Showing papers on "Infrared spectroscopy published in 1974"
Book•
01 Jan 1974
TL;DR: The use of vibrational spectroscopy as a tool in identifying mineral species and in deriving information concerning the structure, composition and reactions of minerals and mineral products is discussed in this paper.
Abstract: The principal concern of this book is the use of vibrational spectroscopy as a tool in identifying mineral species and in deriving information concerning the structure, composition and reactions of minerals and mineral products. This does not mean that the approach is purely empirical; some theoretical understanding of the vibrational spectra of solids is essential to an assessment of the significance of the variations in the spectra that can be found within what is nominally a single mineral species, but which usually includes a range of compositions and defect structures. Theory alone, however, can give only limited support to the mineral spectroscopist, and careful studies of well-characterized families of natural and synthetic minerals have played an essential role in giving concrete structural significance to spectral features. The publication of this book represents a belief that theory and practice have now reached a state of maturitity and of mutual support which justifies a more widespread application of vibrational spectroscopy to the study of minerals and inorganic materials. The wide area of theory and practice that deserves to be covered has required a careful selection of the subject matter to be incorporated in this book. Since elementary vibrational spectroscopy is now regularly included in basic chemistry courses, and since so many books cover the theory and practice of molecular spectroscopy, it has been decided to assume the very basic level of knowledge which will be found, for example, in the elementary introduction of Cross and Jones (1969). With this assumption, it has been possible to concentrate on those aspects that are peculiar to or of particular significance for mineral spectroscopy.
2,720 citations
01 Jan 1974
TL;DR: The use of vibrational spectroscopy as a tool in identifying mineral species and in deriving information concerning the structure, composition and reactions of minerals and mineral products is discussed in this paper.
Abstract: The principal concern of this book is the use of vibrational spectroscopy as a tool in identifying mineral species and in deriving information concerning the structure, composition and reactions of minerals and mineral products. This does not mean that the approach is purely empirical; some theoretical understanding of the vibrational spectra of solids is essential to an assessment of the significance of the variations in the spectra that can be found within what is nominally a single mineral species, but which usually includes a range of compositions and defect structures. Theory alone, however, can give only limited support to the mineral spectroscopist, and careful studies of well-characterized families of natural and synthetic minerals have played an essential role in giving concrete structural significance to spectral features. The publication of this book represents a belief that theory and practice have now reached a state of maturitity and of mutual support which justifies a more widespread application of vibrational spectroscopy to the study of minerals and inorganic materials. The wide area of theory and practice that deserves to be covered has required a careful selection of the subject matter to be incorporated in this book. Since elementary vibrational spectroscopy is now regularly included in basic chemistry courses, and since so many books cover the theory and practice of molecular spectroscopy, it has been decided to assume the very basic level of knowledge which will be found, for example, in the elementary introduction of Cross and Jones (1969). With this assumption, it has been possible to concentrate on those aspects that are peculiar to or of particular significance for mineral spectroscopy.
489 citations
248 citations
TL;DR: In this article, the infrared spectra of carbon monoxide adsorbed on supported PdAg alloys were investigated, and three CO absorption bands were observed on Pd and on the alloys at ~2060, 1960 and 1920 cm−1.
213 citations
TL;DR: In this article, a minimum value for the band gap of 6.4 ± 0.5 eV was obtained from soft X-ray spectra of cubic boron nitride crystals.
156 citations
TL;DR: In this article, the effects of strong electric fields on equilibrium nuclear configurations, vibration frequencies and vibrational transition intensities were examined for the carbon monoxide molecule in axial fields and the results were applied to interpretation of infrared absorption measurements for weakly adsorbed CO, and infrared and CO bond-length measurements for carbonyl complexes.
132 citations
TL;DR: In this paper, it is shown that infrared reflectances are proportional to the concentrations of the vibrational species causing them, and the influence of phase separation on reflection spectra is also discussed.
