Synthesis and characterization Novel sulfonyl-containing fluorenes as materials for organic light-emitting diods

Abstract

Fluorenes and their derivatives based on 2,7-disubstituted-9,9-dialkylfluorene as light-emitting diodes because of the high photoluminescent quantum efficiencies and thermal stabilities. The prepared compounds were characterized by FT-IR, H1NMR, C13NMR, MS, and UV/vis spectroscopy besides the melting points and C.H.N analysis. Key words: flourenes, and light emitting diods.Introduction It is well-known that substituted poly (2,7-fluorene) derivatives are attractive as active components of organic light-emitting diodes due to their thermal and chemical stability and their high emission quantum yields.1-3 Small molecule organic light-emitting diodes are prepared by the consecutive vacuum-evaporation of several organic layers, where each layer fulfils a specific function such as charge injection, charge transport, or emission of light. By optimizing the properties of these layers, highly efficient small molecule organic light-emitting diodes have been prepared.4 Light-emitting diodes electrophosphorescent at room temperature can be fabricated by processing the materials from solution. 5 The electrophosphorescont polymer based efficiency is limited by hole current and unbalanced in the polymer host as in poly light-emitting diodes polymer light-emitting diodes. 6,7 Their chemical synthesis, photophysics, and material properties are of interest not only as an academic curiosity but also as a commercial reality.8,9