Two new coordination polymers containing 1,4-bis(2-ethylbenzimidazole) as luminescent chemosensors for Fe³⁺ ions and tetracycline

Two new ternary Cd(II) coordination polymers, [Cd-2(L)(tbip)(2)](n) (1) and {[Cd(L)(0.5)(1,4-NDC)]center dot 0.4H(2)O}(n) (2) (H(2)tbip = 5-tert-butylisophthalic acid, 1,4-H2NDC = 1,4-naphthalenedicarboxylic acid and L = 1,4-bis(2-ethylbenzimidazol-1-ylmethyl)benzene), were hydrothermally synthesized and characterized via single-crystal X-ray diffraction, IR spectroscopy, powder X-ray diffraction (PXRD) and thermogravimetric analysis. 1 is a 1-D linear chain, while 2 exhibits a 3-D framework, which can be defined as a 3-D xah (sqc320) topology with the Schlafli symbol of {4(2).6(2).8(2)}{4(6).6(4)}. 1 and 2 remained stable in a pH range of 4.0-13.0 and 3.0-13.0, respectively. 1 and 2 displayed excellent luminescent sensing abilities for Fe3+ ions and tetracycline with high sensitivity and selectivity.