Possible model states for the B phase of superfluid<sup>3</sup>He

Moore, M A; Vuorio, Marja; Haavasoja, T.; Vidberg, H J

doi:10.1088/0022-3719/7/23/003

Cited by 8 publications

(8 citation statements)

References 11 publications

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“…Thus, the measured rotational and translational energy distributions suggest that excitation of the high frequency bath vibrational modes is mediated by long range attractive forces. 36,37 Additionally, excitation of the CO 2 3 ͑antisymmetric stretch͒ mode via collisions with highly vibrationally excited pyrazine becomes more efficient as the cell temperature is lowered, which is also consistent with a resonant, long range energy transfer mechanism. 30 Donor relaxation via long range V -V energy transfer to a triatomic bath molecule is quite inefficient compared to the V -RT channel, although this may not be the case for larger bath molecules.…”

Section: Introductionsupporting

confidence: 62%

The collisional deactivation of highly vibrationally excited pyrazine by a bath of carbon dioxide: Excitation of the infrared inactive (100), (020), and (0220) bath vibrational modes

Michaels

Mullin

Park

et al. 1998

The Journal of Chemical Physics

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The collisional quenching of highly vibrationally excited pyrazine, C4H4N2, by CO2 has been investigated using high resolution infrared transient absorption spectroscopy at a series of cell temperatures. Attention is focused on collisions which result in excitation of the Fermi-mixed bath vibrational states (1000) and (0200), along with the unmixed overtone bend state (0220). The vibrationally hot (Evib≈5 eV) pyrazine molecules are formed by 248 nm excimer laser pumping, followed by rapid radiationless decay to the ground electronic state. The nascent rotational and translational product state distributions of the CO2 molecules in each vibrationally excited state are probed at short times following the excitation of pyrazine. The temperature dependence of this process, along with the CO2 product state distributions and velocity recoils, strongly suggest that the vibrational excitation of CO2 is dominated by a long-range electrostatic interaction despite the fact that the dipole transition matrix elements connecting the CO2 ground state to the excited states vanish for the isolated molecule. The vibrational energy transfer is accompanied by very little rotational and translational excitation and displays the characteristic strong, inverse temperature dependence (probability of transfer increases with decreasing temperature) expected of energy transfer mediated by a long range attractive interaction. A number of possible explanations for this apparent anomaly are considered, of which energy transfer mediated by dipole/quadrupole forces appears to be the most consistent with the data.

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Section: Introductionsupporting

confidence: 62%

The collisional deactivation of highly vibrationally excited pyrazine by a bath of carbon dioxide: Excitation of the infrared inactive (100), (020), and (0220) bath vibrational modes

Michaels

Mullin

Park

et al. 1998

The Journal of Chemical Physics

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“…This implies that the corresponding transfer efficiencies are much higher than would be expected for simple thermal equilibration (e.g., by vibration-to-translation/ rotation energy transfer). [1][2][3][4][5][6][7] As will be discussed in Section IV below, such kinetics are consistent with collision-induced intramolecular V-V energy transfer. Figures 8 and 9 have significant mechanistic implications, concerning the CIQCB bath kinetics (whether they are collision-induced and, if so, intramolecular or intermolecular), as discussed in Section IV below.…”

Section: Ir-uv Dr Spectra and Kinetics With Uv Probe At ∼299 Nmmentioning

confidence: 71%

Rovibrational Energy Transfer in the 4ν_CHManifold of Acetylene, Viewed by IR−UV Double-Resonance Spectroscopy. 4. Collision-Induced Quasi-Continuous Background Effects

et al. 2006

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The 4nu(CH) rovibrational manifold around 12 700 cm(-1) in the electronic ground state, X, of acetylene (C2H2) is monitored by time-resolved infrared-ultraviolet double-resonance (IR-UV DR) spectroscopy. An IR laser pulse initially prepares rotational J states, associated with the "IR-bright" (nu1 + 3nu3) or (1 0 3 0 0)0 vibrational combination level, and subsequent collision-induced state-to-state energy transfer is probed by UV laser-induced fluorescence. Anharmonic, l-resonance, and Coriolis couplings affect the J states of interest, resulting in a congested rovibrational manifold that exhibits complex intramolecular dynamics. In preceding papers in this series, we have described three complementary forms of the IR-UV DR experiment (IR-scanned, UV-scanned, and kinetic) on collision-induced rovibrational satellites, comprising both regular even-DeltaJ features and unexpected odd-DeltaJ features. This paper examines an unusual collision-induced quasi-continuous background (CIQCB) effect that is apparently ubiquitous, accompanying regular even-DeltaJ rovibrational energy transfer and accounting for much of the observed collision-induced odd-DeltaJ satellite structure; certain IR-bright (1 0 3 0 0)0 rovibrational states (e.g., J = 12) are particularly prominent in this regard. We examine the mechanism of this CIQCB phenomenon in terms of a congested IR-dark rovibrational manifold that is populated by collisional transfer from the nearly isoenergetic IR-bright (1 0 3 0 0)0 submanifold.

