Determination Raman spectroscopic

The most reliable information on the structure of the polymer has been derived from X-ray diffraction and Raman-spectroscopic studies. In a few cases it has been possible to determine in detail the structures of both the monomer and the corresponding polymer. From such measurements and other optical studies the process is considered to be 132 — 133 for a symmetric diacetylene. In polymerizable structures the diacetylene rods are inclined at about 45° to the translation (stack) axis, with the ends of each diacetylene moiety approaching the adjacent triple-bond systems to a distance of s4 A. The polymer is a planar system in extended conformation and having alternate R groups trans to one another. 

T.R.M. De Beer, W.R.G. Baeyens, A. Venneire, D. Broes, J.R Remon, and C. Vervaet, Raman spectroscopic method for the determination of medroxyprogesterone acetate in a pharmaceutical suspension Validation of quantifying abilities, uncertainty assessment and comparison with the high performance liquid chromatography reference method. Anal. Chim. Acta, 589, 192-199 (2007). 

A.N. Batsoulis, N.G. Siatis, A.C. Kimbaris, et al., FT-Raman spectroscopic simultaneous determination of fructose and glucose in honey, J. Agric. Food Chem., 53, 207-210 (2005). 

Uchida, T. Hirano, T. Ebinuma, T. Narita, H. Gohara, K. Mae, S. Matsumoto, S. (1999a). Raman spectroscopic determination of hydration number of methane hydrates AIChEJ., 45 (12), 2641-2645. 

Resonance Raman Spectroscopy. A review of the interpretation of resonance Raman spectra of biological molecules includes a consideration of carotenoids and retinal derivatives. Another review of resonance Raman studies of visual pigments deals extensively with retinals. Excitation profiles of the coherent anti-Stokes resonance Raman spectrum of j8-carotene have been presented. Resonance Raman spectroscopic methods have been used for the detection of very low concentrations of carotenoids in blood plasma and for the determination of carotenoid concentrations in marine phytoplankton, either in situ or in acetone extracts. ... 

Raman Spectroscopic Determination of Heats of Vaporization of Pure Liquids 44... 

Information about the structure of gas molecules haB been obtained by several methods. Spectroscopic studies in the infrared, visible, and ultraviolet regions have provided much information about the simplest molecules, especially diatomic molecules, and a few polyatomic molecules. Microwave spectroscopy and molecular-beam studies have yielded very accurate interatomic distances and other structural information about many molecules, including some of moderate complexity. Molecular properties determined by spectroscopic methods are given in the two books by G. Herzberg, Spectra of Diatomic Molecules, 1950. and Infrared and Raman Spectra, 1945, Van Nostrand Co., New York. The information obtained about molecules by microwave spectroscopy is summarised by C. H. Townes and A. L. Schawlow in their book Microwave Spectroscopy of Gases, McGraw-Hill Book Co., New York, 1955. 

We have applied a laser Raman spectroscopic (25) and ion chromatographic (26) techniques to the determination of N-S compounds in reaction mixtures. Both techniques require only a small amount of... 

Our results on the spectral substructure of the OH absorption are consistent with the bandshape in the conventional IR spectrum of HDO. For a quantitative description of the latter an additional weaker component at 3270 cm-1 is required below 300 K that shows up also in the transient spectrum in the same temperature range, denoted with I . This component is located at a frequency determined for a special ice conformation from Raman spectroscopic investigations (112). A further contribution to the overall OH-absorption band of HDO is noticed at 3260 cm-1 the latter is believed not to represent OH-stretching transitions and was recently assigned to a combination tone (89). Increase of temperature reduces significantly the contribution of components I and II, while species III dominates the conventional absorption band above 290 K. 

As 1 is a nonpolar symmetric top with symmetry, it should have no pure rotational spectrum, but it acquires a small dipole moment by partial isotopic substitution or through centrifugal distortion. In recent analyses of gas-phase data, rotational constants from earlier IR and Raman spectroscopic studies, and those for cyclopropane-1,1- /2 and for an excited state of the v, C—C stretching vibration were utilized Anharmonicity constants for the C—C and C—H bonds were determined in both works. It is the parameters, then from the equilibrium structure, that can be derived and compared from both the ED and the MW data by appropriate vibrational corrections. Variations due to different representations of molecular geometry are of the same magnitude as stated uncertainties. The parameters from experiment agree satisfactorily with the results of high-level theoretical calculations (Table 1). 

A few IR and Raman spectroscopic investigations on Zintl ions have been reported. The assignment of the observed frequencies is determined by normal coordinate analysis and force constants for such compounds as CS6M2PU4 (M = Al, Ga Pn = P, As), " CseMPns (M = In, Al Pn = As, Sb), and MsPnii (M = Na, K, Rb, Cs Pn = P, As). Some properties of the homoatomic nine-atom Zintl ions of group 14 (Si Pb) have been reviewed. ... 

X-ray and time-of-flight (TOF) neutron diffraction and Raman spectroscopic measurements have been carried out at 25°C on concentrated aqueous sulfuric acid solutions, (H2S04),(H20),, x = 0, 0.25, 0.5, 0.75 and 0.86, in order to investigate the hydrogen-bonded intermolecular stmcture in the solutions. The intramolecular parameters for regular tetrahedral SO4 unit were determined from the least squares fit to observed X-ray and neutron interference terms in the range of Q S 8. The nearest neighbor... 

The most extensive research results concern the hydride electrolyte system 2 [13-16, 68, 78, 82, 92, 93, 102, 209]. With the help of Raman spectroscopic measurements, the chemical constituents of the electrolyte were determined and the electrode reactions examined with chronoamperometric methods [82]. The catalytic role of hydride and the role of neutral and ionic aluminum components were thus detected. The dependence of the polarization parameters on the electrolyte composition shows a marked maximum from which the bath composition with the highest current distribution can be determined. The influence of the temperature and the composition on the electrode process kinetics was studied by Badawy et al. [13-16]. The results of Eckert et al. [68] show a dependence of the activation energy on the electrolyte composition of the hydride baths. The first electrochemical investigation results with respect to type 3 aluminum alkyl electrolyte were obtained by Kautek et al. [100, 101] and Tabataba-Vakili [186, 187, 133]. 

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