Abstract
Oxidative doping of individual thiophene oligomers nT (n = 3 to 6) with FeC13 in dilute CH2Cl2 solution generates the corresponding radical cations (polarons) nT+.. as evidenced by in-situ visible/near infrared absorption and electron spin resonance spectroscopies. The nT+. species in solution progressively precipitate as conducting (0′300K = 10−1−10−2 S/cm) and strongly paraaagnetic radical cation salts (g = 2.003, ΔHPP ∼ 4–8 G). The conductivity of the 6T+. salt is weakly temperature dependent, with an activation energy of 32 meV above 100 K and a tendency to level Dff at lower temperatures. In the case of the sexithienyl radical 6T+., further doping results in the quantitative conversion into the dication 6T++ (bipolaron).
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(a) T.-C. Chung, J.H. Kaufman, A.J. Heeger and F. Vudl, Phys. Rev. Β 30, 702 (1984). (b) K. Kaneto, Y. Kohno and K. Yoshino, Mol. Cryst. Liq. Cryst. 118, 217 (1985).
D. Bertho and C. Jouanin, Phys. Rev. Β 35, 626 (1987).
S. Stafström and J.L. Brédas, Phys. Rev. Β 38, 4180 (1988).
(a) D. Fichou, G. Horowitz and F. Gamier, in press, (b) Z. Xu, D. Fichou, G. Horowitz and F. Garnier, J. Electroanal. Chem. 267, 339 (1989).
(a) D. Fichou, F. Garnier, F. Charra, F. Kajzar and J. Messier, in “Organic Materials for Nonlinear Optics”, eds. R. Hahn and D. Bloor, Royal Society of Chemistry, London, pp.176 (1989).
(a) G, Horowitz, D. Fichou and F. Garnier, Solid State Commun. 70, 385 (1989). (b) G. Horowitz, D. Fichou, X. Peng, Z. Xu and F. Garnier, Solid State Commun., in press.
(a) J. Kagan and S. Arora, Heterocycles, 20, 1937 (1983). (b) J. Kagan and S. Arora, Tetrahedron Lett., 24, 4043 (1983).
G. Vincow, in “Radical Ions”, eds. E.T. Kaiser and L.Kevan, (Interscience, Hew-York, 1968), pp. 151.
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Fichou, D., Horowitz, G. Generation of Stable Radical Cations (Polarons) and Dications (Bipolarons) on Model Thiophene Oligomers. MRS Online Proceedings Library 173, 379–384 (1989). https://doi.org/10.1557/PROC-173-379
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DOI: https://doi.org/10.1557/PROC-173-379