Showing papers in "Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy in 1971"

TL;DR: In this article, a set of band assignments for normal II-III spinels is proposed, which are based on the chemical properties of the octahedral, trivalent cation.

TL;DR: In this article, the laser-Raman spectra and i.r. spectra of polycrystalline cytosine were obtained and a valence force field with thirteen transferred and sixteen refined force constants was employed to calculate a total of forty-three frequencies.

TL;DR: In this article, a 32 parameter valence force field for methyl substituted benzenes has been derived from 303 observed frequencies of benzene, toluene, p-xylene, m -xylene and mesitylene and a number of their deuterated analogues.

TL;DR: In this article, the rotational structure of several bands reveal a Coriolis type coupling between nearly degenerate a' and a'fundamentals, and strong Fermi resonances of combination tones involving the torsional mode with fundamentals are found for the gas spectra.

TL;DR: In this paper, a valence force field is presented for the grouping R-CO-NH-R' where R and R' are CH 2 or CH 3, derived from the frequencies of N-methylacetanide, nylons, and some of the deuteroderivatives.

TL;DR: In this article, the problem of interpreting the i.r. spectrum of spinels is discussed and the validity of this approximation is discussed for different types (weak or strong) of vibrational interactions, and emphasis is put on the identification of the cations which are involved in either localized or complex vibrations.

TL;DR: In this article, the authors present a critical discussion of the data and interpretations actually published in the literature, and they show that the generally accepted interpretation relies on an oversimplified vibrational scheme, and also on too fragmentary experimental data.

TL;DR: In this article, a complete vibrational assignment is proposed on the basis of gas-phase band contours, depolarization ratios and dichroic ratios; it is found that although the molecule has C2 symmetry in all three states of aggregation, the liquid and vapour-phase spectra are explainable in terms of C2v pseudo-symmetry.

TL;DR: In this paper, a normal coordinate analysis was performed on chloro complexes employing a Urey-Bradley force field with resonance parameter and suitable general valence force field terms about the metal site.

TL;DR: In this article, values of all the fundamental frequencies are proposed for the fifteen substituted phenols, o -, m - or p -X C 6 H 4 OH (X = CH 3, F, Cl, Br or I), in the monomeric state utilizing i.r. (3650-50 cm −1 ) and Raman spectra.

TL;DR: In this paper, the infrared spectra of 2,2'-bipyridine and its deutero analogue were obtained from 4000 to 40 cm−1 and the absorption bands of these compounds were assigned by a comparison of their spectra to each other as well as to the structurally similar molecules: pyridine, 2-substituted pyridines and biphenyl.

TL;DR: In this article, the deconvolution problem encountered here is akin to problems met in other spectroscopic situations, e.g., the application of slit width corrections, the decomposition of overlapping absorption bands and finite energy-spread corrections in mass spectrometry.

TL;DR: In this paper, a simple procedure is described for the analysis of the vibrational spectrum of monoclinic crystals which permits the modes predicted by group theory to be unambiguously assigned.

TL;DR: In this article, the spectral properties of matrix-isolated trifluoroacetic acid species and triflooracetic anhydride are analyzed and it is shown that a very low barrier hinders internal rotation of the CF3 group in the acids and also indicates the probable absence of an equilibrium plane of symmetry in the monomers.

TL;DR: In this article, it was shown that photoelectron spectroscopy is of considerable value in the interpretation of Raman and infrared spectra, and new assignments were made for the symmetric "ring distorting" vibrations in furan, pyrrole and cyclo pentadiene.

TL;DR: In this paper, the skeleton bending and stretching properties of tri-and diphenyltin compounds are discussed in terms of skeletal bending and stretch modes. And structural implications of the spectra are discussed, particularly for the polymeric materials Ph 3 SnF and Ph 2 SnO.

TL;DR: In this article, it was shown that the symmetric double minimum potential function for cyclobutane-d8 is V(cm−1) = 6.932 × 105χ4 − 3.790 × 104χ2, where χ is one half the distance between the ring diagonals in angstroms.

TL;DR: In this paper, the Urey-Bradley force field was used to estimate the in-plane vibrations of TCNQ and d 4 samples with polarized radiations incident perpendicularly and obliquely upon the sample plane, and the observed bands were experimentally classified into three infrared-active symmetry species on the assumption of the oriented gas model.

TL;DR: In this paper, normal coordinate analyses have been performed on molecules with the amide group using force constants transferred from N-methylacetamides and polyamides, and the agreement between observed and calculated frequencies is good in most cases, and a complete or nearly complete assignment of infrared frequencies has been established.

TL;DR: The vapor and liquid phase infrared spectra (376-4000 cm −1 ) and the liquid phase Raman spectra with polarizations (with polarizations) of cyclohexane and cyclo hexane-d 12 are presented in this article.

TL;DR: In this paper, the infrared spectra of gaseous HCF 3 and DCF 3 were recorded with a resolution between 0.2 and 1.0 cm −1, and the contours of the fundamentals were analyzed in part by classical methods and by contour simulation by a computer.

TL;DR: In this article, the infrared spectra were obtained from powders dispersed in Nujol and the absorption peaks were assigned to the lattice vibrations, predicted on the basis of the factor group.

TL;DR: In this article, the infrared and Raman spectra have been obtained of crystalline films of CH316OCH3, CD316OCD3 and CD316 OCD2H molecules, showing that the CH bond in the plane of the skeleton is slightly stronger than those out of the plane.

TL;DR: In this article, a crystal structure, C 2 h 6 - A 2/a, was proposed based on the splitting of the OH stretching vibration into a broad and a sharp component, which was interpreted in terms of coupling and a tendency towards a tautomerism for some of the HO stretching vibrations of an infinite zigzag hydrogen-bonded chain.

TL;DR: In this paper, the infrared and Raman spectra of fourteen tri-substituted benzenes with the 1, 2, 4 pattern of substitution were measured and a complete interpretation of the spectra was proposed.

TL;DR: The low frequency torsion v7, responsible for the appearance of hot bands, has been investigated in detail and accurate vibrational spacings measured up to the fifth level.

TL;DR: In this article, the infrared spectra of four samples of hydroxyapatites were measured using thin wafers using different pretreatment procedures and at several temperatures, and the spectral characteristics of the stretching vibrations of lattice OH groups and their OD analogues were determined at temperatures from 25 to 600°C.

TL;DR: In this article, the infrared spectra of pyrene and pyrene- d 10 both in solution and in the solid have been measured down to 50 cm −1, complemented by laser-Raman studies of single crystal samples and of solutions in benzene, carbon disulphide and carbon tetrachloride.

TL;DR: In this article, the polarized fluorescence spectra of pyrene pyrene-d10 as guests in biphenyl and fluorene single crystal matrices at about 10°K are presented.

TL;DR: In this article, the normal co-ordinate analysis of the out-of-plane vibrations of eight isotopic molecules has been carried out by using the C3, molecular model.