Spectroscopic analysis polyaniline

In addition to functionalization of polyanilines with sulfonic and carboxylic acids, the corresponding phosphonic acid derivatives have been prepared, o-Aminobenzylphosphonic acid was prepared as shown in Figure 20.54 [42,43]. Oxidative coupling of the above monomer in an acidic medium yielded poly(o-aminobenzylphosphonic acid) (Figure 20.55). Spectroscopic analysis was consistent with head-to-tail oxidative coupling through the /Jara-position. The as-prepared polymer was in its emeraldine oxidation state in which 43% of the N-atoms were protonated by the pendent acid. This polymer was insoluble in both non-aqueous solvents and aqueous acidic solutions. 

Besides synthesis, current basic research on conducting polymers is concentrated on structural analysis. Structural parameters — e.g. regularity and homogeneity of chain structures, but also chain length — play an important role in our understanding of the properties of such materials. Research on electropolymerized polymers has concentrated on polypyrrole and polythiophene in particular and, more recently, on polyaniline as well, while of the chemically produced materials polyacetylene stih attracts greatest interest. Spectroscopic methods have proved particularly suitable for characterizing structural properties These comprise surface techniques such as XPS, AES or ATR, on the one hand, and the usual methods of structural analysis, such as NMR, ESR and X-ray diffraction techniques, on the other hand. 

Soluble polythiophenes, 317 Soluble precursor route, 295 Solvatochromism, 329, 593 Solvent and solution pH, 431 Spectroelectrochemistry, 834 Spectroscopic methods, 535 Spin density, 837 Spiro oligothiophenes, 635 Structural analysis, 3 Structural nature, 2 Structure of polytoluidines, 575 Substituted polyanilines, 532, 619 Substituted pyrroles, 442 Sulfonates, 833... 

Fig. 19.68 X-ray photoelectron spectroscopic (XPS) analysis of passive iron oxide layers form in the presence of doped polyaniline. (From Ref. 83.)...

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