Abstract: It is predicted theoretically and justified experimentally that infrared reflectances are proportional to the concentrations of the vibrational species causing them. In the binary Li2O-, Na2O-, and K2O-SiO2 glasses used in this study, the reflection peaks have been assigned to vibrations of single silicon-oxygen tetrahedra in different symmetry environments caused by the presence of alkali ions. Care has been taken here in recording the spectra of high alkali glasses to prevent chemical reactions with water vapor in the atmosphere. The influence of phase separation on reflection spectra is also discussed.
125 citations
TL;DR: In this paper, a density of coupled oscillator pseudo phonon states was assigned to the optical phonon spectrum of the crystalline form of the material, which assignment was shown to be consistent with experimental linear vibrations of ω0 with Δω1/2 and ω02 with, the integrated absorbance, within the complete set of glasses.
Abstract: The far infrared spectrum of each ionic metal‐metaphosphate glass, (MPO3)n (M = Li, Na, K, Rb, Cs) and [M(PO3)2]n (M = Ca, Sr, Ba), contains a broad absorption band whose peak frequency, ω0, and halfbandwidth, Δω1/2, are strongly dependent on the mass and charge of the glass‐modifying cation. Each such band, which appears as the envelope of the optical phonon spectrum of the crystalline form of the material, is assigned to a density of coupled oscillator pseudo phonon states, which assignment is shown to be consistent with experimental linear vibrations of ω0 with Δω1/2 and of ω02 with , the integrated absorbance, within the complete set of glasses. The net effect of coupling the oscillators in the vitreous (disordered) system is equivalently treated as a single damped harmonic oscillator. The damping coefficient, b = μΔω1/2, is constant in each series as is the complex part of the refractive index at ω0, κ(ω0), and the Lorentzian band is used to compute the force constant, F, b, and T, 0,...
119 citations
TL;DR: In this paper, the vibrational assignment of HO2 and DO2 to the weak 0-0 mode at 1123 cm−1 Normal coordinate calculations using HO 2 and DO 2 oxygen isotopic frequencies gave excellent agreement with the observed data The bonding in HO2 is suggested to be largely covalent.
Abstract: Matrix reactions of H and D atoms from a microwave discharge source with oxygen molecules diluted in argon have produced significantly higher yields of HO2 and DO2 than the previous photolysis methods Oxygen isotopic enrichment confirmed the previous vibrational assignments to HO2; significantly greater concentrations of DO2 allowed observation of the weak 0–0 mode at 1123 cm−1 Normal coordinate calculations using HO2 and DO2 oxygen isotopic frequencies gave excellent agreement with the observed data The bonding in HO2 is suggested to be largely covalent, in contrast to the ionic species Li+O2−
113 citations
TL;DR: In this paper, a study of the room-temperature infrared reflectance and Raman spectra has been made on a room temperature glass, and the dominant features of the two spectra are complementary with respect to frequency, and can be understood in terms of a molecular model in which the Ge atoms are fourfold coordinated and S atoms twofold coordinated.
Abstract: A study of the room-temperature infrared reflectance and Raman spectra has been made on a ${\mathrm{Ge}}_{0.30}$${\mathrm{S}}_{0.70}$ glass. The dominant features of the two spectra are complementary with respect to frequency, and can be understood in terms of a molecular model in which the Ge atoms are fourfold coordinated and S atoms twofold coordinated; the molecular structure in the model is a Ge${\mathrm{S}}_{4}$ tetrahedron. Splittings of the bond-stretching modes into two components provide a measure of the intermolecular coupling. Density-of-states effects are clearly present in the low-frequency portions of the spectra, particularly in the Raman spectrum where the bond-bending optic modes and acoustic modes contribute to a continuum of scattering.
107 citations
TL;DR: In this paper, the mid-infrared spectra of the oxides of Ce, Pr, Sm, Eu, Tb, and Th have been obtained by vaporizing the solid oxides and trapping the vapor species in argon matrices.
