Imidazole-based zinc(II) complexes: Highly selective fluorescent probes for acetone detection

Two Zn-II coordination polymers (Zn-CPs), [Zn(dib)(CH3COO)(2)]center dot 2H(2)O (1) and Zn-3(tib)(2)Cl-6 (2), have been prepared under hydrothermal condition by reactions of 1,4-di(1H-imidazol-1-yl)benzene (dib), or 1,3,5-tri(1H-imidazol-1-yl)benzene (tib) with corresponding Zn-II ions, respectively. Single crystal structure analysis reveals that 1 contains one-dimensional chains, which are further connected into a three-dimensional network by hydrogen bonds and pi...pi interactions. Compound 2 adopts a three-dimensional (3D) supramolecular network which is constructed by one-dimensional (1D) chain via weak Van der Waals force based on Zn(II) ions and tib ligands. These compounds are further characterized by powder X-ray diffraction, element analyses, and photoluminescent spectroscopy. The luminescent properties of 1 and 2 dispersed in different solvents have been investigated systematically. Both of them exhibit a solvent-dependence luminescent behavior and high sensitivity for acetone detection via a fluorescence quenching mechanism. (C) 2014 Elsevier B.V. All rights reserved.