Conducting discotic polyaromatic material with two unpaired electrons at oxidized state: Synthesis and properties.

Mohamed Jouini 

CNRS - Université Denis Diderot, ITODYS (ITODYS), Place Jussieu, Paris F-75005, France

Abstract
Polyaromatic molecules having symmetry axis equal or larger than three, possess degenerate HOMO’s and LUMO’s. This opens the possibility to abtain radical anions or cations in a high spin state. Oragnic molecules having high spin state are attractive in the search of electrical conductivity, ferromagnetism and even superconductivity[1]. Polyaromatic hydrocarbons are of interest as high spin-systems, because many of the monoradicals and diradicals are relatively stable systems. [2]

We report the electrohemical oxidation in acetonitrile of hexapyrrolyl benzene (HPyB) a polyaromatic heterocyclic compound. This oxidation leads to a discotic polyaromatic heterocyclic material (HPyB6a) and not to a linear polymer. [3] The electroactivity of this material shows two successive reversible redox waves corresponding to the transfer of two electrons and esr measurements at oxidized sate shows paramagnetic behaviour at room temperature.

[1] F. Demol, F. X. Sauvage, A. Devos, M.G. De Backer, Synth. Met., 99 (1999) 155.

O. Lemaire, M. De Backer, A. Devos, F. X. Sauvage, Synth. Met., 123 (2001) 61.

[2] F. Dietz, N. Tuytuylkov, G. Madjarova, K. Mullen, J. Phys. Chem. B, 104 (2000) 1746.

N. Tuytuylkov, G. Madjarova, F. Dietz, K. Mullen, J. Phys. Chem. B, 102 (1998) 10183.

[3] M. Lazerges, M. Jouini, P. Hapiot, P. Guiriec, P.-C. Lacaze, J. Phys. Chem. B, 107 (2003) 5042.

 

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Presentation: Invited at E-MRS Fall Meeting 2007, Symposium D, by Mohamed Jouini
See On-line Journal of E-MRS Fall Meeting 2007

Submitted: 2007-05-14 19:08
Revised:   2009-06-07 00:44