A penetrating metal-organic framework based on N-heterocyclic carboxylic acid with sensing properties toward Cr(VI)/Fe(III) and nitrobenzene

A luminescent metal-organic framework, [Cd(tmlb)(bbibp)]_n (1) (H₂tmlb = (1H-1,2,4-triazol-1-yl)methylenebis(benzonic acid), bbibp = bis(benzoimidazo-1-ly)biphenyl), has been solvothermally synthesized and characterized by elemental analysis, infra-red spectroscopy, single-crystal X-ray diffraction, thermogravimetric analysis, and powder X-ray diffraction. Complex 1 exhibits two interpenetrating uninodal 4-connected 3-D frameworks with a (6⁵·8) topology. The luminescence studies reveal that the complex displays sensitive and selective luminescence sensing toward Cr(VI) (CrO₄ ²⁻ and Cr₂O₇ ²⁻) anions, Fe(III) cation, and nitrobenzene. The potential quench mechanism was discussed.