Synthesis and Properties of 9,9 '-Diarylspriofluorene with Substituted Group at 2,7-Position of Fluorene

A series of novel 2-/2,7-((di)arylfluorene building-blocks were synthesized and utilized to prepare novel organic blue-emitting oligomers via Suzuki reaction and Friedel-Crafts reaction. The desired oligomers contained the 4-methyltriphenylamine core and fluorene derivatives peripheries. Their structures were confirmed by NMR and MS techniques and elemental analysis. The maximum photoluminescence (PL) emission wavelengths of the compounds ranged from 442 to 466 nm. Cyclic voltammetry (CV) showed that the highest occupied molecular orbital (HOMO) energy level of the compounds was located between -5.15 and -5.19 eV. The results of differential scanning calorimeter (DSC) and thermogravimetric (TG) indicated that these materials had excellent thermal stability with glass transition temperature of higher than 166 degrees C and thermal-decomposition temperature over 398 degrees C.