Determination of the intensities of the absorption bands and the optical constants of layers of materials on metals from IR reflection-absorption spectra

1984 ◽  
Vol 40 (6) ◽  
pp. 696-700
Author(s):  
V. P. Tolstoi ◽  
G. N. Kuznetsova ◽  
I. I. Shaganov
Keyword(s):  
Absorption Spectra ◽  
Optical Constants ◽  
Absorption Bands ◽  
Ir Reflection

Applications of Infrared Methods in the Structural Examination of Synthetic Rubber

1946 ◽  
Vol 19 (4) ◽  
pp. 1113-1123 ◽  
Author(s):  
J. E. Field ◽  
D. E. Woodford ◽  
S. D. Gehman
Keyword(s):  
Absorption Spectra ◽  
Organic Molecules ◽  
Normal Modes ◽  
Structural Variations ◽  
Structural Examination ◽  
Absorption Bands ◽  
Synthetic Rubber ◽  
Modes Of Vibration ◽  
Long Chain

Abstract Infrared absorption spectra have been long recognized as a convenient means for studying the structure of organic molecules. The interpretations of the spectra are based on the energy interactions of the molecule and the radiations which arise from the vibration of the constituent atoms and molecular rotations. For simple or highly symmetrical molecules, the determination of the normal modes of vibration and the calculation of the absorbing frequencies are relatively simple and straightforward. For more complicated organic molecules, this becomes increasingly difficult because with each additional atom, the number of degrees of freedom is increased by three and the determination of the normal modes of vibration becomes practically impossible. However, interpretations can be made to a useful extent through empirical comparisons with the absorption spectra of simpler known structures. The data that have been accumulated by investigators in this field have made it possible to assign rather definite absorption frequencies to some of the chemical linkages and functional groups. These correlations which have appeared in numerous places in the literature are partially reproduced in Table I. Organic compounds generally have strong absorption bands below 1300 cm−1, to which few definite assignments can be made with certainty because the vibrations of many of the atoms of the molecule may be involved rather than a specific part of it. It is clear that such empirical relationships must be relied upon in studying the structural variations of the long chain, complex molecules which occur in butadiene and isoprene polymers and copolymers and other synthetic rubbers. This procedure has been applied to determine the effects of oxidation and of variations in monomers and polymerizing conditions on the structure of synthetic rubber. It is practically certain that physical deficiencies of synthetic rubber are due principally to the structure of the long chain molecules rather than to the chemical nature of the monomers used.

Determination of optical constants and vibrational band intensities of liquids in the infrared using attenuated total reflexion

1967 ◽  
Vol 298 (1453) ◽  
pp. 160-177 ◽  
Keyword(s):  
Refractive Index ◽  
Carbon Tetrachloride ◽  
Working Conditions ◽  
Optical Constants ◽  
Carbon Disulphide ◽  
Absorption Bands ◽  
Total Reflexion ◽  
Solid Liquid Interface ◽  
Solid Liquid

The refractive index, and vibrational absorption band intensities, of some liquids have been determined by a new method involving attenuated total reflexion at a solid liquid interface. The principles of the method have been explained and the factors which determine a choice of optimal working conditions have been discussed. The method has been applied to absorp­tion bands of benzene, carbon tetrachloride, chloroform, bromoform, sym -tetrabromo-ethane, and carbon disulphide. Data have been obtained on the variation of refractive index across the absorption bands, and the computed band intensities have been compared with those obtained previously by other methods.

scholarly journals Bulk Solubility and Speciation of Plutonium(VI) in Phosphate-Containing Solutions

1992 ◽  
Vol 294 ◽  
Author(s):  
H. T. Weger ◽  
S. Okajima ◽  
J. C. Cunnane ◽  
D.T Reed
Keyword(s):  
Absorption Spectra ◽  
Accurate Determination ◽  
Absorption Bands ◽  
Initial Ph ◽  
Colloid Formation

ABSTRACTThe solubility and speciation of Pu(VI) with phosphate is being investigated to determine the ability of phosphate to act as an actinide getter. In the initial studies performed, solubility was approached from oversaturation at an initial pH = 4, 10 and 13.4. Absorption spectra were recorded, the solution filtered, and the filtrate analyzed for Pu content. Absorption spectra were obtained at varying phosphate concentrations, and at pH of 2.7 to 11.9. The effect of complexation on the 833 nm Pu(VI) band was characterized. Evidence for three phosphate complexes was obtained for pH < 10, which have absorption bands at 842, 846 and 849 nm. Evidence for colloid formation was observed, but is not conclusive. The possible presence of colloids prevented an accurate determination of true solubility. A concentration of 10−5 to 10−6M Pu(VI) was measured in solutions at pH ≤ 10 that was filtered with a 50 nm filter. Pu(VI)-phosphate complexes predominated at pH ≤ 11.6. At higher pH, however, only hydrolyzed Pu(VI) was detected. At pH = 12, the concentration of Pu(VI) was as high as 10−4M.

scholarly journals Luminescent determination of residues of trazodon hydrochloride and melatonin after cleaning pharmaceutical equipment

