Nuclear magnetic resonance spectroscopy selective oxidation

It is clear from the above considerations that the most often used and widely reported XRD analysis becomes insufficient to provide detailed information about amorphous phases. The benefits of in-depth studies of mechanochemical reaction mechanisms by selection of appropriate analytical tools, able to provide data on a short-range (local) structural scale, such as nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) spectroscopy, infrared spectroscopy (IR), Raman spectroscopy, etc., were demonstrated by the pioneering work of Senna, Watanabe and coworkers (Watanabe et al., 19%, 1997 Senna, 1997). In those cases, the synthesis of selected complex oxide systems have been studied from starting mixtures comprising typacaUy hydroxide and oxide compounds extensive data on these studies can be foimd in Avvakumov et al. (2001). 

Spectroscopic characterization is also important in the study of oxide minerals. Among the many methods (Sections 7.3 through 7.7), it is important to mention X-ray fluorescence (XRF, Section 7.3.3), which allows a rapid elemental analysis of mineral samples. Electron microscopy allows observation of clay fraction particles shape and, coupled to X-ray spectroscopy, also elemental analysis (Section 7.5). Infrared spectroscopy (Section 7.4.3) is also frequently employed here, difference spectra combined with selective extraction procedures (Hass and Fine 2010) can be used to identify and study minor components (Golden, Dixon, and Kanehiro 1993). Nuclear magnetic resonance (NMR, Section 7.4.4) is in some cases useful (with uneven spin nuclei), for example, to distinguish octahedral and tetrahedral A1 centers (Bertsch and Parker 1996). 

Selected physical properties such as spectroscopy and magnetic chemistry reveal useful data on the general skeletal arrangement, bond strength, energy, and valency of metal Tu-complexes. In this chapter some of the details of infrared spectroscopy (IR), nuclear magnetic resonance (NMR), mass spectra, Mossbauer spectroscopy, magnetic susceptibility, and oxidation state are discussed in terms of the characterizations of metal 7i-complexes. 

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