Theoretical analysis of counterfoil influence over the physicochemical properties of aniline tetramers in several oxidation states
- 57 Downloads
We present semiempirical quantum chemical calculations of geometric structures, charge distributions, energy levels, ionization potentials, and enthalpies of formation for aniline tetramers in different oxidation states using the semiempirical AM1 method. For tetraaniline radical cation the effect of these three counterions on the above-mentioned physicochemical parameters was analyzed. The ions studied included Cl−, HSQ4−, and CH3COO−. Chloride counterion showed a large charge transfer to the chain, as was shown in a preceding work . HSO4− showed a strong charge stabilization without transfer. CH3COO− exhibits hydrogen bond formation and also displays a strong charge stabilization in a fragment of the chain, but does not transfer any charge. Also, Cl− was able to form a hydrogen bond, depending on the initial position that it occupies in relation to the tetrameric chain, which is then optimized. Charge transfer is present for the Cl− cases. For dication structures the effect of SO 4 2− was analyzed. Our calculations showed that the distribution of the energy levels of tetraaniline radical cation can be comparable to the polyaniline ones by adding a counterion to the tetramer.
Key wordsOligoaniline polyaniline anions charge transfer
Unable to display preview. Download preview PDF.
- 4.Epstein, A. J. InConjugated Polymers. The Novel Science and Technology of Highly Conducting and Nonlinear Optically Active Materials; Brédas, J. L.; Silbey, R. S., Eds.; Kluwer: Dordrecht, The Netherlands, 1991; p. 211.Google Scholar
- 9.Evans, G. P. InAdv. Electrochem. Sci. Eng., Vol. 1; Gerischer, H.; Tobias, C. W., Eds.; Verlag Chemie (VCH): New York, 1990, p. 1.Google Scholar
- 14.Vaschetto, M. E.; Retamal, B. A.; Contreras, M. L.; Zagal, J. H.; Bulhoes, L. O. S.Struct. Chem. 1995,6, 129.Google Scholar
- 15.MOPAC ver 6.0, in Insight II of Biosym Technologies, San Diego, User Guide, ver. 2.2.0, 1993.Google Scholar
- 17.Vaschetto, M. E.Doctoral Thesis, Universidad de Santiago de Chile, 1995.Google Scholar
- 21.Kang, E. T.; Neoh, K. G.; Tan, K. L.Adv. Polym. Sci. 1993,106, 135.Google Scholar