Synthesis and luminescent properties of novel soluble quinacridones

Some novel 2, 5, 9, 12- tetra-substituted quinacridones were synthesized. The comparison of absorption spectra and fluorescence spectra of these soluble quinacridones between in solutions and in solid film indicated that the formation of intermolecular hydrogen bonds in the crystalline was obstructed by N-alkylation. These compounds have good solubility in common solvents such as dichloromethane, chloroform, acetone, DMF etc. The good solubility provides an opportunity for a higher doping concentration of the quinacridone fluorophore chromophore in the application of photoelectronic devices. The longer fluorescence lifetimes (ca. 20 ns) of these soluble quinacridones were measured by single-photon counting technique, which seems to be hopeful for the luminescence application. The EL device made with the soluble quinacridone show a luminance of 150 cd/m(2) and injected current as high as 400 mA/cm(2) at 18 V.