Synthesis And Properties Of Transition Metal Coordination Polymers Constructed By 2,5-furandicarboxylic Acid

Metal-organic frameworks(MOFs),as an emerging class of porous inorganic-organic hybrid materials, built by coordination bonds between metal ions clusters and multidentate organic ligands which have been recognized as a new class of porous crystalline materials.With highly regular and tunable pore structures,this type of materials exhibits excellent feasibility in diverse applications such as gas and chemical storage,chemical separations,sensing,selective catalysis,ion exchange,and drug delivery.To date,numerous porous MOFs different in framework topological structures and functional properties have been reported.According to the literature,multi-carboxylate ligands have been widely used due to their functional groups.In this regard,furan-2,5-dicarboxylic acid has two carboxylate groups with C2v-like symmetry can be a good candidate for the construction of a variety of coordination polymers.Up to now,a few of MOFs with furan-2,5-dicarboxylic acid have been reported.In this contribution,we report the syntheses of three kinds of MOFs with the transition mental salts and furan-2,5-dicarboxylic acid as the ligand:(HDMA)2·Cd3(FDA)4·DMF,(HDMA)·(HTEA)Mn3(FDA)4 and(HDMA)·Zn3(FDA)4(DMF)2.The three MOFs synthesized by solvothermal synthesis method.All of them contain linear trinuclear SBU and infinite chain along with SBU.In compound(HDMA)2?Cd3(FDA)4?DMF, 7-coordinated Cd vertex-sharingly links 7-coordinated Cd and edge-sharingly links 6-coordinated Cd to linear trinuclear SBU, which is vertex-sharingly linked into infinite chain.In compound(HDMA)?(HTEA)Mn3(FDA)4, three six-coordinated Mn vertex-sharingly link each other into SBU, which is connected by two carboxyls into helical chain of S-configuration. In compound(HDMA)·Zn3(FDA)4(DMF)2 contains two types of Zn centers.Adjacent 2D sheets are connected at the trimeric units from both the sides by a pair of FDA ligands, leading to a 3D framework.Owing to the different metal ions as the nodes.We get some detail information from X-ray single crystal diffraction include the asymmetric unit of the titled compound(HDMA)2?Cd3(FDA)4?DMF is consisted of three cadmium(II) cations, four FDA anions, two protonated HDMA cations and one DMF solvent molecule, dispalying the charged framework. There are three crystallographic independent Cd cations in asymmetric unit. Cd(1) cation is octahedrally coordinated by six monodentate carboxyls of six FDA molecules. Cd(2) and Cd(3) are 7-coordianted by five FDA molecules containing two bidentate carboxyls and three carboxyls, showing pentangle bipyramid geometry. The linear trinuclear SBU(secondary building unit) is connected by vertex-sharing Cd(3)-Cd(1) and edge-sharing Cd(3)-Cd(2). Every linear trinuclear SBU vertex-sharingly connects the neighboring SBU into an infinite chain. Along with Cd infinite chain, four infinite chains and four FDA molecules connect each other to(4,4)-net. The asymmetric unit of(HDMA)·(HTEA)Mn3(FDA)4 composed of three Mn cation, four FDA molecules and one protonated HDMA and one protonated HTEA, showing the charged framework as well. There are three crystallographic independent Mn cations in asymmetric uni. All three Mn cation are octahedrally coordinated. The six ligated oxygen atoms of Mn(1) and Mn(2) arise from four monodentate carboxyls and one bidentate carboxyl. The six ligated oxygen atoms of Mn(3) are offered by six monodentate carboxyls of six FDA molecules. The linear trinuclear SBU is vertex-sharingly arranged. The adjacent SBUs along with infinite chain are linked by two oxygen atoms of carboxyl of FDA molecule which then form a network containing 3-ring and 4-ring.The asymmetric unit of(HDMA)·Zn3(FDA)4(DMF)2 composed of three Zn cation, four FDA molecules and one protonated HDMA and one protonated DMF, showing the charged 3D framework. The asymmetric unit contains two types of Zn centers.The trimeric units are connected by four FDA ligands in bc plane to form a 2D sheet. Adjacent 2D sheets are connected at the trimeric units from both the sides by a pair of FDA ligands, leading to a 3D framework.And on this basis,I also studied the properties of functional group,framework structure,purity,crystallization,thermal stability with IR,XRD,TGA of the three MOFs.