TIPA-ligand-based luminescent Cd(II) organic frameworks as an outstanding sensor for detecting Fe³⁺ in an aqueous medium

Two new title MOFs, namely [Cd₂(TIPA)₂(bpodc)₂]_n (1 or MOF-1), [Cd₂(TIPA)₂(oba)₂]_n (2 or MOF-2) (TIPA = tris(4-(1H-imidazol-1-yl)phenyl)amine, bpodc = benzophenone-4,4′-dicarboxylic acid, oba = 4,4′-oxydibenzoic acid), have been synthesized via a solvothermal method. MOF-1 and MOF-2 both have a 2-fold interpenetrating 3D framework, and the calculation of PLATON display that porosity are 18.6% and 19.5%, respectively. Attributing to MOF-2's uncoordinated carboxylate groups, it exhibits a high sensitivity in detecting Fe³⁺ with a very large quenching coefficient K_sv up to 27 027 M⁻¹. Moreover, MOF-2 also has potential applications in chemical sensing of CrO₄²⁻ and Cr₂O₇²⁻.