Constructions And Properties Of Coordination Polymers Based On Pyridylbenzimidazole Ligands

Coordination polymers（CPs）as new materials have aroused great interest in the field of materials science.The use of CPs as luminescent sensors for the detection of heavy metal ions and organic molecules in wastewater has been the current research central issue.Cd^IIand Zn^II are commonly used d¹⁰ metal ions to construct CPs with luminescent characteristics.The strong conjugated structure on the benzene/naphthalene ring in aromatic carboxylic acids can construct CPs with ideal luminescent characteristics.In addition,the adjunction of pyridine groups can not only increase the coordination sites of N-containing ligands,but also increase supramolecular recognition sites,and it is easy to form structurally stable CPs.Using 1,3-bis（1-（pyridin-4-ylmethyl）-1H-benzoimidazol-2-yl）propane（L1）,1,4-bis（1-（pyridin-4-ylmethyl）-1H-benzoimidazol-2-yl）butane（L2）,1,5-bis（1-（pyridin-4-ylmethyl）-1H-benzoimidazol-2-yl）pentane（L3）,1,6-bis（1-（pyridin-4-ylmethyl）-1H-benzoimidazol-2-yl）hexane（L4）,1,4-bis（1-（pyridin-4-ylmethyl）-1H-benzoimidazol-2-yl）cyclohexane（L5）and1,4-bis（1-（pyridin-4-ylmethyl）-1H-benzoimidazol-2-ylmethyl）benzene（L6）supplemented with four aromatic carboxylic acids as well as Cd^II and Zn^II for ternary compounding to construct twelve novel CPs.1,6,9,12 are 3D（3,3,4,5）,（3,3,4,4,4）,（3,4,4,4,5,5）and（4,4）-connected new topological structures;11 is a 2D（4,4,4）-connected new topological structure;4,5,10 are2D 3,4L13,4,4,4L10 and sql layered structures;2,3,7,8 are 3D gra,sqc6,4,4,4,6,6T3,and dmc frames.1,4～12 show high chemical stability,and can be used as highly selective and sensitive fluorescent sensors to detect pollutants in aqueous solutions.1 can detect acetylacetone/Cr₂O₇^2?with detection limits of 0.876 and 1.99μM;4～7 can be used to detect acetylacetone/Fe³⁺with detection limits of 0.101,0.165,0.193,0.138μM and 6.35,5.01,7.01,6.19μM;8～10 can detect benzaldehyde/Mn O₄^?,the detection limits are 0.037,0.034,0.017μM and 0.449,0.286,0.507μM;11 and 12 can detect ascorbic acid,and the detection limits are 1.42 and 1.54μM.Figure 111;Table 15;Reference 61...