IR and Raman study of rotational relaxation of furan and thiophene. I. Bandwidths. Comparison of the rotations about the principal axes of inertia

Pinan-Lucarré, Jean-Paul; Loisel, J.; Vincent‐Geisse, J.

doi:10.1016/0301-0104(81)85122-1

Cited by 10 publications

(3 citation statements)

References 15 publications

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“…There are at least three reasons why one might observe broader bands in the Raman: one addressing homogeneous broadening and two addressing inhomogenous broadening. When considering homogeneous broadening, the contribution to the vibrational linewidth arising from rotational dephasing is greater for Raman bands than for IR bands − (up to a factor of 3) . Given that the rotational lifetime of the carbonyl groups is very short (the rate of exchange is fast), we might expect significant contributions to the total width from rotational dephasing, resulting in measurable differences in the bandwidth of the carbonyl peaks in IR and Raman spectra.…”

Section: Resultsmentioning

confidence: 99%

“…However, as IR and Raman spectra result from different phenomena and employ different mechanisms by which the vibrational data is collected, these differences could result in dynamic IR and Raman providing different results. For instance, bands in IR and Raman spectra, which arise from identical normal modes, can have different homogeneous and inhomogenous bandwidths. ,− This idea is addressed more thoroughly in the discussion section, but is critical, as the determination of rate constants in dynamic IR and Raman is based upon analysis of these bandwidths. Furthermore, the use of a focused laser beam in Raman microscopy could result in increases in local temperature, which would give rise to increased rates of exchange.…”

Section: Introductionmentioning

confidence: 99%

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Direct Test of the Equivalency of Dynamic IR and Dynamic Raman Spectroscopies As Techniques for Observing Ultrafast Molecular Dynamics

et al. 2013

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We report the temperature-dependent infrared (IR) and Raman spectra of Fe(CO)3(η(4)-norbornadiene). This molecule undergoes carbonyl ligand site exchange on the vibrational time scale, and the effect of this exchange is observable as coalescence of the carbonyl bands in both the IR and Raman spectra. We outline a theory that we used to account for these effects and report simulations of the experimental spectra. We used these simulations to extract the carbonyl ligand exchange rates at various temperatures from the IR and Raman data. This data was used to calculate the activation energy for carbonyl exchange, yielding activation energies of 1.2 ± 0.2 and 1.4 ± 0.1 kcal/mol from the IR and Raman data, respectively. These activation energies are statistically identical and are consistent with previously reported values. This constitutes the first direct comparison between dynamic IR and Raman spectroscopies, and we find them to give identical results.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Direct Test of the Equivalency of Dynamic IR and Dynamic Raman Spectroscopies As Techniques for Observing Ultrafast Molecular Dynamics

et al. 2013

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“…Microwave data and low-resolution IR data of both molecules have been published [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Those earlier papers reported the rotational and centrifugal constants of the ground state, the molecular structure, and gave a vibrational analysis of band origins and the force field.…”

Section: Introductionmentioning

confidence: 99%

High Resolution IR-Spectra of Furane and Thiophene

Pankoke

Yamada

Winnewisser

1993

Zeitschrift Für Naturforschung A

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University of Gießen. An interactive Loomis-Wood program was applied to identify the c-type transitions of furane and thiophene. The molecular parameters were determined from the observed line positions and the available microwave data by least-squares-fits using Watson's ^-reduced Hamiltonian. Some relations among parameters appearing in different formulations of the Hamiltonian are represented explicitly in connection with the derivation of the unreduced constants. The unreduced constants were derived for both molecules using the planarity relations. We determined the inertial defects to be « 0.05 amuÄ 2 in the ground state and « -0.2 amuÄ 2 in the excited state for both furane and thiophene.

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