Raman spectroscopy aqueous solutions, study

Studies of metal ion coordination with anion ligands in mixed organic/aqueous solvent systems have provided novel information about the metal ion coordination numbers and mechanism of crystallization processes from Raman spectroscopy. Also, thermodynamic parameters such as enthalpy of band formation or breakage have been evaluated from Raman spectra of solution studied over a range of temperatures. 

The varying actual orientation of molecules adsorbed at an aqueous solution-CCU interface with decreasing A has been followed by resonance Raman spectroscopy using polarized light [130]. The effect of pressure has been studied for fatty alcohols at the water-hexane [131] and water-paraffin oil [132] interfaces. 

Transient Raman spectroscopy was also used to study charge transfer reactions across aqueous solution interfaces. One optical pulse above the band gap creates... 

IR and Raman spectroscopy have been commonly used and, for example, the effects of pressure on the Raman spectrum of a zinc compound with a N2C12 coordination sphere around the metal, have been investigated.28 IR spectroscopy has been utilized in studies of the hydration of zinc in aqueous solution and in the hydrated perchlorate salt.29 Gas phase chemistry of zinc complexes has been studied with some gas phase electron diffraction structures including amide and dithiocarbamate compounds.30-32... 

There are also several papers describing adsorption of quinoline. Sawamoto [143] have studied adsorption and reorientation of quinoline molecules at Hg electrodes by recording differential capacity-potential and differential capacity-time plots using the flow-injection method. Adsorption of quinoline was found reversible at any potential, with the possibility of reorientation of the molecules at the interface. Ozeld etal. [144] have studied adsorption, condensation, orientation, and reduction of quinoline molecules at pure Hg electrode from neutral and alkaline solutions, applying electrochemistry and Raman microprobe spectroscopy. The adsorbed quinoline molecules changed their orientation from the flat at —0.1 V > E > —0.3 V, to the upright at < —0.5 V. At potentials —0.3 V > > —0.5 V, both orientations were observed. Later, Ozeld et al. [145] have extended the studies on reorientation of quinolinium ions at the Hglacidic aqueous solution interface. For these conditions, the specific adsorption of quinoline was not observed. 

The infrared (IR) spectra of 1,10-phenanthroline, its hydrate and perchlorate in the region 600-2000 cm-1 have been obtained, and the principal features of the spectra interpreted.66 Further studies on the IR spectra of 1,10-phenanthroline,67-69 substituted 1,10-phenanthrolines,70,71 and 1,7-phenanthroline67 have also been reported. The IR spectrum of 4,7-phenanthroline in the region 650-900 cm-1 has been analyzed, and the C—H out-of-plane deformation frequencies were compared with those of phenanthrene and benzo[/]quinoline.72 The IR spectra of salts of 1,10-phenanthroline have been taken, and the NH vibrations determined.28,73 Infrared spectroscopy has been used to detect water associated with 1,10-phenanthroline and some of its derivatives on extraction into nitromethane from aqueous solution.74 The Raman spectrum of 1,10-phenanthroline has been compared with its IR spectrum.75 Recently, the Raman and IR spectra of all ten isomeric phenanthrolines were measured in solution and solid states, and the spectra were fully discussed.76... 

The composition of aqueous solutions of D-arahino-2-hexulose (d-fructose) has also been studied by laser-Raman spectroscopy.45 (The composition of solutions of D-fructose appears to have been determined by more methods, and more often, than that of any other sugar.20)... 

One further attraction of the Raman technique for vibrational studies is that water of bonded OH groups does not cause obscuration of the spectrum but, of course, Raman spectroscopy is useless for studies on water in polymers. At Southampton, excellent spectra of numerous solid mono-, di-, and trisaccharides have been recorded as well as aqueous solutions of some species. It is quite probable that Raman spectra of biologically interesting polymers may be produced shortly8. The ability to examine samples in aqueous regimes obviously has its attractions to the biochemist 1... 

The coordination of Cd2+ by nitrite ion in aqueous solution has been studied by Raman spectroscopy,644 and cumulative formation constants have been derived (j81-j84 = 61.6, 993, 2390, 1899). Bidentate O chelation is postulated, except in the third and fourth complexes where unidentate nitrite is also present. This is in contrast to Zn, which forms Zn(N02)2 as its highest complex in aqueous solution. 

The careful study of Zn-Cl stretching frequencies by Raman spectroscopy in aqueous solutions of zinc chloride in hydrochloric acid solutions has allowed the quantitative study of [ZnCLj2- formation.977... 

Raman spectroscopy is a good technique for studying species in aqueous solution. Liquid water has a relatively weak Raman effect, and solutes can readily be studied. In contrast, water is a very strong absorber of IR radiation, and the broad bands blot out most of the region. Quantitative measurements of equilibria in aqueous solution can be carried out by means of Raman spectroscopy. 

In this report we describe novel pressure tuning vibrational spectroscopic techniques that can be used to study aqueous surfactant solutions and discuss in some detail two examples of such studies with micellar solutions of anionic surfactants, one using Fourier transform infrared (FT-IR) and another using Raman spectroscopy. 

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