Regiospecifically Alkylated Oligothiophenes via Structurally Defined Building Blocks

Abstract

We have developed a new synthetic protocol for the unsymmetrically alkylated and halogenated terthiophenes 5 and 10. To demonstrate their usefulness as building blocks for well-defined oligothiophenes, we synthesized a series of seven new sexi-, septi- and octithiophenes. Terthiophene 5 could be dimerized to the didecylsexithiophene In6 and terthiophene 10 to sexithiophene Out6, respectively, by the use of nickel catalysis. Together with the bis-stannylated thiophenes 11 and 12, the septithiophenes In7 and Out7 as well as the octithiophenes In8 and Out8 could be obtained via Stille coupling methodology. We could also obtain the unsymmetrical sexithiophene Unsym6 by selective heterocoupling between one equivalent of terthiophene 5 and 10 each. All new sexi-, septi- and octithiophenes show high photoluminescence in solution, but the quantum yield drops sharply in thin films of the materials.

Key words

regioselectivity - halogenation - alkylations - coupling - oligothiophenes - luminescence

References

• 1 For example, see: Neugebauer H. Sariciftci NS. Kuzmany H. Resel R. Leising G. Synth. Met.  2001,  120:  663 -1092
• 2 Andersson MR. Thomas O. Mammo W. Svensson M. Theander M. Inganäs O. J. Mater. Chem.  1999,  9:  1933 
• 3a Garnier F. Yassar A. Hajlaoui R. Horowitz G. Deloffre F. Servet B. Ries S. Alnot P. J. Am. Chem. Soc.  1993,  115:  8716 
• 3b Garnier F. Hajlaoui R. Yassar A. Srivastava P. Science  1994,  265:  1684 
• 4a McCullough RD. Ewbank PC. In Handbook of Conducting Polymers   2nd ed.:  Skotheim TA. Elsenbaumer RL. Reynolds JR. Marcell Dekker; New York: 1998.  Chap. 9. p.225-258  
• 4b McCullough RD. Adv. Mater.  1998,  10:  1 
• 4c McCullough RD. Lowe RD. J. Chem. Soc., Chem. Commun.  1992,  70 
• 4d McCullough RD. Lowe RD. Jayaraman M. Anderson DL. J. Org. Chem.  1993,  58:  904 
• 4e McCullough RD. Tristram-Nagle S. Williams SP. Lowe RD. Jayaraman M. J. Am. Chem. Soc.  1993,  115:  4910 
• 4f McCullough RD. Williams SP. J. Am. Chem. Soc.  1993,  115:  11608 
• 4g McCullough RD. Jayaraman M. J. Chem. Soc., Chem. Commun.  1995,  135 
• 4h Chen T.-A. Rieke RD. J. Am. Chem. Soc.  1992,  114:  10087 
• 4i Chen T.-A. Rieke RD. J. Am. Chem. Soc.  1995,  117:  233 
• 4j Wu X. Chen T.-A. Rieke RD. Macromolecules  1995,  28:  2101 
• 4k Bouman MM. Meijer EW. Adv. Mater.  1995,  7:  385 
• 4l Loewe RS. Ewbank PC. Liu J. Zhai L. McCullough RD. Macromolecules  2001,  34:  4324 
• 5 Johansson DM. Theander YM. Srdanov G. Yu G. Inganäs O. Andersson MR. Macromolecules  2001,  34:  3716 
• 6 Theander YM. Svensson M. Ruseckas A. Zigmantas D. Sundström V. Andersson MR. Inganäs O. Chem. Phys. Lett.  2001,  337:  277 
• For example, see:
• 7a Gronowitz S. Peters D. Heterocycles  1990,  30:  645 
• 7b Charloner PA. Gunatunga SR. Hitchcock PB. J. Chem. Soc., Perkin Trans. 2  1997,  8:  1597 
• 7c Rossi R. Carpita A. Ciofalo M. Houben JL. Gazz. Chim. Ital.  1990,  120:  793 
• For example, see:
• 8a Beny J.-P. Dhawan SM. Kagan J. Sundlass S. J. Org. Chem.  1982,  47:  2201 
• 8b Perrine DM. Kagan J. Heterocycles  1986,  24:  365 
• For example, see:
• 9a Merz A. Ellinger F. Synthesis  1991,  462 
• 9b Wynberg H. Metselaar J. Synth. Commun.  1984,  14:  1 
• 9c Kagan J. Arora SK. Heterocycles  1983,  20:  1941 
• For example, see:
• 10a Eachern AM. Soucy C. Leitch LC. Arnason JT. Morand P. Tetrahedron  1988,  44:  2403 
• 10b Nakayama J. Konishi T. Murabayashi S. Hoshino M. Heterocycles  1987,  26:  1793 
• 10c Effenberger F. Grube G. Synthesis  1998,  1372 
• 10d Jones CL. Higgins SJ. J. Mater. Chem.  1999,  4:  865 
• 10e Bäuerle P. Pfau F. Schlupp H. Würthner F. Gaudl K.-U. Caro MB. Fisher P. J. Chem. Soc., Perkin Trans. 2  1993,  3:  489 
• 11 Kelin AV. Kulinkovich OG. Synthesis  1996,  330 
• 12 Encyclopedia of Reagents for Organic Synthesis   Vol 1:  Wiley; New York: 1995.  p.530-533  ; and references cited therein
• 13a Freeman F. Kim Darrick SHL. Rodriguez E. J. Org. Chem.  1992,  57:  1722 
• 13b Steliou K. Mrani M. J. Am. Chem. Soc.  1982,  104:  3104 
• 14 Destri S. Ferro DR. Khotina IA. Porzio W. Farrina A. Macromol. Chem. Phys.  1998,  199:  1973 
• 15 Wei Y. Yang Y. Yeh J.-M. Chem. Mater.  1996,  8:  2659 
• 16 Galli C. Synthesis  1979,  303