scholarly journals Прямое наблюдение квазилокализованной низкочастотной колебательной моды в спектре возбуждения флуоресценции одиночной примесной молекулы в полимерной матрице-=SUP=-*-=/SUP=-

2019 ◽  
Vol 126 (1) ◽  
pp. 53
Author(s):  
А.О. Савостьянов ◽  
И.Ю. Еремчев ◽  
А.А. Горшелев ◽  
С.В. Орлов ◽  
А.С. Старухин ◽  
...  
Keyword(s):  
Vibrational Mode ◽  
Excited Electronic State ◽  
Low Frequency ◽  
Local Environment ◽  
Fluorescence Excitation Spectrum ◽  
Elementary Excitation ◽  
Impurity Molecule ◽  
Fluorescence Excitation ◽  
Mode Spectrum ◽  
Electron Phonon Interaction

AbstractThe possibility of direct observation of a quasi-localized elementary excitation of the phonon type in polyisobutylene has been demonstrated by detecting the fluorescence excitation spectrum of a Mg‑tetrazaporphyrin single probe molecule in a wide spectral range at a temperature of 6 K. The parameters of the quasilocalized low-frequency vibrational mode have been measured—the frequency (energy) in the case, when impurity molecule is in excited electronic state (ω_ e = 13.94 ± 0.21 cm^–1) and the halfwidth of the mode spectrum (γ = 3.82 ± 0.66 cm^–1). The measured energy of the low-frequency vibrational mode coincides with the position of a boson peak maximum in the spectrum of vibrational states of the polymer, which indicates that the weak coupling approach can be applied to the considered case of the electron–phonon interaction of an organic dye molecule with the local environment in a polymer matrix.

The S1 ← S0 fluorescence excitation spectrum and structure of propanal in the S1 excited electronic state

2016 ◽  
Vol 18 (22) ◽  
pp. 15244-15250 ◽  
Author(s):  
I. A. Godunov ◽  
N. N. Yakovlev ◽  
R. V. Terentiev ◽  
D. V. Maslov ◽  
A. V. Abramenkov
Keyword(s):  
Electronic State ◽  
Excitation Spectrum ◽  
Excited Electronic State ◽  
Fluorescence Excitation Spectrum ◽  
Conformational Structure ◽  
Fluorescence Excitation

Propanal molecule in the S1 excited electronic state has complex conformational structure.

Low frequency Raman spectra of the liquid and plastic crystal phases of O2, N2, CO, and of Ar crystals with these molecules as guests

1982 ◽  
Vol 60 (9) ◽  
pp. 1358-1364 ◽  
Author(s):  
N. H. Rich ◽  
M. J. Clouter ◽  
H. Kiefte ◽  
S. F. Ahmad
Keyword(s):  
Single Crystals ◽  
Raman Spectra ◽  
Phonon Mode ◽  
Low Frequency ◽  
Impurity Molecule ◽  
Spectral Features ◽  
Background Impurity ◽  
Crystal Phases ◽  
Distinct Features ◽  
Frequency Feature

Low frequency Raman spectra of single crystals of orientationally disordered phases of oxygen, nitrogen, and carbon monoxide, and spectra of those substances as liquids show two linear segments in semi-log plots. Slopes of the higher frequency segments are nearly equal for all cases; slopes of the lower frequency segments are particular to the substance and are nearly the same in both liquid and crystal for O2 and CO. Spectra of single crystals of argon doped with O2, N2, or CO show two distinct features superimposed on a sloping background. Impurity molecule reorientation apparently accounts satisfactorily for all spectral features, but translation–rotation coupling may allow a contribution to the higher frequency feature arising from a local phonon mode in argon.

A Raman study of B203 through the liquid-glass transition range

1992 ◽  
Vol 02 ◽  
pp. C2-265-C2-270
Author(s):  
A. K. HASSAN ◽  
L. M. TORELL ◽  
L. BORJESSON
Keyword(s):  
Glass Transition ◽  
Correlation Length ◽  
Room Temperature ◽  
Vibrational Mode ◽  
Low Frequency ◽  
Boson Peak ◽  
Transition Range ◽  
Structural Correlation ◽  
Raman Study ◽  
Correlation Range

The low frequency Raman spectrum of B203 and the boroxol ring vibrational mode at 808 cm-1 have been studied from room temperature to 1273 K as the glass transforms to a melt. Both the low frequeney "boson" peak and the boroxol mode are markedly influenced by the glass transition. Raising the temperature above Tg the strength of the 808 cm-1 mode decreases linearly indicating the Similar behavior of the boroxol ring concentration. The boson peak shows a different temperature behavior, which mirrors that of the sound velo city. The structural correlation length demostrates the same correlation range in the liquid and the glass. The results, when compared with neutron diffraction measurements contradict a recently proposed relation between the "boson correlation length" and the position of the first sharp diffraction peak of the structure factor.

Donor-acceptor complexes formed by perfluoro-organo bromides and iodides with nitrogenous and other bases. II. Band shapes and widths in the absorption spectrum of gaseous CF3I-N(CH3)3

1971 ◽  
Vol 24 (12) ◽  
pp. 2493 ◽  
Author(s):  
A Mishra ◽  
ADE Pullin
Keyword(s):  
Vibrational Mode ◽  
Low Frequency ◽  
Molecular Complexes ◽  
Wave Number ◽  
Centrifugal Distortion ◽  
Band Shape ◽  
Gaseous Mixtures ◽  
Factors Affecting ◽  
Donor Acceptor ◽  
Vibration Rotation

The absorption band centred at c. 77 cm-1 in gaseous mixtures of CF3I and N(CH3)3 previously reported and attributed to the N-I stretching mode of the complex CF3I-N(CH3)3 has been carefully re-examined. This band is of interest as an example of a low frequency ?dissociative type? vibrational mode of a weak molecular complex. The band is asymmetric and apparently structureless with a half intensity width at room temperature of 28-30 cm-1. The width of the band may be accounted for as arising from transitions vi + vi+1 where vi is the vibrational quantum number of the N-I stretching mode with vi up to c. 10 making appreciable contribution to the intensity on the low wave-number side. Centrifugal distortion in the complex is considered. Centrifugal stretching and consequent weakening of the bond may shift the band envelope 2-3 cm-1 to lower wave numbers. Assessment of these and other factors affecting the band shape suggest that the fundamental frequency is probably c. 90 cm-1. The band shape of the vibrational mode of the complex at c. 272 cm-1 is briefly discussed. Many of the considerations presented in this paper should apply to vibration-rotation band shapes in other weak molecular complexes. Some general consequences of anharmonicity for the interpretation of the spectra of weak molecular complexes are discussed.

Two-Photon Fluorescence Excitation Spectrum of 1,6-Methano-[10]annulene

2000 ◽  
Vol 104 (28) ◽  
pp. 6566-6572 ◽  
Author(s):  
Lorenzo Catani ◽  
Cristina Gellini ◽  
Laura Moroni ◽  
Pier Remigio Salvi
Keyword(s):  
Excitation Spectrum ◽  
Fluorescence Excitation Spectrum ◽  
Fluorescence Excitation ◽  
Two Photon ◽  
Two Photon Fluorescence ◽  
Photon Fluorescence
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