synthesis of a highly luminescent three-dimensional pyrene dye based on the spirobifluorene skeleton高度三维芘荧光染料的合成基于spirobifluorene骨架.pdfVIP

Molecules 2010, 15, 7582-7592; doi:10.3390/molecule OPEN ACCESS molecules ISSN 1420-3049 /journal/molecules Communication Synthesis of a Highly Luminescent Three-Dimensional Pyrene Dye Based on the Spirobifluorene Skeleton Kentaro Sumi and Gen-ichi Konishi * Department of Organic and Polymeric Materials, Graduate School of Science and Engineering, Tokyo Institute of Technology, Japan * Author to whom correspondence should be addressed; E-mail: konishi.g.aa@m.titech.ac.jp. Received: 24 August 2010; in revised form: 25 October 2010 / Accepted: 27 October 2010 / Published: 28 October 2010 Abstract: We have synthesized a highly luminescent (log ε 5.0, Φ 0.9) pyrene dye based on a spirobifluorene skeleton [2,2′,7,7′-tetrakis(7-tert-butyl-1-pyrenyl)-9,9′- spirobi[9H-fluorene; 4-PySBF]. The use of spirobifluorene prevents fluorescence quenching by intramolecular energy transfer and/or electron transfer among the chromophores in the excited state. The emission spectra of 4-PySBF exhibited a red shift of 20 nm in comparison to a model compound [9,9′-dioctyl-2,7-bis(7-tert-butyl-1-pyrenyl)- 9H-fluorene; 2-PyF], but its UV-Vis spectrum remained unchanged. Keywords: Spirobifluorene; pyrene; fluorescence; π-conjugation; dye Introduction Recently, blue emitting dyes with high efficiency (Φ ≈ 1.0, log ε 4.5) [1] have been attracting considerable attention because of their applicability to molecular electronic materials such as organic field effect transistors (OFETs) and orga