Spectra from oxidizers

Fig. 3.8. SSIMS spectra from oxide (A) positive SSIMS spectrum, 3 s ...

Figure 9,5. Spectra demonstrate three independem methods to determine ceria oxidation state. Spectra from oxidized (black) and highly reduced (gray) ceria are shown.

Figure S4. SSIMS spectra from oxide nims formed on aluminum after anodization treatment in phosphoric acid for 3 or 5 s 1186) A) Positive SSIMS spectrum, 3 s B) Positive SSIMS spectnim. 5 s C) Negative SSIMS spectrum. 3 s D) Negative SSIMS spectrum. 5 s...

Figure 3-12. O MAS NMR spectra from oxide gels heated to various temperatures for (a) Zr02 where the two resonances from the monoclinic form are replaced by a resonance characteristic of the tetragonal phase at the crystallization temperature reproduced from Chadwick etal (2001) with permission of the American Chemical Society, and (b) Ti02 where the Cni4 resonance is gradually lost as the sample is heated, reproduced from Bastow et al (1993) with permission of the Royal Society of Chemistry.

Figure 10, C l.v XPS spectrum from an untreated pitch-based carbon fiber (a) compared with spectra from oxidized fibers (d) at 2.0 V, (e) at 2.. 5 V. and (f) at. TO V. and from solid hydroquinionc (b) and solid benzoquinone (c). (From Ref. 2. i.)...

SIMS has not been much used as a tool for studying corrosion. The main reason for this seems to be that SIMS spectra and depth profiles are frequently difficult to interpret in terms of clearly defined diffusion or deposition mechanisms. Spectra from oxides contain a complex (and frequently overlapping) series of molecular ion masses secondary-ion depth profiles are complicated in the oxide and interface region by matrix-effected changes in ion yield... 

The interpretation of ELS spectra from oxides is considerably more complex. In oxides the electrons are tightly bound, and there are no free electrons in metal-... 

Figure 7. Oxidative polyamide fluorescence emission spectrum from oxidized soy lecithin liposomes (excitation wavelength, 360 nm).

Fig. 2.15. Comparison of the Cu 2p3 2 and satellite XPS spectra from several copper compounds with the spectrum from the superconducting oxide YBajCujOj [2.76],...

Attempts to prepare 6-hydroxybenzofuroxan by demethylation of 5-methoxybenzofuroxan, by pyrolysis of 4-azido-3-nitrophenol, and by hypochlorite oxidation of 4-amino-3-nitrophenoD failed. This rather unstable compound was finally prepared by hydrolysis of 5-acetoxybenzofuroxan its tautomeric possibilities are numerous, but from the similarity of its ultraviolet spectrum to that of 5-methoxybenzofuroxan it was considered to be largely in the hydroxy form. It is a fairly strong acid, of pK 6.76 (cf. 5-hydroxybenzo-furazan, pK 7.28). 7-Hydroxy-4,6-dinitrobenzofuroxan has been reported as arising from oxidation and nitration of dinitrosoresorcinol monooxime (tetraoxocyclohexene trioxime). ... 

For example, Fig. 9.40 shows the NIS spectra of the oxidized and reduced FeS4 centers of a rubredoxin mutant from Pyrococcus abyssi obtained at 25 K together with DFT simulations using different models for the Fe-S center [103]. The spectrum from the oxidized protein Fe S4 (S = 5/2) reveals broad bands around 15-25 meV (121-202 cm ) and 42-48 meV (339-387 cm ) consistent with the results on rubredoxin from Pyrococcus furiosus [104]. 

Fig. 32 a O Is spectrum for oxidized HffSio.sAso.sfAs at a take-off angle of 15°. b Plot of O Is peak intensities vs. take-off angle for different surface components (excluding adsorbed H2O). Reprinted with permission from [113], Copyright Wiley... 

Several types of reactions involving solids with gases or liquids occur at the interface between the two phases. The most important reaction of this type is corrosion. Efforts to control or eliminate corrosion involve research that spans the spectrum from the coatings industry to the synthesis and production of corrosion-resistant materials. The economic ramifications of corrosion are enormous. Although there are numerous types of reactions that can be represented as taking place at an interface, the oxidation of a metal will be described. Figure 8.6 represents the oxidation of a metal. 

