Theoretical studies on polyaniline

Abstract

Theoretical predictions for various neutral and charged forms of polyaniline are presented and discussed. The MNDO semiempirical method is used to predict geometries which serve as input for valence effective Hamiltonian (VEH) calculations of the electronic band structure. The VEH calculations provide predictions for the band gaps, ionization potentials, electron affinities, and redox potentials for the various forms of polyaniline. Where possible, comparison is made to experiment with generally favorable results. The discussion emphasizes the electrochemistry of polyaniline and the structural evolution of the polymer during electrochemical oxidation and reduction.

On the possibility of grafting conducting polymers into insulating ones

“…In Table 1, we present the heats of formation of these compounds obtained by full optimization of the geometric structures. The benzoid form of the PAn dimer is more stable in the gas phase than the quinoid-benzoid form, as previously reported [ 15,18,19]. Pyrrole dimers can be obtained by various linkages between (Y and p carbons.…”

Delineating Poly(Aniline) Redox Chemistry by Using Tailored Oligo(Aryleneamine)s: Towards Oligo(Aniline)‐Based Organic Semiconductors with Tunable Optoelectronic Properties

“…As highlighted in Figure 2, our molecular engineering approach to the central p-conjugated units in the rest of the series now allows for large and tunable modifications of the electronic structure of the different TANIs, resulting in bathochromic shifts of up to 24 nm and hypsochromic shifts of up to 90 nm for the first and second transitions, respectively. For 1EB and 2EB the two absorption maxima (l 1max and l 2max ) have previously been assigned to p-p* and n-p* transitions, respectively, based on theoretical [30,31] and experimental [32][33][34] studies of polyA C H T U N G T R E N N U N G (aniline) (PANI). However, more recent work [35] on oligoA C H T U N G T R E N N U N G (aniline)s suggested that l 2max is actually a further p-p* transition.…”

Electronic Phenomena in Polyanilines

“…5 together with the results of a Huckel calculation for the electronic band structure of LEB carried out assuming that the repeat unit is a single (C 6 H 4 NH) unit [25,26]. This simple calculation reproduces most of the band structure features obtained in more extensive calculations [27,28,29]. The seven energy bands are derived from the six Pz energy levels of benzene together with the Pz energy level of nitrogen.…”