Electronic structure of oligoaniline doped by inorganic and organic acids

Abstract

ABSTRACT:The electronic structure of doped-oligoaniline with various dopants is investigated by means of DFT method. After doping by hydrochloric acid (HCl) and camphorsulfonic acid (HCSA), the alternation of bond-lengths is decreased and the coplanarity of adjacent aromatic rings is increased. The -conjugating effect is increased in the electronic nature of Ph-N system because the electrons can be delocalized along the backbone of oligoaniline where the hydrogen bonds as a bridge transfer the electrons. The electronic structure of polaron and bipolaron conformation and their relative stability is discussed, indicating that the preferable conformation is dependant on various dopants. The calculation results reveal that there is a relatively stronger interaction between the organic dopant of HCSA and N atoms of PANI, and more charge transfer between PANI and HCSA is a reason for the fact that the conductivity of HCSA-doped PANI is higher than that of HCl-doped PANI. The doping mechanism is proposed based on the calculation results.

FTIR, Raman and NMR spectroscopic and DFT theoretical studies on poly(N-vinylimidazole)

“…A large number of quantum mechanical studies have been devoted to study the structural and electronic properties of conducting oligomers and polymers derived from thiophene and pyrrole [16][17][18][19][20]. These investigations have been extremely useful not only to rationalize the experimental observations but also to develop the comprehensive design of new conducting materials by using the knowledge provided by such calculations.…”

“…These investigations have been extremely useful not only to rationalize the experimental observations but also to develop the comprehensive design of new conducting materials by using the knowledge provided by such calculations. In the last decade some theoretical studies have been devoted to study oligoanilines and/or PAn using ab initio and/or Density Functional Theory (DFT) methods [20]. To the best our knowledge, there have been no reports in the literature about the DFT study on water-soluble poly(NVIM).…”

Intrinsically Tuning the Electromechanical Properties of Elastomeric Dielectrics: A Chemistry Perspective

“…In DFT studies, bulky organic acids have been shown to increase the electronic properties of aniline containing polymers . Furthermore, CSA is able to interact with the nitrogen in oligoaniline, stabilizing the dopant in the polymer. It is hypothesized that the acid enables a greater electron transfer between the acid and the aniline, enhancing the conductivity between the two.…”

Functional block-like structures from electroactive tetra(aniline) oligomers

“…The study by Hou and co-workers considers tetraanilines as well as dodeca-and hexadecamers, along with two different dopant acids. 132 The results for doping with HCl show increased planarity of the backbone and a more benzenelike structure, with the extent of electron delocalisation influenced by the size of the model compound considered; the authors focussed their discussion on hexadecamers. This work also considered the structural effects of a second dopant, camphor sulfonic acid (CSA), found to cause more pronounced structural changes and increased electron delocalisation in the polaron form, in line with increased conductivity as observed experimentally.…”