Department of Chemistry Seminar Announcement Date/Time/Venue Title/Speaker 11 Mar (Fri) 3pm – 4pm Synthesis and photophysical properties of pyrenebased light-emitting monomers: highly blue fluorescent multiply-conjugated-shaped architectures @ S8 Level 3 Executive Classroom Professor Takehiko Yamato Saga University, Japan Host : Asst Prof Wu Jishan About the Speaker Professor Takehito Yamato (大和武彦) was born in Fukuoka, Japan in 1953. He graduated in 1975 with a BS from Kyushu Institute of Technology and thereafter in 1983 with a PhD from Kyushu University. He carried out his postdoctoral research at State University of New York at Stony Brook with Prof Iwao Ojima and University of Southern California with Prof G A Olah, Novel prize 1995 (1983-1985). He joined the faculty in the Department of Applied Chemistry at Saga University in 1986 and is currently a Professor of Chemistry. His research field focuses on synthetic organic chemistry, supramolecular chemistry and development of OLED materials. Abstract Recently, pyrene derivatives have been turned out to be promising candidates for several applications like organic light-emitting diodes (OLEDs) due to its desirable photophysical properties. Previously we have reported the syntheses of series of pyrene-based blue light-emitting monomers using the tert-butyl group as a positional protective function.1,2 In this talk we will discuss the synthesis and photophysical properties of new series of pyrene-based cruciform-shaped -conjugated monomers as well as the relationship between the substituents and positions.3,4 A new series of pyrene-based, highly pure blue fluorescent and stable monomers, namely 2,7-di-tert- butyl4,5,9,10-tetrakis(p-substituted phenylethynyl)pyrenes, have been successfully synthesized via a Pd/Cu-catalysed Sonogashira coupling reaction in excellent yield. As revealed from single-crystal X-ray analysis, there is a herring-bone pattern between stacked columns but the - stacking distance (ca. 5.82 Å) of adjacent two pyrene units are not especially short at ca. 3.50–3.70 Å due to the introduction of the two bulky tert-butyl groups in pyrene rings at 2 and 7 positions. Their photophysical properties were carefully examined in different organic solvents and these data strongly indicate their promising application as blue-emitting materials in organic light-emitting diodes (OLEDs). [1] T. Yamato, M. Fujimoto, A. Miyazawa and K. Matsuo, J. Chem. Soc. Perkin Trans. 1, 1201 (1997). [2] T. Yamato, S. Miyamoto, T. Hironaka and Y. Miura, Org. Lett., 7, 3 (2005). [3] J. Hu, M. Era, M.R.J. Elsegood and T. Yamato, Eur. J. Org. Chem., 2010, 72–79. [4] X. Ni, S. Wang, X. Zeng, Z. Tao and T. Yamato, Org. Lett. in press. All are Welcome R R 10 4 9 5 R R 1 a: R = H (65%) b: R = t-Bu (68%) c: R = OMe (75%) X-ray structure of 1c