Synthesis and electroluminescent properties of bis(3-N-ethylcarbazolyl)cyanoterephthalidene

A new blue electroluminescent material analog to poly(3,6-N-2-ethplhexylcar bazolyl cyanotere-phthalidene) (PECCP) was synthesized by a facile reaction of 9-ethyl-3 -carbazole carboxy aldehyde with 1,4-phenylenediacetonitrile. The re suiting bis(3-N-ethylcarbazolyl)cyanoterephthalidene (BECCP) having cyano (electron acceptor part) and carbazole moiety (electron donor part) was characterized by NMR, IR, UV and was vacuum-deposited into thin film of smooth surface. BECCP shows blue PL and EL spectra at 480 nm corresponding to 2.58 eV and typical rectifying diode characteristics in ITO/BECCP/Al de vices in both forward and reverse bias. The turn on voltage are +8 V and 4 V when the BECCP layer are 600 and 300 Angstrom thick, respectively. (C) 20 00 Elsevier Science S.A, Ail rights reserved.