Dual functional fluorosensors based on flexible bis(pyridylbenzimidazole) derivatives with highly selective and sensitive detection of acetylacetone and Fe3+ ions

Highlights: • Two novel Zn(II)/Cd(II) coordination polymers were synthesized and characterized. • The compounds displayed high thermostability and pH stability (3~12). • 1 and 2 possessed selective and sensitive sensing for ACAC/Fe³⁺ with low detection limit. • 1/2 were the first luminous CPs based on L ligand in sensing ACAC and Fe³⁺ ions. Two novel Zn(II)/Cd(II) coordination polymers (CPs), {[Zn(L)(DCTP)]·H₂O}_n (1) and [Cd₂(L)(DCTP)₂]_n (2) (H₂DCTP=2,5-dichloroterephthalic acid, L=1,3-bis(1-(pyridin-3-ylmethyl)-1H-benzo[d]imidazole-2-yl)propane) were successfully synthesized and characterized. The structure of 1 was formed by a 1D V-like chains and further packed a 2D supramolecular network through hydrogen bonding interactions. The structure of 2 featured an uncommon 3D lattice with the Schläfli symbol of {4.6².7².8}{4.6².7³}₂{4².6².7.8}. 1 and 2 displayed high thermostability and water-stability (pH=3–12). Furthermore, based on luminescence quenching, both CPs 1 and 2 are the first report of fluorescent CPs from L ligand for the detection of acetylacetone and Fe³⁺ ions, with the merits of great efficiency, anti-interference and recyclability abilities.