Spectroscopy solution chemistry

The following case study contains examples of several topics discussed in previous sections, including some aspects of laser technology, laser spectroscopy and laser chemistry. A variety of lasers and laser techniques are applied in a straightforward manner to the problem of ascertaining structural and dynamical information on an excited electronic state of wide chemical interest. This information is obtained rather simply, illustrating the potential of laser techniques in the resolution of problems in solution chemistry. 

An Oven/iew of a Rapidly Expanding Area in Chemistry Exploring the future in chemical analysis research, Ionic Liquids in Chemical Analysis focuses on materials that promise entirely new ways to perform solution chemistry. It provides a broad overview of the applications of ionic liquids in various areas of analytical chemistry, including separation science, spectroscopy, mass spectrometry, and sensors. 

The existence or nonexistence of a residual layer has been studied using surface chemistry techniques such as scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) and solution chemistry calculations. Nickel (1973) calculated the thickness of a residual layer on albite from the mass of dissolved alkalis and alkaline earths released during laboratory weathering. The surface area was also measured, and the thickness of the residual layer was found to range from 0.8 to 8 nm. These results suggested a very thin layer, which would not cause parabolic kinetics. 

LANTHANIDE AND ACTINIDE SOLUTION CHEMISTRY AS STUDIED BY TIME-RESOLVED EMISSION SPECTROSCOPY... 

This volume of the Handbook illustrates the rich variety of topics covered by rare earth science. Three chapters are devoted to the description of solid state compounds skutteru-dites (Chapter 211), rare earth-antimony systems (Chapter 212), and rare earth-manganese perovskites (Chapter 214). Two other reviews deal with solid state properties one contribution includes information on existing thermodynamic data of lanthanide trihalides (Chapter 213) while the other one describes optical properties of rare earth compounds under pressure (Chapter 217). Finally, two chapters focus on solution chemistry. The state of the art in unraveling solution structure of lanthanide-containing coordination compounds by paramagnetic nuclear magnetic resonance is outlined in Chapter 215. The potential of time-resolved, laser-induced emission spectroscopy for the analysis of lanthanide and actinide solutions is presented and critically discussed in Chapter 216. 

Lanthanide and actinide solution chemistry as studied by time-resolved emission spectroscopy 465... 

Aime, S., Botta, M., Fasano, M., etal. (1997) Conformational and coordination equilibria on DOTAcomplexes of lanthanide metal ions in aqueous solution smdied by IH-NMR spectroscopy. Inorganic Chemistry, 36, 2059-2068. 

New techniques such as laser Raman spectrophotometry, NMR spectroscopy and X-ray and neutron diffraction methods, as well as EXAFS and XANES spectroscopy, provide us tools to observe solution phenomena from the microscopic point of view on the bases of structural chemistry and reaction dynamics. Thus, structural and dynamic studies of solutions have been developed as new streams of solution chemistry. 

Altered surfaces have been inferred from solution chemistry measurements (e.g., Chou and Wollast, 1984, 1985) and from spectroscopic measurements of altered surfaces, using such techniques as secondary ion mass spectrometry (for altered layers that are several tens of nm thick (e.g., Schweda et al, 1997), Auger electron spectroscopy (layers <10 nm thick (e.g., Hochella, 1988), XPS (layers <10 nm thick (e.g., Hochella, 1988 Muir et al, 1990), transmission electron microscopy (TEM, e.g., Casey et al, 1989b), Raman spectroscopy (e.g.. Gout et al, 1997), Fourier transform infrared spectroscopy (e.g., Hamilton et al, 2001), in situ high-resolution X-ray reflectivity (Farquhar et al, 1999b Fenter et al, 2003), nuclear magnetic resonance (Tsomaia et al, 2003), and other spectroscopies (e.g., Hellmann et al, 1997). 

Conversion of the as-deposited film into the crystalline state has been carried out by a variety of methods. The most typical approach is a two-step heat treatment process involving separate low-temperature pyrolysis ( 300 to 350°C) and high-temperature ( 550 to 750°C) crystallization anneals. The times and temperatures utilized depend upon precursor chemistry, film composition, and layer thickness. At the laboratory scale, the pyrolysis step is most often carried out by simply placing the film on a hot plate that has been preset to the desired temperature. Nearly always, pyrolysis conditions are chosen based on the thermal decomposition behavior of powders derived from the same solution chemistry. Thermal gravimetric analysis (TGA) is normally employed for these studies, and while this approach seems less than ideal, it has proved reasonably effective. A few investigators have studied organic pyrolysis in thin films by Fourier transform infrared spectroscopy (FTIR) using reflectance techniques. - This approach allows for an in situ determination of film pyrolysis behavior. 

The solid-state and solution chemistry of triethanolamine complexes has been investigated. While the solid-state structure was maintained in organic solvent (38), a different structure was observed in aqueous solution.262 170 NMR spectroscopy was used to demonstrate that the two oxo groups were different and in combination with H and 13C NMR data, defined the structure as (39).262 Speciation studies and a detailed characterization of this class of compounds were important because the ligand is a commonly used buffer in biology and the complexes are model systems for interactions with proteins.61,263 The thermodynamic parameters were determined for several derivatized diethanolamine ligand-vanadium(V) complexes, and represent some of the few vanadium complexes for which such parameters are known.62 The structure of (nitrilotriacetato)dioxovanadate was reinvestigated.2 4... 

To a large extent the discussion will be limited to those complexes that have a discernible solution chemistry (e.g., by spectroscopy). The boundary between metal-oxide lattices and solid-state materials incorporating known and new polyoxometalate structures is becoming less and less well defined. Although this is an interesting and important area, with many potential applications, it is beyond the scope of the present endeavor. 

Gallium C Ga) (I = 312). With the recent progress in Ga solid state NMR, it has become possible to take advantage of the complementary information that can be obtained using NMR and X-ray absorption spectroscopies. Examples of an A1-, Ga-based catalyst are investigated. The solution chemistry and structure of the complex of the triazamacrocychc... 

As discussed in the introduction, during the last decade or two NMR spectroscopy has become the most versatile and powerful technique for studying thallium solution chemistry (39, 40, 54, 161-167). In particular, the potential of this method for studying the aqueous solution chemistry of thallium has been demonstrated in several papers by Glaser et al. (41, 48, 51, 94, 95, 97, 98, 108, 110, 112, 115, 145, 168-174), in which structural, kinetic, and equilibrium problems are studied. In some of these studies, the speciation of the thallium complexes could be elucidated using the individual chemical shifts (and coupling constants) for the studied species 41, 94, 97, 108, 112, 171). 

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