Abstract: The midinfrared spectra of the oxides of Ce, Pr, Sm, Eu, Tb, and Th have been obtained by vaporizing the solid oxides and trapping the vapor species in argon matrices. On the basis of oxygen‐18 isotope shifts, a linear structure has been determined for PrO2, and nonlinear structures for CeO2, TbO2, and ThO2. Values of ωe and ωeχe have been determined for the monoxides of Pr, Eu, Tb, and Th from the small deviations between the observed and the theoretical harmonic isotope shifts.
TL;DR: In this article, the effect of chelation on the ligand group frequencies and the stability order of the chelates are discussed, and the observed frequencies have been made to specific group vibrations by comparison with the spectra of related compounds.
TL;DR: In this paper, the infrared spectra of benzoic acid and benzosic acid d were obtained in the range of temperatures from liquid nitrogen to liquid helium and the C=O stretching band at 1688 cm−1, the strongest absorption band of this compound in the over-all infrared region at room temperature, decreases in intensity with decreasing temperature.
Abstract: Infrared spectra of benzoic acid and benzoic acid‐d were obtained in the range of temperatures from liquid nitrogen to liquid helium The C=O stretching band at 1688 cm−1, the strongest absorption band of this compound in the over‐all infrared region at room temperature, decreases in intensity with decreasing temperature and disappears near liquid‐helium temperatures Near this temperature, also lost was the band at 959 cm−1 which has been assigned to the OH out‐of‐plane vibration For the deuterated species both bands at 1689 and 1679 cm−1, which have been interpreted as splitting due to Fermi resonance of the C=O stretching vibration, were lost Close to the positions of these lost bands, alternative bands, which are assignable to the same modes and increase in intensity with decreasing temperature, are found The results support the postulate proposed in our earlier work that two distinct equilibrium configurations of benzoic acid dimer coexist in the crystal
TL;DR: The vibrational frequencies of polyatomic molecules derive from the masses of the linked atoms, their geometric interrelationships, and the forces due to deviation from equilibrium bond configurations as discussed by the authors.
Abstract: The interatomic distances within molecules fluctuate cyclically about average values through one or more simultaneous vibrational motions—stretching, deformation, torsion, etc. When such motions change the dipole moment of a given bond, its electric field oscillates at the same frequency as the bond vibration (1010–1011 Hz, corresponding to wavelengths of 2–20 μ). Moreover, upon exposure of the bond to electromagnetic radiation of the same frequency as the dipole oscillation, it absorbs some of the radiant energy in a quantal fashion, promoting it to a higher energy state. The energies involved in IR spectroscopy are of the order of tenths of electron volts and, unlike ultraviolet and visible light, IR radiation effects only vibrational and rotational transitions within molecules. Indeed, at normal temperatures, IR absorption usually arises principally from vibrational rather than rotational transitions. IR spectroscopy deals with these processes at ranging levels of sophistication. The vibrational frequencies of polyatomic molecules derive from (a) the masses of the linked atoms, (b) their geometric interrelationships, and (c) the forces due to deviation from equilibrium bond configurations.
01 Dec 1974
TL;DR: In this paper, the adsorption and reaction of acetic acid have been studied using the technique of reflection-absorption infrared spectroscopy, and the results indicate that at ambient temperatures acetic acids adsorbs on cuprous oxide to form a vacuum stable (10−7 Torr), thick (several hundred angstrom) film having an ionic lattice comprised primarily of discrete protons and acetate ions.