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“…Figure6. Calculated probability, ((F)), for long-range energy transfer for exact donor-acceptor resonance, = 0 (eq 5) and…”

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confidence: 99%

Vibrational Population Relaxation of Perylene in n-Alkanes. The Role of Solvent Local Structure in Long-Range Vibrational Energy Transfer

Jiang¹,

Blanchard²

1994

J. Phys. Chem.

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We have measured the vibrational population relaxation times of the Raman active v7 mode (1375 cm-') and(v7 + v15) combination mode (1733 cm-') of perylene in eight liquid n-alkanes using ultrafast stimulated emission spectroscopy. The vibrational population relaxation time of the perylene v7 mode ranges from -300 to < l o ps depending on the n-alkane solvent chain length, but there is no simple correspondence between alkane length and TI for v7. Energy transfer from the perylene v7 vibrational mode to a specific n-alkane solvent vibrational mode is dominated by long-range resonance coupling. The perylene (v7 + ~1 5 ) combination mode exhibits additional efficient relaxation pathways for different length n-alkanes. These data point collectively to short-range order in the n-alkane solvent surrounding perylene molecule. IntroductionThere have been a large number of recent studies focusing on intermolecular interactions in room temperature liquids because they are an important but ill-understood vehicle for many chemical processes.' Principal among the difficulties associated with understanding intermolecular interactions in liquids is the rapidly changing spatial relationship between neighboring molecules and elucidation of the various pathways in which energy can be exchanged. There are a variety of length scales on which these questions can be addressed, and the information provided by experiments aimed at interrogating the various length scales, taken collectively, can provide insight into local, transient organization in liquids.The advent of lasers capable of producing short pulses of light has allowed the direct investigation of energy and structural relaxation processes in liquids. A common theme in many laserbased experiments on liquid-phase dynamics is the use of a "probe" molecule that absorbs and (sometimes) emits light at wavelengths accessible to pulsed lasers. For almost all of these experiments, there is excess energy remaining in the probe molecule after the information of interest has been extracted, and at least some of this excess energy is stored as vibrational energy. In low-pressure gas-phase experiments, where an excited molecule is comparatively isolated from its neighbors, vibrational energy will dissipate slowly within the molecule to lower energy modes according to the extent of anharmonic coupling between the vibrational modes.2 For probe molecules in liquids, intramolecular relaxation is often less important than direct intermolecular relaxation because the number of collisional interactions with the surrounding medium is large and individual molecules are in closer spatial proximity to one a n~t h e r .~.~ In solution, excess vibrational energy within a molecule can be dissipated directly into the surroundings, sometimes very efficiently. Intermolecular vibrational population relaxation processes include energy transfer from solute vibrational modes into the translational, vibrational, and rota-* Author to whom correspondence should be addressed. @ Abstract published in Advance ACS Ab...

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Possible model states for the B phase of superfluid³He

Cited by 8 publications

References 11 publications

The collisional deactivation of highly vibrationally excited pyrazine by a bath of carbon dioxide: Excitation of the infrared inactive (100), (020), and (0220) bath vibrational modes

The collisional deactivation of highly vibrationally excited pyrazine by a bath of carbon dioxide: Excitation of the infrared inactive (100), (020), and (0220) bath vibrational modes

Rovibrational Energy Transfer in the 4ν_CHManifold of Acetylene, Viewed by IR−UV Double-Resonance Spectroscopy. 4. Collision-Induced Quasi-Continuous Background Effects

Vibrational Population Relaxation of Perylene in n-Alkanes. The Role of Solvent Local Structure in Long-Range Vibrational Energy Transfer

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Possible model states for the B phase of superfluid3He

Cited by 8 publications

References 11 publications

The collisional deactivation of highly vibrationally excited pyrazine by a bath of carbon dioxide: Excitation of the infrared inactive (100), (020), and (0220) bath vibrational modes

The collisional deactivation of highly vibrationally excited pyrazine by a bath of carbon dioxide: Excitation of the infrared inactive (100), (020), and (0220) bath vibrational modes

Rovibrational Energy Transfer in the 4νCHManifold of Acetylene, Viewed by IR−UV Double-Resonance Spectroscopy. 4. Collision-Induced Quasi-Continuous Background Effects

Vibrational Population Relaxation of Perylene in n-Alkanes. The Role of Solvent Local Structure in Long-Range Vibrational Energy Transfer

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Possible model states for the B phase of superfluid³He

Rovibrational Energy Transfer in the 4ν_CHManifold of Acetylene, Viewed by IR−UV Double-Resonance Spectroscopy. 4. Collision-Induced Quasi-Continuous Background Effects