Fermi-Resonance Minima in the Vibrational Spectrum of Water in Crystalline Hydrates

1975 ◽  
Vol 53 (24) ◽  
pp. 3837-3840 ◽  
Author(s):  
David A. Othen ◽  
Osvald Knop ◽  
Michael Falk
Keyword(s):  
Low Temperature ◽  
Vibrational Spectrum ◽  
Infrared Absorption ◽  
Narrow Band ◽  
Fermi Resonance ◽  
Condensed Phases ◽  
Spectral Features ◽  
Bending Vibration ◽  
Absorption Features ◽  
Crystalline Hydrates

The infrared absorption and Raman spectra of polycrystalline tetrachlorocuprate(II) dihydrates M2CuCl4.2H2O (M = K, Rb, Cs, NH4) contain minima in the OH stretching region which sharpen at low temperature. These minima are shown to be 'Evans holes', or negative absorption features, caused by Fermi resonance between the broad and intense H2O stretching fundamental V1 and a relatively narrow band due to the overtone of the H2O bending vibration 2V2. Our findings confirm that Fermi resonance can lead to unusual spectral features, which must be taken into account in the analysis of the stretching region of the spectra of H2O and D2O in condensed phases, as has been done by Scherer etal. for the spectrum of liquid water.

scholarly journals Surface-enhanced infrared absorption studies towards a new optical biosensor

2016 ◽  
Vol 7 ◽  
pp. 1736-1742 ◽  
Author(s):  
Lothar Leidner ◽  
Julia Stäb ◽  
Jennifer T Adam ◽  
Günter Gauglitz
Keyword(s):  
Infrared Absorption ◽  
Resonance Effect ◽  
Optical Biosensor ◽  
Fermi Resonance ◽  
Infrared Range ◽  
Bending Vibration ◽  
Thickness Change ◽  
Additional Information ◽  
Surface Enhanced ◽  
Stretching Vibration

Reflectometric interference spectroscopy (RIfS), which is well-established in the visual regime, measures the optical thickness change of a sensitive layer caused, e.g., by binding an analyte. When operated in the mid-infrared range the sensor provides additional information via weak absorption spectra (fingerprints). The originally poor spectra are magnified by surface-enhanced infrared absorption (SEIRA). This is demonstrated using the broad complex fluid water band at 3300 cm−1, which is caused by superposition of symmetric, antisymmetric stretching vibration, and the first overtone of the bending vibration under the influence of H-bonds and Fermi resonance effect. The results are compared with a similar experiment performed with an ATR (attenuated total reflectance) set-up.

scholarly journals Structural and mineralogical features of diamond from M. V. Lomonosov deposit (Arkhangelsk province): new data and their interpretation

2019 ◽  
Vol 486 (6) ◽  
pp. 695-698
Author(s):  
G. Yu. Kriulina ◽  
E. A. Vasilev ◽  
V. K. Garanin
Keyword(s):  
Low Temperature ◽  
Infrared Absorption ◽  
Thermal History ◽  
The Third ◽  
Diamond Crystals ◽  
Absorption Features ◽  
Model Temperature

In the deposit n.a. Y. M. Lomonosov three groups of diamond crystals were distinguished on the base of morphology, photoluminescence, infrared absorption features and the thermal history. The crystals of the first group are octahedrons with minor signs of dissolution. In the first group, crystals have a high proportion of nitrogen in the Bform and the high model temperature. The crystals of the second type is highly resorbed dodecahedroids, they has low proportion of nitrogen in B form. The third group consists of crystals with the low temperature C defects, they are cuboids and resorbed tetrahexahedroids. These patterns indicate the polygenicity of the diamond in the deposit after M.V. Lomonosov.

