The Use of Raman Spectroscopy and Methods of Quantum Chemistry for Assessing the Relative Concentration of Triglycerides of Oleic and Linoleic Acids in a Mixture of Olive Oil and Sunflower Seed Oil

The Raman spectra of five samples of sunflower seed oil and five samples of cold-pressed olive oil of various brands are recorded in the range of 500–2000 cm^–1. Within the framework of the B3LYP/6-31G(d)/6-31G(d,p)/6-31+G(d,p)/6-311G(d)/6-311G(d, p)/6-311+G(d,p) methods, the structural models of eight fatty acids (oleic, linoleic, palmitic, stearic, α-linolenic, arachidonic, eicosapentaenoic, and docosahexaenoic) are constructed, and also within the framework of the B3LYP/6-31G(d) method, the structural models of triglycerides of the first four of the above acids are obtained. The vibrational wavenumbers and intensities in the IR and Raman spectra are calculated. The Raman spectra of olive oil and sunflower seed oil were simulated by using the supermolecular approach. We investigated the dependence of the relative intensity of the vibrational bands ν_exp = 1660 and 1445 cm^–1 on the concentration of triglycerides in oils of oleic and linoleic acids and the dependence of the intensity of these bands on the degree of saturation of fatty acids. Experimental and empirical dependences are constructed to estimate the relative concentration of triglycerides of oleic and linoleic acids in a mixture of olive oil and sunflower seed oil. The applicability of the density functional theory together with the vibrational spectroscopy for the identification of mixtures of vegetable oils is discussed.     

Bandgap-width correction for luminophores CaMoO<Subscript>4</Subscript> and CaWO<Subscript>4</Subscript>

Submicron-powder luminophores CaMoO₄ and CaWO₄ obtained via solid-phase reactions have been studied using diffuse-reflection (DR) spectroscopy and photoluminescence (PL) spectroscopy. It is found that the diffuse-reflection spectrum in the range of a fundamental absorption edge of <300 nm is distorted by PL overlapping, so that subsequent calculations of optical band gap E _g of luminophores CaMoO₄ and CaWO₄ result in an overestimation of this value. An algorithm for the correct processing of diffuse-reflection spectra is described. It is based on a subtraction of the photoluminescence spectrum in the range of fundamental absorption. The correct E _g values and energy values for the defect levels in the bandgap of CaWO₄ and CaMoO₄ are determined to amount to 4.78, 4.83, and 4.86 ± 0.01 eV and 3.97, 4.07, 4.16 ± 0.01 eV, respectively.     

Iron-substituted tricalcium phosphate ceramics

Porous iron-substituted tricalcium phosphate (FeTCP) ceramics with a Fe content of 0.49 and 1.09% has been developed. The hydrostatically estimated ceramics porosity is 40–45%. The solubility of ceramics in an isotonic solution has been studied. The solubility rate of FeTCP ceramics is slightly higher as compared with iron-free ceramics. Based on the results of in vitro tests of FeTCP ceramics on cultured fibroblasts, these materials are believed to be biocompatible. The developed materials can be recommended for use in medicine in the treatment of diseases associated with bone lesions.     

Directional Synthesis of Hybrid Polymers from 2- and 4-Vinylpyridines

Formation of hybrid three-dimensional structures by treatment of copolymers of 2- and 4-vinylpyridine with butyllithium, followed by grafting of tert-butyl acrylate molecules, was studied by mass-spectrometric thermal analysis and ¹³C NMR spectroscopy.     

Vinylidene complexes of transition metals : III. Derivatives of cyclopentadienyltricarbonyl rhenium with phenylvinylidene ligands. Crystal and molecular structure of Cp(CO)2Re[CC(Ph)C(Ph)CH2]Re(CO)2Cp

The novel complexes CpRe(CCHPh)(CO)₂ and Cp₂Re₂(μ-CCHPh)(CO)₄ containing a terminal and a bridging phenylvinylidene ligand respectively and the binuclear complex Cp(CO)₂Re[CC(Ph)C(Ph)CH₂]Re(CO)₂Cp were obtained in the reaction of CpRe(CO)₃ with PhCCH.According to an X-ray study of the latter complex the unusual bridging ligand is η¹-bonded to one Re atom and η²-bonded to the other.     

IonosphericE region andE — F1 valley as indicators of solar radiant fluxes in the 10–30 nm wavelength region

To estimate the solar radiant flux by an indirect route in the spectrum region from 10 to 30 nm, which is difficult for direct measurement, we propose to use the data on the electron density in the E region maximum and E-F1 valley. Taken from empirical models, the data on these parameters were correlated with theoretical calculations. It is shown that at wavelengths of from 10 to 30 nm the solar radiant flux is about 2.5 times greater than that measured from the AE- E satellite. The results are used to correct the model spectra of extreme UV radiation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 39, No. 10, pp. 1249–1253, October, 1996.The authors are grateful to E. O. Perekalina for giving them software for photochemical calculations of theE region.This work was supported in part by the Russian Foundation for Fundamental Research under Project No. 95-05-15420a.     

N-[3-nitro(amino)coumarin-4-yl]anthranilic acid amides. Synthesis of 6,7,8,13-tetrahydro[1]benzopyrano[4,3-b][1,4] benzodiazepine-6,8-dione

The reaction of 3-nitro-4-chlorocoumarin with anthranilic acid was used to synthesize N-(3-nitro-4-coumarinyl)-anthranilic acid, from which, through the acid chloride, we obtained a number of amides, which were reduced to N-(3-amino-4-coumarinyl)anthranilic acid amides The latter are cyclized under the influence of hydrochloric acid to 6,7,8,13-tetrahydro[1]benzopyrano-[4,3-b][1, 4]benzodiazepine-6,8-dione, which was also obtained from N-(3-amino-4-coumarinyl)anthranilic acid by its thermolysis or treatment with hydrochloric acid.See [1] for our preliminary communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1208–1212, September, 1989.     

Proton NMR study of α-MnH0.06

Proton nuclear magnetic resonance (NMR) spectra and spin-lattice relaxation rates for the solid solution α-MnH_0.06 have been measured over the temperature range 11-297 K and the resonance frequency range 20-90 MHz. A considerable shift and broadening of the proton NMR line and a sharp peak of the spin-lattice relaxation rate are observed near 130 K. These effects are attributed to the onset of antiferromagnetic ordering below the Néel temperature T_N≈130 K. The proton NMR line does not disappear in the antiferromagnetic phase; this suggests a small magnitude of the local magnetic fields at H-sites in α-MnH_0.06. The spin-lattice relaxation rate in the paramagnetic phase is dominated by the effects of spin fluctuations.     

Synthesis of ω-(2-oxocyclododecyl)alkanoic acids by alkylation of cyclododecanone with ω-haloalkanoic esters under conditions of phase-transfer catalysis

(-(2-Oxocyclododecyl)alkanoic acids have been obtained by alkylation of cyclododecanone with alkyl 3-bromopropionate, 5-iodopentanoate, and 11 -bromoundecanoate under conditions of phase-transfer catalysis.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2521–2523, December, 1995.