Lattice dynamics and vibrational spectra of pristine and doped polypyrrole: Effective conjugation coordinate

Abstract

A detailed vibrational analysis of the infrared and Raman spectra of doped and pristine polypyrrole is presented. The theory of the effective conjugation coordinate is applied and fully justifies the observed spectra. The information on the structure and properties of this material derived from the proposed analysis are presented and discussed.

Infrared investigations of pristine, doped and partially doped polypyrrole

“…Zerbi's nomenclature we have labeled these peaks A' through G' (9). This spectrum also shows the featureless rise in absorbance with energy at energies above ca.…”

“…In fact, however, the intensities of all of the bands are enhanced upon doping. The C, E, and G bands appear in the doped spectrum because they are infrared active modes of the fraction of the material which remains undoped (in the predominantly doped material) or analogous modes unique to the fraction of material which is doped (9). The increase in intensity of these bands with doping may result from coupling of the vibrational modes with oscillations of the charge carriers in the doped polymer (22).…”

Operational electrochemical stability of thiophene-thiazole copolymers probed by resonant Raman spectroscopy

“…22 Raman spectroscopy is sensitive to the polarisability of molecules, which in turn depends upon the molecular conformation and effective conjugation length. 27,31,37 Therefore, the differences in the Raman spectra measured with different excitation wavelengths can provide information about particular morphological phases (ordered or disordered) present in the polymer samples studied here. 22 Figure 4 compares the Raman spectra of pristine and degraded PTTz films using several excitation wavelengths (785, 514, 488, and 457 nm).…”

“…[34][35][36][37][38][39] In each case, the ground-state geometries of the molecules were first optimized in the gas phase (the hexyl side chains were replaced by methyl side groups to reduce computation time) and the Raman spectra of these optimized structures were then calculated ( Figure SI.1 40 ). …”

Design and synthesis of inorganic–organic hybrid microstructures

“…FTIR spectra from 4800-400 cm' 1 were recorded from KC1 pellets with a Nicolet 510P spectrophotometer. Tian and Zerbi's "effective conjugate coordinate" (ECC) theory explains relations between PPy's vibrational spectrum and properties [13,14]. Structural changes which occur during polymerization of the monomer as well as the approximate doping level of the polymer are correlated with the spectral features.…”