SYNTHESIS AND CHARACTERIZATION OF LUMINESCENT MATERIALS

Abstract

We have successfully synthesized new organic and organometallic luminescent materials which possess moderate thermal stability and may find use in electroluminescent devices. Complexation behavior of bipyridine and terpyridines ligands featuring fluorene in the conjugation chain was investigated. The copper and platinum complexes formed by refluxing anhydrous CuC12 and [Pt(PhCN)2C12] with the ligand in dichloromethane and toluene were characterized by NMR, EPR, electronic spectra, fluorescence spectra and elemental analysis. Platinum complexes emit blue color similar to the free ligand however, the copper(II) complexes of the ligands were found to be nonemissive. Their marked thermal stability makes them valuable materials for organic light emitting diodes. Fused polyaromatic materials comprising indole, quinoxaline and imidazole were also synthesized in good yield and have been characterized by spectroscopic and thermal methods. The parent material 6H-indolo[3,2-b] quinoxaline (IQ) was synthesized by a condensation reaction using isatin and o-phenylene diamine. IQ was N-alkylated with n-butyl bromide. The alkylated indoloquinoxaline was formylated which serves as the starting material for the production of the imidazole tethered indoloquinoxalines. These molecules are suitable for charge transport (hole & electron) in molecular layer. They also possess good thermal stability