Showing papers in "Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy in 1989"

TL;DR: In this paper, the theoretical factors governing the relationship between atomic absorption and atomic concentration are examined and the experimental problems involved in recording atomic absorption spectra are discussed, and it is shown that such spectra provide a promising method of chemical analysis with vital advantages over emission methods, particularly from the viewpoint of absolute analysis.

TL;DR: In this paper, the interface between a dielectric of high refractive index and the sample is taken as the reflecting surface, and a reflection spectrum of high contrast and intensity is obtained, which strongly resembles a transmission spectrum.

TL;DR: In this paper, the i.r. spectra of cytosine and its d3-deuterated derivative isolated in Ar and Ne matrices are reported, and the amino-hydroxy and amino-oxo tautomeric forms dominate in matrices.

TL;DR: In this article, the ir and Raman spectra of monovalent bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) based charge transfer salts were investigated.

TL;DR: In this paper, the authors used a perturbation method programmed for the IBM 7090, which adjusts force constants for any number of molecules simultaneously with an average error of 0·25 per cent.

TL;DR: In this article, the vibrational spectra of chain metaborates (LiBO2, CaBO2O4, SBSO4 and SrB2O 4) containing only condensed BO3 groups has been investigated by group theoretical methods and isotopic substitutions.

TL;DR: In this paper, a vibrational Hamiltonian is proposed for regions containing overtones or combinations of the three normal modes, excluding the symmetric inversion motion, which is capable of modeling the normal mode to local mode transition observed in the spectrum as well as the observed band origins, rotational constants and intensifies.

TL;DR: The model can be used to separate effects due to fluorescence and absorption, and to deconvolute contributions from individual chromophores, extracting information about their relative concentrations, and may potentially prove to be useful in determining the chemical composition of atherosclerotic lesions in vivo.

TL;DR: The surface enhanced resonance Raman spectra (SERRS) are identical to the RRS spectra with an enhancement factor of about 500, consistent with a C 4 v molecular symmetry as discussed by the authors.

TL;DR: In this article, the complete harmonic force field of benzonitrile has been determined by ab initio Hartree-Fock calculations using a 4-21 Gaussian basis set.

TL;DR: In this article, laser induced fluorescence from normal human aorta was studied with u.v. excitations of 305 to 310 nm, observing emission from 320 to 500 nm, suggesting that at least two fluorophores are being observed.

TL;DR: In this article, a method for complete vaporization of a substance in a graphite crucible is proposed, which eliminates the effect of the composition of the sample on the analytical results.

TL;DR: In this article, the interface between a dielectric of high refractive index and the sample is taken as the reflecting surface, and a reflection spectrum of high contrast and intensity is obtained, which strongly resembles a transmission spectrum.

TL;DR: In this paper, the nuclear spin-spin coupling constants J (C,H) and J(C,D) have been measured over the temperature range 200-370 K for the methane isotopomers 13 CH 4, 13 CH 3 D, 13 CHD 3 and 13 CD 4.

TL;DR: In this paper, the spectral properties of poly(p-phenylene sulfide) and some of its oligomers have been investigated and a tentative symmetry-based assignment for the observed modes is given.

TL;DR: The SERS spectra of carbonate, hydrocarbonate, and several substituted acetic acids absorbed on silver hydrosols are recorded in this paper, revealing that the acids are initially adsorbed in a single bonding state through the carboxyl group.

TL;DR: In this article, a cosine-based potential function governing internal rotation of the CHO top has been determined and the potential coefficients have values of V 1 = 173 ± 2, V 2 = 3112 ± 20, V 3 = 113 ± 2 and V 4 = −198 ± 6 cm −1.

TL;DR: In this article, the authors define the Nachweisgrenze durch eine Messvorschrift, i.e., the Schwarzungsunterschied, with dem die Linie sich uber den Untergrund erhebt, das 3 · √2 fache der mittleren Schwarzungsschwankung sein.

TL;DR: In this article, the absorption spectra in different pH solutions and in organic solvents with different polarity were measured, and the forms of these dyes in various media were reasonably assigned.

TL;DR: In this paper, the solid charge transfer complexes formed in the reaction of iodine with the polycyclic amines 1,4,8,12-tetraazacyclopentadecane (TACPD) and meso -5,7, 7, 12, 14, 14-hexamethyl-1,4.8, 11-Tetrasacyclotetrades (HMTACTD) have been investigated by resonance Raman and far ir spectroscopy.

TL;DR: In this article, two regions in the i.r. spectra of uracils are analyzed: (a) the NH stretching region in crystals, and (b) the CO bending region in matrix-isolated monomers.

TL;DR: In this paper, the rotational and vibrational constants of the D 1 Δ state have been determined using a single mass-reduced fit for all three isotopomers of carbon monoxide.

TL;DR: The ground state and protonated state (quaternized salt) vibrational spectra (200-1800 cm −1 ) of the title amines are reported for various ring and/or methyl deuterated derivatives.

TL;DR: In this article, the intensity of the Raman spectra of liquid ethanol and ethanol-d1 at Δ ν =270 cm−1 was used to determine the enthalpy of hydrogen-bond formation between nonbonded and hydrogen bonded alcohol species over the temperature range 156 to 347 K.

TL;DR: In this paper, the X-ray structures of 2,4,6-trinitrotoluene and α-d3 have been determined at 130 K. The molecular structure and vibrational spectra are calculated by the MNDO-PM3 method, and are in agreement with experimental results.

TL;DR: In this article, the shape and aggregation state of the microcrystals explain the differences observed in the i.r. powder spectra of BaTiO 3, SrTiO3 and LiNbO 3.

TL;DR: In this article, the Stokes-Mueller formalism was applied to the case of right angle scattering of chiral molecules randomly oriented in an optically isotropic phase, and orientations of the polarization analyzer in the scattered beam at the "magic angle" of ∼ ±35.26° to the vertical have been identified to isolate the pure magnetic dipole contribution to the ROA intensity.

TL;DR: Pre-mixed flames with temperatures of about 2900°C were used in this paper for atomic absorption spectroscopy of 25 metals, including calcium, strontium, barium and molybdenum.