Infrared absorption features for tetrahedral ammonia ice crystals

Icarus ◽  
1989 ◽  
Vol 80 (1) ◽  
pp. 220-223 ◽  
Author(s):  
Robert A. West ◽  
Glenn S. Orton ◽  
Bruce T. Draine ◽  
Earl A. Hubbell
Keyword(s):  
Infrared Absorption ◽  
Ice Crystals ◽  
Absorption Features

The Strengths of Near‐Infrared Absorption Features Relevant to Interstellar and Planetary Ices

2005 ◽  
Vol 620 (2) ◽  
pp. 1140-1150 ◽  
Author(s):  
P. A. Gerakines ◽  
J. J. Bray ◽  
A. Davis ◽  
C. R. Richey
Keyword(s):  
Infrared Absorption ◽  
Near Infrared ◽  
Absorption Features ◽  
Planetary Ices

Size and Shape Dependence of the Vibrational Spectrum and Low-Temperature Specific Heat of Au Nanoparticles

2013 ◽  
Vol 117 (47) ◽  
pp. 25160-25168 ◽  
Author(s):  
Huziel E. Sauceda ◽  
Fernando Salazar ◽  
Luis A. Pérez ◽  
Ignacio L. Garzón
Keyword(s):  
Low Temperature ◽  
Vibrational Spectrum ◽  
Specific Heat ◽  
Au Nanoparticles ◽  
Size And Shape ◽  
Shape Dependence ◽  
Low Temperature Specific Heat

scholarly journals Contribution of low-temperature single-molecule techniques to structural issues of pigment–protein complexes from photosynthetic purple bacteria

2018 ◽  
Vol 15 (138) ◽  
pp. 20170680 ◽  
Author(s):  
Alexander Löhner ◽  
Richard Cogdell ◽  
Jürgen Köhler
Keyword(s):  
Low Temperature ◽  
Single Molecule ◽  
Degrees Of Freedom ◽  
Protein Complexes ◽  
Purple Bacteria ◽  
Structural Models ◽  
Spectral Features ◽  
Light Harvesting Complexes ◽  
Pigment Protein Complexes ◽  
Photosynthetic Purple Bacteria

As the electronic energies of the chromophores in a pigment–protein complex are imposed by the geometrical structure of the protein, this allows the spectral information obtained to be compared with predictions derived from structural models. Thereby, the single-molecule approach is particularly suited for the elucidation of specific, distinctive spectral features that are key for a particular model structure, and that would not be observable in ensemble-averaged spectra due to the heterogeneity of the biological objects. In this concise review, we illustrate with the example of the light-harvesting complexes from photosynthetic purple bacteria how results from low-temperature single-molecule spectroscopy can be used to discriminate between different structural models. Thereby the low-temperature approach provides two advantages: (i) owing to the negligible photobleaching, very long observation times become possible, and more importantly, (ii) at cryogenic temperatures, vibrational degrees of freedom are frozen out, leading to sharper spectral features and in turn to better resolved spectra.

scholarly journals Infrared Spectra of the Ices at ≈4 K and the Interpretation of the v OD(D2O) Bands of Ices II and IX

1978 ◽  
Vol 21 (85) ◽  
pp. 694
Author(s):  
F. E. Bates ◽  
S. M. Jacobs ◽  
J. E. Bertie
Keyword(s):  
Infrared Absorption ◽  
Far Infrared ◽  
Fermi Resonance ◽  
Chemical Physics ◽  
Vibrational States ◽  
Infrared Band ◽  
Stretching Vibrations ◽  
First Time ◽  
Lattice Modes ◽  
Complete Interpretation

Abstract We have studied the infrared absorption by the OD stretching, v OD(D2O), and D2O rotational, v R(D2O), vibrations of fully deuterated ice II and ice IX at lo K, and the absorption by OD stretching vibrations, v OD (HDO), of HDO molecules isolated in ices Ih, II, and IX at 10 K. Calculations of the frequencies and relative intensities of the zero-wave-vector normal v OD(D2O) vibrations of ices II and IX have allowed the v OD(D2O) absorption to be assigned. Each component of the band is broad, even at 10 K, most probably because of Fermi resonance between the fundamental OD stretching vibrational states and the isoenergetic continuum of high-order overtone and combination states of the lattice modes. This work has yielded the most complete interpretation yet achieved of an infrared band due to the OH or OD stretching vibrations of a phase of ice. The far-infrared absorption by the translational vibrations of H2O and D2O ices Ih and Ic at 4.3 K has been measured, and has revealed differences between the spectra of ices III and Ic for the first time. Papers describing this work in full have been published in Journal of Chemical Physics, Vol. 67, No. 4, 1977, p. 1311-18, and Vol. 67, No. 6, 1977, p. 2445-48.

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