A luminescent Cd(II)-based metal−organic framework for detection of Fe(III) ions in aqueous solution.

A novel Cd( (II)-organic framework [Cd(Hcbic)] n (H 3 cbic = 1-(4-carboxybenz-yl)−1H-benzoim-idazole-5, 6-dicarboxylic acid) was assembled and characterized by X-ray single crystal analysis. The Cd-MOF features one-dimensional left and right-handed double helical chains with screw-pitch of about 4.727 Å and the 4-methyl benzoic acid groups of Hcbic 2− ligands in MOF-1 play many ribbons distributing in the two sides of the 2D networks. It is found that MOF-1 shows high selectivity ( K SV = 1.8 × 10 5 L / mol) for Fe 3+ ions in water solution with luminescent quenching because of the existence of uncoordinated carboxyl groups within open frameworks, which indicates that MOF-1 is a simple and reliable detection sensing reagent for Fe 3+ in practical applications. [ABSTRACT FROM AUTHOR]