One Cd-II-MOF as a multi-responsive fluorescent probe for sensing Fe(III) and Cr(VI)

One metal-organic framework [Cd-3(L)(2)(H2O)9]center dot 9H(2)O (MOF 1), where H3L=5-(((4-carboxyphenyl)oxy)methyl) benzene-1,3-dicarboxylic acid, has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, and elemental analysis. MOF 1 exhibits a 2D microporous structure with an accessible volume of 22.4%. Luminescent property studies reveal that MOF 1 can act as a promising luminescent sensor for detecting Fe(III) and Cr(VI) with high selectivities and low detection limits, which are additionally free from the interference of other ions. Moreover, the mechanism of selective quenching was studied by measuring the UV-Vis absorption of the host metal-organic framework and the target analyte ions. The fluorescence resonance energy transfer is the possible mechanism involved in the quenching of the fluorescence intensity.