A new porous coordination polymer reveals selective sensing of Fe3+, Cr2O72-, CrO42-, MnO(4)(-)and nitrobenzene, and stimuli-responsive luminescence color conversions

摘要

A novel one-dimensional spiro-like chain coordination polymer with a blue-emission signal was solvothermally synthesizedviathe reaction of Zn(2+)ions with organic ligandHL(4-(4-(2-chloroimidazo[1,2-a]pyridin-3-yl)-[2,3 '-bipyridin]-6-yl)benzoic acid), which is further extended to a porous three-dimensional supramolecular framework, namely, the porous coordination polymer (PCP), [Zn(L)(2)]center dot 2DMF (USTC-5). This PCP was characterized by IR spectroscopy, thermogravimetry, and single-crystal, and powder X-ray diffraction methods.USTC-5possesses larger quasi-hexagonal channels with Lewis-base sites, and is a better CO(2)adsorption or promising CO2/N(2)selective material, suggesting potential application in gas separation.USTC-5also can serve as a multi-responsive sensing material for detecting Fe3+, Cr2O72-, CrO42-, MnO(4)(-)and nitrobenzene (NB). Moreover, the mechanism of the selective luminescence quenching response for Cr2O72-, CrO42-, MnO(4)(-)and NB can be mainly ascribed to the competitive adsorption of excitation wavelength energy betweenUSTC-5and Cr2O72-, CrO42-, MnO(4)(-)or NB; meanwhile, Fe(3+)ions diffused into the channels ofUSTC-5and formed contacts with Lewis-base sites inUSTC-5, leading to luminescence quenching. Significantly,USTC-5displays reversible luminescence color switching in response to acid-base vapor stimuli, which originates from the conversion between the amorphous form and the crystal mediated by protonation-deprotonation processes. Such a stimuli-responsive conversion provides a promising approach to design and construct smart PCP materials.