Novel Fluorophores: Efficient Synthesis and Photophysical Study Gil Tae Hwang, Hyung Su Son, Ja Kang Ku, and Byeang Hyean Kim* Center for Integrated Molecular Systems, Department of Chemistry, DiVision of Molecular Life Science, Pohang UniVersity of Science and Technology, Pohang 790-784, Korea bhkim@postech.ac.kr Received June 4, 2001 ABSTRACT We have synthesized novel fluorophores by using Sonogashira reactions of 1,4-bis(dibromovinyl)benzene and 2,5-bis(dibromovinyl)thiophene with various aromatic bromides. The emission maxima of these fluorophores vary from the indigo blue to the reddish-orange region, depending on the structures of aromatic nuclei and peripheral moieties. Organic molecules with high photoluminescence efficiencies have recently attracted increasing attention in various research fields as advanced materials for electronic and photonic applications. 1,2 Thus, it is important to synthesize efficiently novel fluorophores that are amenable to further chemical functionalization or modification, which in turn is essential to obtain materials with tunable optoelectronic properties. 1,1-Dibromo-1-alkenes 1 are conveniently prepared by the procedure of Corey and Fuchs. 2 They can be converted to (Z)-1-bromo-1-alkenes 2, 3 (Z)-1-aryl(alkenyl)-1-bromo-1- alkenes 3, 4 1,1-diaryl(alkenyl)-1-alkenes 4, 5c 1-aryl(alkenyl)- 1-alkynes 5, 3,5c and 1,3-diynes 6 6 (Scheme 1). However, few studies on the Sonogashira reaction 7 of 1,1-dibromo-1- alkenes have been reported. Furthermore, to the best our knowledge, there is no precedent for the synthesis of fluorophores by using this approach, which may provide (1) (a) Seminario, J. M.; Tour, J. M. In Molecular ElectronicssScience and Technology; Aviran, A., Ratner, M., Eds.; New York Academy of Science: New York, 1998. (b) Mu¨llen, K., Wegner, G., Eds. In Electronic Materials: The Oligomer Approach; Wiley-VCH: New York, 1998. (2) For recent reviews, see: (a) de Silva, A. P.; Gunaratne, H. Q. N.; Gunnlaugsson, T.; Huxley, A. J. M.; McCoy, C. P.; Rademacher, J. T.; Rice, T. E. Chem. ReV. 1997, 97, 1515. (b) Kraft, A.; Grimsdale, A. C.; Holmes, A. B. Angew. Chem., Int. Ed. 1998, 37, 402. (c) Sheats, J. R.; Chung. Y. L.; Roitman, D. B.; Stocking, A. Acc. Chem. Res. 1999, 32, 193. (d) Yamaguchi, S.; Endo, T.; Uchida, M.; Izumizawa, T.; Furukawa, K.; Tamao, K. Chem. Eur. J. 2000, 6, 1683. (3) Corey, E. J.; Fuchs, P. L. Tetrahedron Lett. 1972, 4831. Scheme 1 ORGANIC LETTERS 2001 Vol. 3, No. 16 2469-2471 10.1021/ol0162264 CCC: $20.00 © 2001 American Chemical Society Published on Web 07/19/2001