Showing papers in "Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy in 1985"

TL;DR: In this paper, the Pariser-Parr-Pople method was used to calculate the resonance Raman spectra of Orange II and Para Red under both neutral and basic conditions, and the changes in the spectra on deuteration and correlation with the calculated bond orders enabled a vibrational assignment to be made.

TL;DR: A review of the results obtained for chlorophyll a and its analogues in frozen solutions at low temperatures by means of site selection and hole-burning techniques is given in this article, where the main attention is paid to the principles of the methods, the analysis of the vibronic structure of the fluorescence and excitation spectra, the interpretation of the processes responsible for the hole burning and the determination of the relaxation times.

TL;DR: In this paper, a comparison with solid state 13 C NMR studies and elemental analysis of polyacrylonitrile is made for the degraded material based on comparison with the degraded materials' spectral properties.

TL;DR: In this paper, a least square adjustment of the force constants of the 34 fundamental frequencies of the molecule expected in the 200-1800 cm−1 range have been observed with their isotope shifts.

TL;DR: In this paper, a modified valence force field is determined; the average error between the 736 observed and calculated wavenumbers is 6.59 cm −1 or 0.90%.

TL;DR: In this paper, three structural models have been considered: (i) one 2D independent V 2 O 5 layer, (ii) the same 2D layer as (iii) in which all the vanadium atoms are coordinated by water molecules, and (iv) a 2D fibril (infinite in one dimension and made of five V O 5 units in the other).

TL;DR: In this paper, the effects of N 3 -deuteration and methylation at N 1 and N 3, on the spectrum of the parent uracil molecule are investigated in detail.

TL;DR: In this article, the relative intensity of the i.r. and Raman bands, the frequency shifting among the halate monohydrates, the single crystal Raman spectra and the spectra of matrix isolated ClO −3 and BrO − 3 ions (site symmetry C 1 ) show three XO stretching bands (one v 1 and two v 3 ).

TL;DR: The asymmetric shape or splitting of the XH or ν(XD) bands of OH(OD), NH, SH and CH proton donors hydrogen bonded to the carbonyl group of ketones, aldehydes, esters, amides, ureas and carbamates have been explained by the existence of two stereoisomeric complexes.

TL;DR: In this paper, the effect of intermolecular interactions on the normal modes of vibration of 1-methyluracil (1-MeU) molecules in different solid phases and at different temperatures (10, 300 K) was investigated.

TL;DR: In this article, molecular vibrational analyses of two biochemically important molecules, namely pyridine-2-thione and pyrimidine 2-thion, have been made for all the fundamentals employing the Urey-Bradley potential function supplemented with valence force function for the out-of-plane vibrations.

TL;DR: In this article, the copper(II) complexes of N -phenyl-2-[1-(2-pyridinyl)ethylidene]hydrazinecarbothioamide (LH) have been synthesized and characterized by elemental analysis, magnetic measurements, i.r.

TL;DR: In this paper, the fundamental frequencies of 6-amino uracil (6AU), 6amino-2-thio URACIL (6A2TU) and their N -deuterated derivatives have been assigned on the basis of normal coordinate calculations carried out using a Urey-Bradley potential function supplemented with valence type constants for the out-of-plane modes of the planar skeleton.

TL;DR: In this article, the vibrational frequencies of the hydrogen (and deuterium) maleate (HM) ion in C 2υ symmetry were computed under the ab initio scheme (4-31 basis set).

TL;DR: In this article, the regularized least squares method and the Davidon-Fenton-Powell method were used in combination to determine 28 Cu porphin force constants, which were tested through calculating normal vibrations of the Cu 1,3,5,7-tetramethylporphin molecule to show their agreement with experiment.

TL;DR: In this paper, infrared and Raman spectra have been obtained from 11 isotopomers of cis and trans but-2-enes in various phases (c - and t -CH 3 CHCHCH 3, CH 3 CHCDCH 3, CD3 CHCDCD 3, CD 3 CDCDCD3, CD3 CDCDCH3 ; c - CH 3 CD-CDCH-3 ).

TL;DR: In this article, the infrared and Raman spectra of polycrystalline dawsonite type compounds MAl(OH) 2 CO 3 (M = Na, K, NH 4 ) have been obtained between 4000 and 40 cm −1.

TL;DR: In this article, the low temperature absorption spectrum of tris(η 5 -cyclopentadienyl)-praseodymium(III) dissolved in a 2-methyltetrahydrofuran glass has been measured.

TL;DR: In this paper, it has been shown that the accurate study of i.r. intensities allows one to derive a quantitative description of the charge distribution (static and dynamic) in small molecules, from this background knowledge it is possible to propose simple rules which allow one to gain similar information on large organic molecules even when the available data on intensity are very limited.

TL;DR: By isotopic substitution in the salt [Fe3O(OOCCH3)6(py)3] [FeCl4], the in-plane asymmetric vibration and out-of-plane vibration were identified at 600 cm−1 and 300 cm− 1, respectively.

TL;DR: In this article, the surface enhanced Raman effect by silver island films was used to study the PbPc compound that gives rise to a strong fluorescence under normal laser excitation.

TL;DR: The polarized Raman spectrum of p -trifluoromethyl aniline was recorded on a Jobin Yvon Ramanor HG.2S spectrometer equipped with an argon-ion laser.

TL;DR: In this article, the transmission and reflection and Raman spectra of potassium hydrogen maleate (KHM) single crystals were measured by means of the four parameter dielectric function, and the analysis of the reflection spectra showed the B 1 u modes in the region below 1100 cm −1, where the hydrogen bond stretchings are located, are strongly anharmonic.

TL;DR: In this paper, the i.r. and Raman spectra of the phases of InVO 4 and TlVO 4 were analyzed with the aid of a site symmetry analysis and by comparison with the results obtained for other orthovanadates.

TL;DR: In this paper, the wavenumbers of chlorophyll a S0-S1 as well as Soret band maxima for 37 solvents were correlated with non-specific [polarity (e − 1/e + 2), polarizability (n2 − 1 /n2 + 2)] and specific (electrophilicity, nucleophilicity and steric hindrance to solvation) solute-solvent interaction parameters using multi-parameter linear regression analysis.

TL;DR: In this paper, an explanation for the high frequency of the NN stretching absorption in the spectra of coordinated N 2 H + 5 ion is offered, but as no strong hydrogen bonds were observed, their high position, comparable with fluorides, seems to be caused by some other effects.

TL;DR: In this paper, the resonance Ramaman spectra of Fe(Ag) → MS4 electron delocalization have been measured using different laser lines and the results have been discussed in the light of the nitrogenase problem.

TL;DR: In this article, the authors present a survey of the state of the art in the characterization and analysis of copolymers by pyrolysis with subsequent analysis of the pyrolysate.

TL;DR: In this article, the i.r. spectra of the title compounds have been recorded in the region 3500-3150 cm −1 in CH 2 Cl 2 and CH 2 CL 2 /DMSO solutions, and the influence of the exo-chalcogen atoms on these frequencies has been discussed.

TL;DR: The majority of the complexes were found to be oxygen co-ordinated with the exception of NiCl 2 (nmf) 4, NiCl(nmf), NiCl2 (dmf) 2 and CuCl(dmf), which showed signs of both oxygen and nitrogen co-coordination as mentioned in this paper.