A new fluorescent Cu(I) coordination polymer for selective detection of oxo-anion chromium(VI) in water

Abstract

A new Cu(I)-coordination polymer [Cu2(bpp)2Cl]·Hapta·H2O (1) (H2apta = 4-aminophthalic acid, bpp = 1,2-bis(4-pyridyl)propane)) has been successfully designed and prepared. The crystal structure, C H N analysis, FTIR spectroscopy, XPS and intrinsic photophysical properties of compound 1 were investigated. In 1, two types of Cu(I) ions are separately consolidated by the two types of bidentate bpp ligands to construct a one-dimensional (1D) chain along the b axis. Adjacent 1D chains are further linked by the Cl ligand to induce a final 2D layer structure with a unique crb topology. Notably, the introduced H2apta linker only serve as guest molecule, occupying the space of the channels. More importantly, the fluorescence properties of 1 can be utilized to detect oxoanion Cr(VI) ions with high sensitivity and selectivity in aqueous solution through fluorescence quenching effect. The detection limits of 1 toward Cr2O72−, CrO42− are as low as 5.36 μM and 15.17 μM, respectively. Furthermore, the possible sensing mechanism has also been discussed in more detail.