Metal-Organic Coordination Complexes Based On Flexible Aromatic Multi-Carboxylic Acid Ligands:Syntheses, Crrstal Structures And Properties

In recent years, novel metal-organic frameworks (MOFs) as functional materials have attracted extensive attention not only due to their intriguing topologies and various structures, but also owing to their potential applications in the fields of catalysis, gas storage and separation, drug delivery, ion exchange, proton conduction, photoluminescence and magnetism, etc. Organic linkers play a very important role in designing and synthesizing MOFs. In this work, we report the synthesis, crystal structures, EA, PXRD, IR, thermal properties and luminescent properties of partial coordination polymers with the semirigid bridging ligands 3,4-bis(carboxymethoxy) benzoic acid (H3bcba) and 4,4-(1,4-phenylenedioxy)dibenzoic acid (H2pdda) as the major organic linkers,3,5-bis (4-pyridyl)-1,2,4-triazolyl (Hbpt) and 4,4’-bipyridine (4,4’-bipy) as the second organic rods, containing different 1D to 3D structures.1. Under the hydrothermal synthesis conditions, we have successfully obtained eight different coordination complexes with H3bcba ligand, containing seven structures formulated as:[Sr3(bcba)2(H2O)3]n (1)[Sr(Hbcba)(H2O)3]n (2)[Zn(Hbcba)(H2O)2]n (3)[Zn3(bcba)2(Hbpt)2 (H2O)2]n (4)[Zn3(bcba)2(4,4’-bipy)2]n-nH2O (5)[Ln(bcba)(H2O)]n-nH2O (Ln=Eu, Nd) (6-7)[Mn(Hbcba)(H2O)3]n-nH2O (8)2. Under the hydrothermal synthesis condition, using the H2pdda ligand as the first organic linker and N-donor auxiliary 4,4’-bipy to design MOFs with Zn2+ ion, thus we have got one novel complex with 3D nework, named:[Zn3(pdda)3(4,4’-bipy)]n (9).To sum up, in hydrothermal synthesis condition, we have gained several novel metal-organic aromatic carboxylic acid coordination complexes with different dimensions in a successful manner. Herein, we describe synthesis methods, structures and the fluorescence properties of some complexes in solid state at room temperature, and other properties. Our work have not only enrich the structures and types of MOFs, as well as provide the necessary experimental data for studying their synthesized laws and properties.