A symmetrical azo-based fluorophore and the derived salen multipurpose framework for emissive layers.

The development of new organic simple and low-cost fluorophores is a current topic. To date innovative solutions include azo dyes because of the unique absorption behavior, but the azo group gives poor luminophores in the solid state. In order to produce a luminescent azo dye, we synthesized compound A2 , 4,4′-((1,1′)-(2,5-dimethoxy-1,4-phenylene)bis(diazene-2,1-diyl))dianiline, and its symmetrical Schiff-base derivative C2. The new compound C2 is a weakly luminescent fluorophore in the crystalline phase and when employed as building blocks in self-assembly of zinc (II) coordination polymer. Nevertheless, if used as a dopant in PS and PVK, C2 shows enhanced fluorescence and represents a good on-off naked-eye switch when dispersed in a room-temperature nematic polymer. PL azo dyes are very rare. We produced the symmetrical azo fluorophore C2 with considerable PL performances. The new fluorophore C2 is a yellow emitter weakly fluorescent in the crystalline phase but remarkably luminescent as a dopant in PS, PVK and in a LC matrix for on-off naked-eye PL switch. Unlabelled Image • A fluorescent azo dye employable for optical and electrooptical devices was synthetized. • Azobenzene fluorophores are investigated as emitters for LEDs and OLEDs. • The dye was employed as dopant in polymer matrixes and in the preparation of a zinc coordination polymer. [ABSTRACT FROM AUTHOR]