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Journal ArticleDOI

Infrared Spectra and Characteristic Frequencies of Inorganic Ions

19 Aug 1952-Analytical Chemistry (American Chemical Society)-Vol. 24, Iss: 8, pp 1253-1294
TL;DR: The No. 10123 1quart "Success" can as discussed by the authors dispenses solvent by finger pressure on the valve, which then closes upon release of the pressure, as indicated in the accompanying figure.
Abstract: use and allows it to dispense no more solvent than is needed when the swab-stick is dipped into it like a pen into an inkwell. Available in 4 oz., 6 oz., and 8 oz. sizes, the price ranges from $3. 50 to $3. 75. This same company also advertises a model No. 10123 1quart "Success" can which dispenses solvent by finger pressure on the valve, which then closes upon release of the pressure, as indicated in the accompanying figure. There is also a plunger can of I-pint size that dispenses solvent by pressure on the plunger. Price for the first type of can is about $8, for the second, about $7.
Citations
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Journal ArticleDOI
TL;DR: A strategy to entrap polysulfides in the cathode that relies on a chemical process, whereby a host--manganese dioxide nanosheets serve as the prototype--reacts with initially formed lithium polysolfides to form surface-bound intermediates, which are among the best reported to date.
Abstract: The lithium-sulfur battery is receiving intense interest because its theoretical energy density exceeds that of lithium-ion batteries at much lower cost, but practical applications are still hindered by capacity decay caused by the polysulfide shuttle. Here we report a strategy to entrap polysulfides in the cathode that relies on a chemical process, whereby a host--manganese dioxide nanosheets serve as the prototype--reacts with initially formed lithium polysulfides to form surface-bound intermediates. These function as a redox shuttle to catenate and bind 'higher' polysulfides, and convert them on reduction to insoluble lithium sulfide via disproportionation. The sulfur/manganese dioxide nanosheet composite with 75 wt% sulfur exhibits a reversible capacity of 1,300 mA h g(-1) at moderate rates and a fade rate over 2,000 cycles of 0.036%/cycle, among the best reported to date. We furthermore show that this mechanism extends to graphene oxide and suggest it can be employed more widely.

1,625 citations

Journal ArticleDOI
TL;DR: In this paper, it is concluded that no probe can be universally used and that both acid probes can lead on highly basic metal oxides to polydentate (bulk) species which do not result from their adsorption but from their reaction with the given oxide.

684 citations

Journal ArticleDOI
TL;DR: In this article, the characteristic frequencies of 52 metals have been studied in the region 700-240 cm−1 and a particle size of 10 μ or smaller was found to give the best representative spectrum.

501 citations

Journal ArticleDOI
TL;DR: In this article, the long wavelength optical phonons of ionic crystals give rise to dipole-dipole forces, whose long range nature causes the vibrations to depend on the size and shape of the crystal sample.
Abstract: The long wavelength optical phonons of ionic crystals give rise to dipole-dipole forces, whose long range nature causes the vibrations to depend on the size and shape of the crystal sample. This dependence affects significantly most spectral properties of all crystals whose dimensions are of the order of or shorter than the wavelength of reststrahlen (characteristically several tens of micrometres). In experimental work in which the infrared properties of ionic crystals were examined on small samples, in powder form or in colloidal suspension or in the shape of thin layers, the peculiarities due to size and shape were not always properly recognized. The infrared frequencies of the material which are derived with disregard to these peculiarities may be in error by some tens of wavenumbers. In the experimental section of the review we interpret the general characteristics of the experimental spectra and analyse in detail some representative infrared measurements in the light of the theory. The theory of optical vibrations which takes account of the finiteness of the specimen is formulated firstly in general terms and then by special reference to samples which have one, two or three dimensions short (slab, cylinder and sphere-like geometries). Synthetic spectra are drawn whose characteristic features are interpreted in terms of bulk and surface modes. In the theory retardation effects, i.e. the coupling between lattice and electromagnetic waves, are also included, and the quantized modes are combinations of these, i.e. polaritons. For tiny crystallites of such size that the characteristic infrared radiation wavelength is much larger than the sample size, retardation effects can be neglected. The theory becomes much simpler and the spectrum sharper. Some of the absorption peaks are due to optical surface modes, and their positions are simply related to the characteristic shapes of the crystallites. The theory is so presented as to provide a practical aid in the correlation of spectra with sample shape. The consequences on the spectra of other, less common variables of experiments, for example, the refractive index of the environments, are also calculated. The role of optical surface modes in Raman - and electron - scattering is then discussed. Simple geometrical arrangements of small sized crystals enable the spectra of surface modes to be scanned.

456 citations

References
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Journal ArticleDOI
N. B. Colthup1
TL;DR: In this article, a chart giving probable positions of characteristic infra-red absorption bands for certain molecular groupings is presented, and the reliability of the various correlations is discussed in the text.
Abstract: This paper presents a chart giving probable positions of characteristic infra-red absorption bands for certain molecular groupings. Both original and published data were used in its preparation. The reliability of the various correlations is discussed in the text.

494 citations

Journal ArticleDOI
TL;DR: In this paper, the infra-red spectra of thin non-scattering films of NH4Cl and ND4Cl were obtained at 28°, −78° and −190°C.
Abstract: The infra‐red spectra of thin non‐scattering films of NH4Cl and ND4Cl were obtained at 28°, −78° and −190°C. A convenient low temperature transmission type cell usable for such films is described. No indication of fine structure due to free rotation of the NH4+ ions was found. Instead, evidence is presented for the existence, both above and below the λ‐point, of a torsional lattice mode involving the NH4+ ions. The limiting frequencies of the torsional oscillations were observed at about 390 and 280 cm−1 for NH4Cl and ND4Cl, respectively. These values agree quite well with the frequencies calculated on the basis of a purely electrostatic potential function. The spectra of the low temperature modifications indicate strongly that the structures belong to the space group Td1 in which the NH4+ ion symmetry is Td. Of the eight observed bands, two are assigned to the triply degenerate fundamentals ν3 and ν4, one to the overtone 2ν4, one to the combination ν2+ν4 which resonates strongly with ν3, one to the combi...

322 citations

Journal ArticleDOI

38 citations

Journal ArticleDOI
TL;DR: In this paper, a breve revue montre que les spectres d'absorption infrarouges sont capables de fournir des renseignations.

9 citations