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Synfacts 2008(3): 0262-0262  
DOI: 10.1055/s-2008-1042711
Synthesis of Materials and Unnatural Products
© Georg Thieme Verlag Stuttgart · New York

Excellent Blue Fluorescent Trispirobifluorenes

Contributor(s):Timothy M. Swager, Kristin L. Glab
S. Yu, H. Lin, Z. Zhao, Z. Wang, P. Lu*
Zhejiang University, Hangzhou, P. R. of China
Excellent Blue Fluorescent Trispirobifluorenes: Synthesis, Optical Properties and Thermal Behaviors
Tetrahedron Lett.  2007,  48:  9112-9115  
Further Information

Publication History

Publication Date:
21 February 2008 (online)

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Key words

spiro compounds - bifluorenes - fluorophores

Significance

Spiro-linked fluorophores exhibit greater morphological stability and more intense fluorescence than their nonspiro-linked parent compounds. The spiro center also tends to reduce intermolecular interactions that lead to a ‘green-emission tail’, which is undesirable for organic light-emitting-device (OLED) applications. Preparation of 9,9′-spirobifluorenes, however, is generally difficult. In this communication, S. Yu et al. synthesized trispirobifluorene 1 by cyclization of 2,7-diiodofluorene with pentaerythritol tetrabromide under basic conditions. Trispirobifluorene 1 was further elaborated by Suzuki or Sonagahira reactions.

Comment

Preliminary studies indicate that compounds 2 and 3 may be good materials for optoelectronic applications. These fluorophores emit at violet to blue regions of the visible spectrum with excellent quantum efficiencies in cyclohexane solution. A ‘green-emission tail’ could not be detected for compounds 2 and 3 annealed in N2 or air. These compounds also showed high thermal stabilities with no weight losses observed below the decomposition temperatures of 277-459 °C.

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