2019 ◽  
pp. 73-81
Author(s):  
O. D. Voitiuk ◽  
A. V. Yegorova ◽  
Yu. V. Scrypynets ◽  
S. N. Kashutskуy ◽  
V. P. Antonovich
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Xenon Lamp ◽  
Excitation Spectra ◽  
Absorption Bands ◽  
Limit Of Quantitation ◽  
Trazodone Hydrochloride

A prerequisite for ensuring the quality of medicines is their production in accordance with the rules of GMP (Good Manufacturing Practice for Medicinal Products), one of the most important requirements of which is equipment cleaning. In many cases, the same equipment is used in the production of various preparations. Therefore, to prevent contamination of each of the following drugs, the previous one, it is very important to carry out an effective equipment cleaning procedure with a mandatory assessment of its purity. The purpose of this study was to develop simple, express, selective methods for luminescent determination of residual quantities of APIs of trazodone hydrochloride (TG) and melatonin (MT) in washes to control the completeness of their removal when cleaning process equipment. The excitation and luminescence spectra were recorded using a Cary Eclipse "Varian" spectrofluorimeter (Australia) with a xenon lamp 150 W. Electronic absorption spectra were recorded on a UV-2401 PC spectrophotometer «Shimadzu» (Japan). The electronic absorption spectra of TG and MT have absorption bands in the UV spectral region. It was established experimentally that the excitation spectra of TG and MT are similar to their absorption spectra (λex = 318 nm (TG) and λem = 274 nm (MT)). The effect on the luminescence intensity of TG and MT of methanol, ethanol, acetonitrile, dimethylformamide, dimethylsulfoxide, propanol (50 v/v) was studied. It is established that the maximum luminescence is observed in water. The methods were validated according to the following parameters: specificity, linearity, accuracy, limit of quantitation. The degree of extraction of trazodone hydrochloride and melatonin from applicators and surfaces of pharmaceutical equipment is more than 90%. The developed methods can be recommended for determining the residual amounts of trazodone hydrochloride and melatonin while monitoring the quality of the cleaning of pharmaceutical equipment.

Dithiolate Mixed with Diimine and it's Metal Effects on Sensors

2014 ◽  
Vol 1021 ◽  
pp. 52-55
Author(s):  
Yong Hui Jia ◽  
Chao Xu
Keyword(s):  
Energy Level ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Spectra ◽  
Electronic Absorption Spectra ◽  
Orbital Energy ◽  
Absorption Bands ◽  
The Relationship ◽  
Orbital Energy Level

Determination of the two Maleinitriledithiolate • phenanthroline-5 ,6-dione Lynn mixed copper (II), zinc (II) complexes MLL' (L=mnty, 1,2 twelve dicyanoethylene-1,2 - thiol ion L '= phen-5, 6-dione, l, 10 - phenanthroline-5 ,6-one o) amine in dimethy-l phthalate (DMF), acetone (Acet.) and chloroform (HCli) electronic absorption spectra corresponding to transitions studied the relationship between the absorption bands in the electronic spectra associated molecular orbital energy level diagram to explore their photographic oxidation characteristics in DMF.

Mechanism of anionic coordination dimerization of isoprene

1981 ◽  
Vol 46 (7) ◽  
pp. 1600-1606 ◽  
Author(s):  
Jan Bartoň ◽  
Karel Volka ◽  
Miroslav Kašpar ◽  
Vlastimil Růžička
Keyword(s):  
Gas Chromatography ◽  
Alkali Metal ◽  
Absorption Spectra ◽  
Visible Radiation ◽  
Absorption Bands ◽  
Absorption Spectrophotometry ◽  
Spectrophotometric Data ◽  
Oligomeric Forms

The mechanism of controlled anionic coordination dimerization of isoprene (i.e. 2-methyl-1,3-butadiene) in the system tetrahydrofuran-isoprene-alkali metal-dialkylamine was investigated by using absorption spectrophotometry in the range of visible radiation and gas chromatography. The effect of the alkali metal (Li, Na, K) and dialkylamine (dicyclohexylamine, N-isopropylcyclohexylamine, N-methylisopropylamine) on the absorption spectra was tested. By comparing chromatographic and spectrophotometric data, the absorption bands in the range of visible radiation were identified with the existence of π-complexes between oligomeric forms of isoprene and alkali metal dialkylamide.

Spectrophotometric study of the reactions of lanthanoids with bromopyrogallol red in the presence of cation active tensides

1982 ◽  
Vol 47 (2) ◽  
pp. 503-508 ◽  
Author(s):  
Irena Němcová ◽  
Pavla Plocková ◽  
Tran Hong Con
Keyword(s):  
Absorption Spectra ◽  
Photometric Determination ◽  
Spectrophotometric Study ◽  
Ternary Complexes ◽  
Optimal Conditions ◽  
Bromopyrogallol Red ◽  
Binary Complexes

The absorption spectra of the binary complexes of lanthanoids with bromopyrogallol red were measured and the formation of ternary complexes with cation active tenside, Septonex, was studied. Optimal conditions were found for the formation of these complexes and the possibility of their use in the photometric determination of lanthanoids was demonstrated on several examples.

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