Abstract: The adsorption and reaction of acetic acid have been studied using the technique of reflection-absorption infrared spectroscopy. Evaporated copper films on both glass and gold substrates have been oxidized to cuprous oxide and allowed to interact with gaseous acetic acid. The results indicate that at ambient temperatures acetic acid adsorbs on cuprous oxide to form a vacuum stable (10−7 Torr), thick (several hundred angstrom) film having an ionic lattice comprised primarily of discrete protons and acetate ions. At higher temperatures (near 200°C) incorporation of copper ions into the film occurs with apparent partial decomposition of the acetate ion. The general implications of these results on the understanding of the mechanisms of attack of organic acids on metal-metal oxide surfaces is discussed.
TL;DR: The structure of nickel squarate dihydrate, NiC4O4 · 2H2O, has been investigated by initial susceptibility measurements, infrared spectroscopy, and single crystal x-ray diffraction techniques as mentioned in this paper.
Abstract: The structure of nickel squarate dihydrate, NiC4O4 · 2H2O, has been investigated by initial susceptibility measurements, infrared spectroscopy, and single crystal x‐ray diffraction techniques The results indicate that the structure consists of Ni ions situated at the centers of the edges of a cube, with squarate ions in the cube faces Each nickel is roughly octahedrally coordinated by four squarate oxygens, and by two water oxygens The lattice constants were found to be a = b = c =80685A, with α = β = γ = 90° within experimental accuracy The structure was found to be noncubic A spin‐orbit coupling parameter of −280 (30) cm−1, which is 86% of the free ion value, is obtained from the magnetic and spectroscopic results The structure of this compound, which is isostructural with the Mn(II), Fe(II), and CO(II) squarates, is different than that proposed by two other sets of workers All crystals investigated were found to be macroscopically twinned, and a reason for such twinning is proposed
TL;DR: In this article, the interaction of oxygen with 2-propanol and acetone adsorbed on MgO has been studied by infrared spectroscopy as well as analysis of reaction products.
TL;DR: In this article, the authors used thin layer chromatography on AgNO3-silicic acid to identify the major peaks with equivalent chain length values of 27.08 and 27.74.
Abstract: Fatty acid analysis of the total lipids from the marine spongeMicrociona prolifera by gas liquid chromatography on an EGSS-X column revealed two major peaks with equivalent chain length values of 27.08 and 27.74. Each of these components was isolated as a separate band by thin layer chromatography on AgNO3-silicic acid. Characterization of the two unknowns by IR spectroscopy, NMR, hydrogenation, and gas liquid chromatography revealed that the unknown acids weren-26∶2 andn-26∶3 containing only nonmethylene interruptedcis-double bonds. Reductive ozonolysis identified the 26∶2 ascis-5,cis-9-hexacosadienoic acid and the 26∶3 ascis-5,cis-9,cis-19-hexacosatrienoic acid. Analysis of the fatty acid composition ofMicrociona total lipids showed 14% 26∶2 and 31% 36∶3. The neutral lipids, phosphatidylethanomaline, and phosphatidylserine all contained >41% C26 acids; but only 4% C26 was present in the phosphatidylcholine.
TL;DR: In this paper, the infrared spectra of gaseous, liquid and solid methyl acetate and its deuterium derivatives have been investigated from 4000 to 200 cm−1, but the methyl torsional modes were not resolved.
TL;DR: In this paper, the infrared absorption in KCl single crystals near 10.6 μm has been studied using calorimetric techniques with fixed-frequency and tunable CO2 laser sources.
Abstract: The infrared absorption in KCl single crystals near 10.6 μm has been studied using calorimetric techniques with fixed‐frequency and tunable CO2 laser sources. By use of crystals grown in a reactive CCl4 atmosphere, with surfaces carefully prepared by chemical polishing, it is possible to obtain absorption coefficients of 0.0002 cm−1 or less in samples several centimeters thick. This residual absorption is composed of a surface and a bulk part. It is possible to show that the bulk absorption approaches the estimated intrinsic limit of 0.00008 cm−1. An absorption band near 9.8 μm is present in all samples examined and appears to be largely associated with the surface.
TL;DR: In this paper, the infrared spectrum of the resulting deposit was basically identical to that for CO and N2O isolated in an argon matrix in the absence of alkali metal atoms.
