Rational Construction of Two Zn–Organic Frameworks for Selective Luminescent Sensing and Efficient CO₂ Chemical Fixation

Abstract

Through a hydrothermal reaction of 3-(3-carboxylphenyl) isonicotinic acid (H2L) and dipyridyl with Zn­(Ac)2·2H2O, two metal–organic frameworks (MOFs), [Zn­(L)­(bpa)0.5] n (1) and {[Zn­(L)­(bpp)0.5]·H2O} n (2) (bpa = 1,2-bi­(4-pyridyl)­ethane, bpp = 1,3-di­(4-pyridyl)­propane), are prepared. Complexes 1 and 2 have similar twofold interpenetrated three-dimensional (3D) layer-pillared networks. Compounds 1 and 2 exhibit outstanding fluorescence-sensing performances toward Cr2O7 2–, especially, featuring the ratiometric fluorescence against levofloxacin (LEVO) and ciprofloxacin (CIP). To the best of our knowledge, it is the first example of ratiometric detection using antibiotics. The quenching mechanism is mainly attributed to the large area of competitive absorption between the ultraviolet (UV) absorption bands of substances and the excitation peaks of complexes. Furthermore, compounds 1 and 2 could serve as efficient heterogeneous catalysts for the fixation of CO2 with various epoxides benefiting from the presence of unsaturated zinc ions as Lewis acid sites.

An ultra-fast UV-electrochemical sensor based on Cu-MOF for highly sensitive and selective detection of ferric ions

“…17 Most of the UV sensors based on MOFs are used for sensing organic molecular or gas molecules. [18][19][20][21] However, its application to ion sensing is rarely reported. As sensor materials are applied to water systems, MOFs need to simultaneously possess good structural stability, high optical/ electrochemical activity, and superior solvent tolerance.…”