Two metal-organic frameworks based on phenylenediacetate and N,N′-Bis-pyridin-3-ylmethylene-hydrazine used as multi-responsive luminescent sensors for Fe3+, CrO42− and Cr2O72− in aqueous solution

Abstract Two novel metal-organic frameworks (MOFs), namely, [Ni(3-bpmh)(HEA)·2H2O]n (1) and [Zn(3-bpmh)(HEA)·H2O]n (2) (3-bpmh=1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene, o-H2HEA=1,2-phenylenediacetic acid), respectively, were hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction analysis, elemental analysis, infrared spectroscopy and thermogravimetric analysis. Single crystal structures revealed that 1 and 2 were two-dimensional structure and two-dimensional (4,4)-topological layer structure respectively. In addition, compound 2 had a selective sensing effect on ions. Therefore, it was possible to detect Cr2O72−, CrO42− and Fe3+ ions by fluorescence quenching.