Fig. 9.20. Cf-PD mass spectrum of oxidized insulin. Reproduced from Ref. [156] by permission. John Wiley and Sons, 1994.

Methylbenzenes lose a proton from a methyl group to form a benzyl radical. In aqueous M-percbloric acid this reaction is fast with a rate constant in the range 10 lO s and the process is not reversible [24]. The process becomes slower as the number of methyl substituents increases, Hexaethylbenzene radical cation is relatively stable. When the benzyl radical is formed, further reactions lead to the development of a complex esr spectrum. Anodic oxidation of hexamethylbenzene in trifluoroacetic acid at concentrations greater than 1 O M yields the radical-cation I by the process shown in Scheme 6.1 [14], Preparative scale, anodic oxidation of methylbenzenes leads to the benzyl carbonium ion by oxidation of the benzyl radicals formed from the substrate radical-cation. Products isolated result from further reactions of this carbonium ion. 

Thus, although the colour of sparks is dependent upon flame temperature and may be similar to that of black body radiation, the overall colour effect can include contributions from atomic line emissions, from metals (seen in the UV and visible regions of the electromagnetic spectrum), from band emissions from excited oxide molecules (seen in the UV, visible and IR regions) and from continuum hot body radiation and other luminescence effects. So far as black body radiation is concerned, the colour is known to change from red (500 °C glowing cooker... 

Oxidation products from tetrahydropapaveroline with potassium ferricyanide were reinvestigated by Mak and Brossi 21), who confirmed structure 28 for the initial product. Air oxidation of 29 gave after acetylation a product with the same physical properties reported by Harley-Mason, but its mass spectrum showed a parent ion at m e 900 and molecular composition C48H40N2O16, suggesting it to be a dehydro dimer of 12. The H-NMR spectrum of the dimer showed that the double bonds at the 5,6 positions were intact. The point of dimerization was determined by comparing the multiplicities of carbons in the C-NMR spectra of the dimer and dibenzopyrrocoline models. For monomeric compounds the peak ascribed to C-12 in compound 11 was a triplet and a doublet in 12, but a singlet in the dimer. Thus, the products from oxidation of 28 had structures 31 and 32 rather than 29 and 30, respectively. 

The Bi203—Sn02 combination was studied by Solymosi and Bozso [299] and by Seiyama et al. [284,285]. The former carried out pulse experiments in the absence of oxygen and report that even small amounts of Sn02 added to Bi203 have a promoting effect and shift the product spectrum from hexadiene to benzene. The best combination is a mechanical mixture of the two oxides in a 1/1 ratio. With this catalyst, a selectivity of 80% (benzene) is reached at a 40% conversion level (at 500° C),... 

Figure 20. Residual spectrum from an ozone-propylene-S02 reaction and H2S04 aerosol spectrum from the HO-initiated oxidation of S02 (see text).

Iron oxide painted rabbit hair with albumin binder Bedstraw dyed common milkweed, charred 20 min Malachite (spectrum from IRUG) Seip 36, charred bast, red cast, Fe... 

Iron oxide Aqueous bedstraw extract Verdigris (spectrum from IRUG) Seip 10, red/brown hair and bast, composite, not charred... 

The N(ls) spectrum from this surface obtained at an exit angle of 15° (Fig. 12) shows the high binding energy component characteristic of amines that have been protonated by the oxide hydroxyls. The low intensity of the N(ls) spectra obtained at steeper exit angles prevented accurate curve fitting of these spectra. 

Exposure of C70H38 for 1 month to air (Fig. 7.12, third spectrum from top) show a much more intense ketone band, this time split at 1,733 and 1,709 cm-1 combined with intense OH stretching and bending respectively at 3,384 and 1,032 cm-1. The oxidation in such sample can be considered extensive. 

A survey and carbon Is spectrum from untreated white pine is shown in Figure 36. Survey spectra and chlorine 2p as well as carbon Is spectra are shown in Figure 37 taken from white pine treated with hydrogen peroxide, HCL, and acetic acid with heating. This oxidative treatment has oxidized carbon as evidenced by shoulders in the C Is spectra at higher binding energies and introduced carbon chlorine bonds on the surface as evidenced by the chlorine 2p line around 200 eV. 

Figure 37. Electron spectrum from surface oxidized white pine.

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