Synthesis And Properties Of Organic-inorganic Hybrid Based On Bis-benzimidazole

In order to synthesize organic and inorganic hybrid materials with excellent adsorption properties,this paper used 2,6-bisbenzimidazole pyridine（L）and acid as organic raw materials and studied the appropriate condition to form organic-inorganic hybrid gel in the absence and presence of Zn（Ⅱ）/Ni（Ⅱ）perchlorate.Through studying the intermolecular interactions of forming gel and verifying dye adsorption factors of some ingredients from gel material,this paper not only illustrated the relationship between molecular structure and the adsorptive property but also laid a foundation for obtaining the specific adsorbing materials.The main research was as follows:In this paper,2,6-bis（2-benzimidazyl）pyridine and squaric acid were used as ligands（L）,metal perchlorate as a template in solvent DMF to form organic-inorganic hybrid gel（GLs）.The GLs have been characterized by IR,optical microscopy,SEM and TEM.And chemical stimulus response,rheological property and dye absorption capability of GLs were tested.The results showed that L reacted with Zn（Ⅱ）in DMF to generate gels.After adding squaric acid,the mechanical strength and rigidity of the gel increased significantly.Under the light microscope,the shape of sample was needle,but it showed different forms under the TEM and SEM.Compared with the reticular fiber and clusters,the gel with chain network structure and fiber morphology had better mechanical and dye adsorption performance.The adsorption experiment toward dye methyl orange showed that the adsorption quantity of the gel was in the range of 12.15-15.38 mg.g-1.Based on the above results,the formation mechanism of the gel was proposed from the structures of ligand,squaric acid and metal ions..To illustrate the potential molecular structure of the gel material,2,6-diphenylimidazole and 1 equivalent of square acid were refluxed in ethanol to form product.Supramolecular complex was obtained from a mixture of squaric acid and 2,6-diphenylimidazole in deuterated dimethylsulfoxide（d-DMSO）and characterized by single-crystal X-ray diffraction.The data showed that supramolecular complex was a one-dimensional chain polymer by π-π stacking and intermolecular hydrogen bond.And the influence of different temperature and CCl₄ concentrations on the hydrogen bond in polymer was investigated.Moreover,the hydrogen bond was further evaluated by density functional theory（DFT）and atoms in molecules（AIM）theory.The calculated result of hydrogen bonding energy were 135.65 and 49.40 J·mol-1,respectively.In the process of research on dye absorption of gel material,it was found that perchlorate had good adsorption for methylene.In order to understand the active principle of perchlorate,the samples formed by the absorption of perchlorate toward dyes were characterized by XPS,XRD and pH.Through the comparative experiments with other metal salts,the mechanism adsorption of methylene was explored.Dynamic adsorption experiments between perchlorate and methylene blue were tested to study the effects of time and the adsorption quantity on the adsorption rate.And the result was compared with the static adsorption.It showed that the static adsorption was mainly blue solid precipitation produced by perchlorate ions and methylene blue,and adsorption was based on complexation,metal salt and acidity in dynamic experiments.The researches provided the fundamental theory to design new materials.Meanwhile,it also strongly proved the adsorption mechanism of gel material.