Theoretical and experimental vibrational study of polyaniline in base forms: non-planar analysis. Part I

Abstract

Experimental and theoretical studies of basic forms of polyaniline are presented. Experimental spectra of emeraldine, leucoemeraldine and pernigraniline and their oligomer model compounds (diphenylamine, phenyl‐end‐capped dimer, phenyl‐end‐capped tetramer, phenyl‐end‐capped hexamer, imine form of phenyl‐end‐capped dimer, pernigraniline base phenyl‐end‐capped tetramer and emeraldine base phenyl‐end‐capped tetramer) were recorded in N‐methyl‐2‐pyrrolidone solution and in the solid state. The calculations were performed using the valence force field model. A non‐planar geometry of the polymers studied was taken into consideration and particular phenylene ring torsions rendering the system non‐planar were analyzed. The assignments of the observed modes was made possible by comparison of the calculated and experimentally measured wavenumbers. Copyright © 2000 John Wiley & Sons, Ltd.

Synthesis and Characterization of PSSA-Polyaniline Composite with an Enhanced Processability in Thin Films

“…From the recorded spectrum of PANI-EB (Fig. 2b) one can observe the characteristic peak at 1593 cm -1 , which is due to the C=C stretching in the quinoid ring, the 1378 cm -1 peak typical for C-N stretching [22][23][24].…”

Spectroscopy of Polyaniline Nanofibers

“…However, it was often observed that the quality of the products such as the shape and stability of their dispersions varies with different synthetic conditions, such as, stirring, temperature and pH, among others. (Colomban et al, 1999;Cochet et al, 2000a;Cochet et al, 2000b) have been demonstrated that the low energy Raman bands from 100 to 600 cm -1 in the PANI spectra are very sensible to the crystalline arrangement and also to the conformational changes of the PANI chains. The Raman spectra of PANI nanofibers prepared from interfacial polymerization were obtained at low wavenumbers.…”

“…In addition, shifts of the bands from 393-427 cm -1 to 422-451 cm -1 are also seen for PANI nanofibers prepared with higher HCl concentration. (Cochet et al, 2000a;Cochet et al, 2000b) demonstrated that mainly the bands at about 200-500 cm -1 are very sensible to the conformational changes. The shift to higher wavenumbers of the bands at about 400 cm -1 indicates the increase of the torsion angles of the C ring -N-C ring segments.…”

Nanocompósitos eletroativos de poli-o-metoxianilina e polissacarídeos naturais

“…Alguns picos Raman característicos da POMA-ES são: 577 cm -1 atribuído à deformação da amina no plano, 1356 cm -1 atribuído ao cátion radical (estiramento C-N + ) e 1597 cm -1 atribuído ao estiramento C-C do anel benzeno. A Tabela 1 traz os picos Raman da base e do sal de POMA esmeraldina, e suas respectivas atribuições, as quais são "atribuições tentativas" baseadas nas referências [30][31][32][33][34][35] que se referem à PANi.…”