The Synthesis and Electroluminescence Properties of 4-Benzofuranyl-1,8-Naphthalimide Derivatives

Abstract

A series of fluorescence compounds, 4-benzofuranyl-1,8-naphthalimides, were prepared through cycloaddition reaction from 4-ethynyl-1,8-naphthalimides and o-iodophenols which catalyzed by a Pd(PPh3)2Cl2 / CuI system under mild conditions. The intermediate material, 4-ethynyl-1,8- naphthalimide, was synthesized from 4-bromo-1,8- naphthalimide and trimethylsilyl- acetylene. The absorption and fluorescence spectra of 4-benzofuranyl-1,8- naphthalimides were studied and the quantum yields were measured. The maximum UV/vis absorption spectra were in the range of 375-400 nm and the maximum emission spectra were in the range of 470-510 nm. The electro- luminescent properties were also mensurated through a doped electroluminescent device which contains 1% 1,8-naphthalimides and 99% CBP (4,4'-N,N'-dicarbazole-biphenyl), It’s shown the maximum brightness reached 3700 cd/ m2 at 22.5V.