A new water-stable cadmium(II) coordination polymer for luminescence sensing of chlortetracycline and Fe³⁺ ions in aqueous solution

A new ternary coordination polymer (CP), {[Cd(L)(nip)(H₂O)]·H₂O}_n (1) (L = 1,6-bis(benzimidazol-2-yl)hexane, H₂nip = 5-nitroisophthalic acid), was hydrothermally synthesized and characterized. 1 is a two-dimensional sheet and extends into three-dimensional supramolecular networks through O-H···O hydrogen bonding interactions, which displays high thermal and pH stabilities. 1 demonstrated notable selectivity, sensitivity, and reusability for the luminescent sensing of chlortetracycline (CTC) and Fe³⁺ ions. Density functional theory calculations and UV−Vis absorption spectroscopy were employed to investigate the possible sensing mechanisms.

A new Cd(II) metal coordination polymer, namely {[Cd(L)(nip)(H₂O)]·H₂O}_n can act as a sensitive luminescent probe for chlortetracycline (CTC) and Fe³⁺ ions in water with excellent selectivity and recyclability.