Two robust zinc(II) complexes as multi-functional luminescence sensor for detection of Fe3+, Cr2O72−, and CrO42− ions in water

Two new zinc(II) complexes, namely, [Zn(BBOP)(TPA)0.5]n (1) and [Zn(BBOP)(NDC)·H2O]n (2) (H2TPA = terephthalic acid, H2NDC = 1,4-naphthalene dicarboxylic acid, BBOP = 1,3-bis(benzimidazol-2-yl)-2-oxapropane) are hydrothermally synthesized and characterized. 1 features a 3D 2-fold interpenetrated 3-connected SrSi2-type framework. 2 is a mononuclear Zn(II) complex and further extend into the 3D supramolecular framework by OH⋯O and NH⋯O hydrogen bonding interactions. 1 and 2 both manifest high chemical stability. Two luminescence complexes are excellent sensors for the luminescent detection of Fe3+, Cr2O72−, and CrO42− ions in an aqueous medium. The quenching mechanism of the complexes is also investigated.