Luminescent MOFs for selective sensing of Ag and other ions (Fe() and Cr()) in aqueous solution

Two new title MOFs, [Zn(BTA) 2 ] n ( LMOF- 1 ) and [Zn 3 (BTA) 2 (5-tbuip) 2 ] n ( LMOF- 2 ) (BTA = 1 H -benzotriazole, 5-tbuip = 5- tert -butylisophthalic acid), have been synthesized by a solvothermal method. The structures of the two complexes have been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction (PXRD) and thermogravimetric (TG) analysis. And the calculation of PLATON displays that the porosity values are 15.04% and 18.77%. Fluorescence analysis reveals that the two MOFs generate strong blue luminescence; LMOF- 1 and LMOF- 2 can be regarded as multiresponsive fluorescence sensors for Fe( iii ) and Cr( vi ) (CrO 4 2− /Cr 2 O 7 2− ions) detection with high sensitivity and selectivity and a low detection limit in water via fluorescence quenching. It is worth noting that most LMOFs for detecting Ag + to date are mainly formed with rare earth lanthanide metals, while there are still few Zn-based LMOF probes used in Ag + detection. LMOF- 1 can detect trace Ag + in water with a low detection limit. In addition, LMOF- 1 has excellent water stability and thermal stability, and is an excellent material for detecting Ag + in daily water samples. Two metal-organic frameworks, [Zn(BTA) 2 ] n ( LMOF- 1 ), [Zn 3 (BTA) 2 (5-tbuip) 2 ] n ( LMOF- 2 ) (BTA = 1 H -benzotriazole, 5-tbuip = 5- tert -butylisophthalic acid) have been solvothermally synthesized. They show strong blue luminescence and LMOF- 1 shows unusually detecting behavior to Ag + .