in the presence of intrasite vibrational energy redistribution

Schade

Hamm

2009

The Journal of Chemical Physics

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Vibrational energy transport in the presence of intrasite vibrational energy redistribution AbstractThe mechanism of vibrational energy flow is studied in a regime where a diffusion equation is likely to break down, i.e., on length scales of a few chemical bonds and time scales of a few picoseconds. This situation occurs, for example, during photochemical reactions in protein environment. To that end, a toy model is introduced that on the one hand mimics the vibrational normal mode distribution of proteins, and on the other hand is small enough to numerically time propagate the system fully quantum mechanically. Comparing classical and quantum-mechanical results, the question is addressed to what extent the classical nature of the molecular dynamics simulations (which would be the only choice for the modeling of a real molecular system) affects the vibrational energy flow mechanism. Small differences are found which are due to the different ways classical and quantum mechanics distribute thermal energy over vibrational modes. In either case, a ballistic and a diffusive phase can be identified. For these small length and time scales, the latter is governed by intrasite vibrational energy redistribution, since vibrational energy does not necessarily thermalize completely within individual peptide units. Overall, the model suggests a picture that unifies many of the observations made recently in experiments.Vibrational energy transport in the presence of intra-site vibrational energy redistribution Marco Schade and Peter HammPhysikalisch-Chemisches Institut, Universität Zürich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland (Dated: September 16, 2009) The mechanism of vibrational energy flow is studied in a regime where a diffusion equation is likely to break down, i.e. on length scales of a few chemical bonds and timescales of a few picoseconds. This situation occurs for example during photochemical reactions in protein environment. To that end, a toy model is introduced that on the one hand mimics the vibrational normal mode distribution of proteins, and on the other hand is small enough to numerically time-propagate the system fully quantum-mechanically. Comparing classical and quantum-mechanical results, the question is addressed to what extent the classical nature of the molecular dynamics simulations (which would be the only choice for the modelling of a real molecular system) affects the vibrational energy flow mechanism. Small differences are found which are due to the different ways how classical and quantum mechanics distribute thermal energy over vibrational modes. In either case, a ballistic and a diffusive phase can be identified. For these small length and timescales, the latter is governed by intra-site vibrational energy redistribution, since vibrational energy does not necessarily thermalize completely within individual peptide units. Overall, the model suggests a picture that unifies many of the observations made recently in experiments.

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“…The energy levels are obtained and the overall mechanism may be discussed in term of time-dependent dynamics between bright and dark states. It is noteworthy that such a description belongs to the Bixon and Jortner approach (Bixon & Jortner 1968), while others prefer manipulations of the eigenstates as long as it is possible, which is particularly adapted when ultra-high resolution spectroscopy in the frequency resolved domain provides the complete set of information (Quack 1990). In the case of PAHs, the dominant description is that from Bixon and Jortner.…”

Section: Nonradiative Transitions In Pahs: Present Statusmentioning

confidence: 99%

Electronic Spectroscopy of PAHs

Pino

Carpentier

Féraud

et al. 2011

EAS Publications Series

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Abstract. Polycyclic aromatic hydrocarbons are a class of molecules of broad interest that has long been explored by various spectroscopic techniques. The electronic spectroscopy of these species is of particular interest since it provides a framework for the understanding of the electronic structure of large polyatomic molecules. Such studies also allow the systematic investigation of electronic relaxation mechanisms in large molecules. In this review, we focus on the gas-phase experimental work on such systems and present the latest progress. We also underline the challenges that remain to be tackled. A focus on the understanding of the electronic relaxation pathways at work in gas-phase PAHs will also be presented, as well as their possible manifestation in space.

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Spectra and Dynamics of Coupled Vibrations in Polyatomic Molecules

Cited by 462 publications

References 82 publications

Sub-Doppler supersonic jet spectra of the coupled 6a¹₀and 6b¹₀vibronic bands of the S₁(¹B_2u) ← S₀(¹A_1g) transition in monodeuterobenzene and their rovibrational analysis

Sub-Doppler supersonic jet spectra of the coupled 6a¹₀and 6b¹₀vibronic bands of the S₁(¹B_2u) ← S₀(¹A_1g) transition in monodeuterobenzene and their rovibrational analysis

Vibrational energy transport in the presence of intrasite vibrational energy redistribution

Electronic Spectroscopy of PAHs

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Spectra and Dynamics of Coupled Vibrations in Polyatomic Molecules

Cited by 462 publications

References 82 publications

Sub-Doppler supersonic jet spectra of the coupled 6a10and 6b10vibronic bands of the S1(1B2u) ← S0(1A1g) transition in monodeuterobenzene and their rovibrational analysis

Sub-Doppler supersonic jet spectra of the coupled 6a10and 6b10vibronic bands of the S1(1B2u) ← S0(1A1g) transition in monodeuterobenzene and their rovibrational analysis

Vibrational energy transport in the presence of intrasite vibrational energy redistribution

Electronic Spectroscopy of PAHs

Contact Info

Product

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Sub-Doppler supersonic jet spectra of the coupled 6a¹₀and 6b¹₀vibronic bands of the S₁(¹B_2u) ← S₀(¹A_1g) transition in monodeuterobenzene and their rovibrational analysis

Sub-Doppler supersonic jet spectra of the coupled 6a¹₀and 6b¹₀vibronic bands of the S₁(¹B_2u) ← S₀(¹A_1g) transition in monodeuterobenzene and their rovibrational analysis