Organic Nano-sized Pigment Based on Bis(4-(N-(9,9-DiethyI-2- Fluorenyl)Phenylamino)Phenyl)Fumaronitrile as Highly Efficient Red Fluorescence

摘要

Red fluorescence was widely applied in full color organic light-emitting display and anti-counterfeit technology. Due to concentration quenching red fluorescence was weak and even no luminescence in a solution or solid state. Therefore, novel red fluorescent pigment bis(4-(7V-(9, 9-diethyl-2-fluorenyl)phenylamino)phenyl)fumaronitrile (EFPAFN) with non-planar fluorenylamino group and fumaronitrile core was prepared. The compound existed a pair of antiparallel dipole limiting molecular interaction, showed strong red photoluminescence which centralized at 657 nm in solid film. The decomposition temperature of EFPAFN was observed at around 422 °C. In different polarity of solvents the absorption and emission peaks of EFPAFN showed positive and then negative solvatochromic shifts. EFPAFN in water/tetrahydrofuran (v/v, 9:1) mixture was adjusted and aggregated into small size particles in the range of 141-531 nm or big size particles of 255-825 nm as fluorescent organic nanoparticles (FONs). FONs of EFPAFN with donor-acceptor group showed strong emission at 653 nm and had potential applications in nano-sized fluorescence and optoelectronic device.