5-Bromo-3-fluorosalicylaldehyde, CAS number 251300-28-4, is a derivative of salicylaldehyde (2-hydroxybenzaldehyde), bearing functional groups of both bromo- and a fluoro-halogens, a hydroxyl and carboxylic acid around the benzene ring. 5-Bromo-3-fluorosalicylaldehyde is an ideal candidate for synthesizing Schiff base which is a sub-class of imine (ketimines or aldimines). The synthesis of Schiff base starts with nucleophilic addition to the aldehyde with an amine (either aliphatic or aryl) forming a hemiaminal, then followed by dehydration to form the aldimine.
The Schiff bases synthesized from 5-Bromo-3-fluorosalicylaldehyde are bidentate/tetradentate ligands. They can further form coordination complexes that are used as dyes in OLED and dye-sensitized solar cells (DSSCs with power conversion efficiency circa 7.7 %). Such complexes are also investigated in antimicrobial activities against bacteria and fungi.