2,2'-[Benzene-1,2-diylbis(iminomethanediyl)]diphenol derivative bearing two amine and hydroxyl groups as fluorescent receptor for Zinc(II) ion.

A new non-natural receptor 2,2'-[benzene-1,2-diylbis(iminomethanediyl)]diphenol (4) was synthesized, and it is fluorogenic behaviour toward various metal ions were investigated. Receptor 4 exhibited pronounced fluorescence enhancement in the presence of Zn(2+), which can visually be discernible by an orchid fluorescence in compared to other metal ions. The receptor 4 shows high sensitivity and selectivity for Zn(2+) through changes in the fluorescence intensity based on chelation-enhanced fluorescence (CHEF). The binding modes of the complexes were investigated by Job's plot and density functional theory (DFT).