Novel 5-oxazolone derivatives containing an N-phenyl-aza-15-crown-5 moiety were synthesized for the first time. The structures of the new derivatives were confirmed by H-1 NMR, C-13 NMR and FT-IR. In addition, evaluation of the visible absorption and emission properties of the structures were carried out in eight different solvents. The products show intense visible absorption maxima in the range 467-524 nm, and fluoresced strongly, with emission maxima from 496 to 689 nm in all the solvents tested. (c) 2007 Elsevier Ltd. All rights reserved.