ORGANIC
LETTERS
2003
Vol. 5, No. 11
1817-1820
Preparation and Characterization of
r,r′-Bisdiarylamino-Capped
Oligothiophenes
Ahcene Tabet, Anke Schro1der, Horst Hartmann,* Dirk Rohde,† and
Lothar Dunsch†
UniVersity of Applied Sciences, Geusaer Strasse, D-06217 Merseburg, Germany, and
IFW Dresden, Abtl. Elektrochemie und leitfa¨hige Polymere, Dresden, Germany
Received February 24, 2003
ABSTRACT
A series of r,r′-bisdiarylamino-capped oligothiophenes C were prepared by the palladium-catalyzed reaction of the dibromo compounds A
n
i
with diarylamines, N,N-diarylamino-substituted thiophenes or 2,2′-bithiophenes BX. These easily oxidizable compounds exhibit a high tendency
j
to form amorphous glasses and characteristic electrochemical and spectroscopic properties that depend significantly on the number of their
thiophene moieties.
Owing to their unique electronic and optical properties,
oligothiophenes with well-defined structures1 are of great
interest for new materials used in several fields of applica-
tions, such as field-effect transistors,2 organic light-emitting
diodes,3 or photocopiers.4 To diversify the structure and,
hence, the properties of the oligothiophenes, the introduction
of different terminal groups into their backbone is a growing
synthetic interest. For instance, a series of oligothiophenes
substituted at their R,R′-positions by 9,9-diphenylfluorene
moieties 4na5 or electron-accepting cyano or perfluorohexyl
groups 4nb6 and 4nc,7 respectively, have been prepared and
studied recently. Moreover, oligothiophenes 5nd with pyr-
rolidino groups at their â,â′-positions and n ) 0-2 have
also been reported recently. These compounds render, e.g.,
versatile starting materials for electroactive polymers.8 The
essential step in the synthesis of the mentioned oligothio-
phenes consists of a heavy-metal-catalyzed coupling reaction
of a metalated thiophene 2 or 3 with 2,5-dihalothiophene 11
or 5,5′-dihalo-2,2′-bithiophene 12. The same 2,5-dihalo
compounds 1i have also been used as starting materials for
the synthesis of the first two members of diarylamino-capped
oligothiophenes of the general structure 9n (n ) 1 or 2)9,10
if they were allowed to react with diarylamines. The 2,5-
(6) Yassar, A.; Demanze, F.; Jaafari, A.; El Idrissi, M.; Coupry, C. AdV.
Funct. Mater. 2002, 12, 699.
(7) Facchetti, A.; Mushrush, M.; Katz, H. E.; Marks, T. J. AdV. Mater.
2003, 15, 33.
† IFW Dresden, Abtl. Elektrochemie und leitfa¨hige Polymere.
(1) Fichou, D. Handbook of Oligo- and Polythiophenes; Wiley-VCH:
Weinheim, 1999.
(2) Horowitz, G.; Garnier, F.; Yassar, A.; Hajlaoui, R.; Kouki, F. AdV.
Mater. 1996, 8, 52.
(8) Go¨tz, G.; Scheib, S.; Klose, R.; Heinze, J.; Ba¨uerle, P. AdV. Funct.
Mater. 2002, 12, 723.
(3) (a) Rothberg, L. J.; Lovinger, A. J. J. Mater Res. 1996, 11, 3174. (b)
Ju¨stel, T.; Nikol, H.; Ronda, C. Angew. Chem. 1998, 110, 3251; Angew.
Chem., Int. Ed. 1998, 37, 3084.
(4) (a) Wu¨rthner, F.; Yao, S.; Schilling, J.; Wortmann, R.; Redi-Abshiro,
M.; Mecher, E.; Gallego-Gomez, F.; Meerholz, K. J. Am. Chem. Soc. 2001,
123, 2810. (b) Keil, D.; Flaig, R.; Schroeder, A.; Hartmann, H. Dyes Pigm.
2001, 50, 67.
(9) (a) Yamamoto, T.; Nishiyama, M.; Koie, K. Tetrahedron Lett. 1998,
39, 627. (b) Yamamoto, T.; Nishiyama, M.; Watanabe, M. Japanese Patent
256295, 2000; Chem. Abstr. 2002, 133, 252295. (c) Yamamoto, T.;
Nishiyama, M.; Watanabe, M. Japanese Patent 256351, 2000; Chem. Abstr.
2002, 133, 237848.
(10) (a) Wong, K.-T.; Hung, T. H.; Kao, S. C.; Chou, C. H.; Su, Y. O.
Chem. Commun. 2001, 1628. (b) Kisselev, R.; Thelakkat, M. Chem.
Commun. 2002, 1530. (c) Gerstner, P.; Rohde, D.; Hartmann, H. Synthesis
2002, 2487.
(5) Wong, K.-T.; Wang, C.-F.; Chou, C. H.; Su, Y. O.; Lee, G.-H.; Peng,
S.-M. Org. Lett. 2002, 4, 4439-4442.
10.1021/ol034322u CCC: $25.00 © 2003 American Chemical Society
Published on Web 04/30/2003