TL;DR: In this article, the in situ photolysis of molecular fluorine and NO2 molecules in nitrogen matrices at 8°K yields the FN-bonded nitryl fluoride, FNO2, as the primary reaction product.
Abstract: The in situ photolysis of molecular fluorine and NO2 molecules in nitrogen matrices at 8°K yields the FN‐bonded nitryl fluoride, FNO2, as the primary reaction product. However, controlled fluorine atom diffusion at 20°K, in the absence of photolytic radiation, results in the formation of the highly reactive, FO‐bonded, nitrosyl hypofluorite, ONOF. Infrared absorptions at 1716.4, 1199.9, 702.3, and 411.9 cm−1 were assigned to this species, which was shown from 15N and 18O isotopic studies to contain two nonequivalent oxygen atoms. The ONOF molecule undergoes intramolecular photorearrangement at wavelengths below 400 nm to produce the more stable FNO2 form.
Journal Article•
TL;DR: Electrical measurement of the second derivative of voltage with respect to current, as a function of applied voltage, then gives a spectrum of vibrational modes equivalent to an infrared or Raman spectrum, but with the use of only micrograms of sample.
Abstract: Metal-insulator-metal electron tunnel junctions can be doped with a solution of an organic compound by placing a drop of the solution on the insulator and spinning of the excess. Electrical measurement of the second derivative of voltage with respect to current, as a function of applied voltage, then gives a spectrum of vibrational modes equivalent to an infrared or Raman spectrum, but with the use of only micrograms of sample.
TL;DR: In this paper, the infrared spectra of polycrystalline K2SnCl4•H2O at different degrees of deuteration were recorded between 4000 and 300 cm−1 at temperatures between 30 and −160 °C.
Abstract: Infrared spectra of polycrystalline K2SnCl4•H2O at different degrees of deuteration were recorded between 4000 and 300 cm−1 at temperatures between 30 and −160 °C. The spectra are consistent with the crystal structure proposed by Kamenar and Grdenic. The water molecules are all equivalent and asymmetric. They are sufficiently well separated from one another for the dynamic coupling of vibrations to be negligible. Both hydrogens of the water molecule participate in hydrogen bonding; one of the hydrogen bonds is weak and bifurcated. Positional parameters of the hydrogen atoms have been calculated using supplementary information from available n.m.r. studies. Infrared spectral characteristics of water molecules engaged in bifurcated hydrogen bonding are discussed.
TL;DR: In this article, a comparison of electronic absorption bands of Salicylaldehyde salicylhydrazone (SSH) and metal complexes showed the presence of ligand-metal charge transfer bands.
TL;DR: In this article, room temperature infrared spectra are presented, which show major changes in the reststrahl region of a gallium arsenide implant with nitrogen ions at 1-3 MeV and fluences between 3.3×1013 and 2.0×1017 ions/cm2.
Abstract: Gallium arsenide has been implanted with nitrogen ions at 1–3 MeV and fluences between 3.3×1013 and 2.0×1017 ions/cm2. Room‐temperature infrared spectra are presented which show major changes in the reststrahl region. A sample having the highest fluence was isochronally annealed with 2‐h 100°C steps from 200 to 600°C, and the implantation‐induced reflectivity changes are annealed by 600°C. Changes of the dispersion parameters were determined by Kramers‐Kronig analysis as well as by curve fitting with classical dispersion (CD) analysis. Examples of dispersion parameters obtained by different analyses are compared and their validity is discussed. The data of nonimplanted and samples implanted with fluence up to 3.3×1014 ions/cm2 can be satisfactorily fitted with CD analysis assuming the material to be optically homogeneous. With this assumption, attempts to fit the data of samples with fluences ≥3.3 ×1015 ions/cm2 were unsuccessful. By extending the CD analysis to a layer model a reasonable fit was achieved...