| From the organic– inorganic supramolecular clan ,we know that carboxylic acid ligands are better organic bridging ligand due to the rich diversity coordination mode with metal ions to build into an organic - metal supramolecular coordination polymers , which supramolecular coordination compounds tend to have a novel topology and broad application prospects, and its catalysis, superconductivity, medicine, new materials, and many a relatively wide range of uses, therefore carboxylic acid coordination polymers become the hot spots that people study in recent years .Coordination polymers are formed by transition metal and organic ligands self-assembly, and we can get the desired structure and properties of supramolecular coordination polymers through the experimental design and the self- assembling. Through the experiments ,Our lab team members show that the factors that affect the molecular self-assembly are many, such as an organic module structure, transition metal ion coordination geometries, hydrogen bonding andπ-πinteraction between conjugate, reaction solvent and reaction conditions have a significant impact on the self-assembly of coordination polymers, but the final results show that the choice of ligand is the most important factor. In this paper, I adopt new organic ligand 2, 2 ', 3, 3'-azobenzene-4-carboxylic acid (A `B` T `C`) and 3, 3', 4, 4'- azobenzene-4-carboxylic acid (ABTC) (Figure 1 and 2) synthesized by our laboratory team members, and the second ligand-phenanthroline (phen) with the transition metal to synthesize five coordination polymer crystals which have not been reported and their crystal structure were characterized through X-ray diffraction. Ligand 2, 2 ', 3, 3'-azobenzene-4-carboxylic acid and 3, 3', 4, 4'-azobenzene-4-carboxylic acid make the performance of the planar structure because of the azo bond and the role of benzene conjugated.Two ligands is a steel skeleton of the organic ligand, thus building a skeleton for the compounds are very important. The major findings are as follows:[Ni2 (C16H10N2O8) (phen)2 (H2O)4]·4H2O 1[Zn2 (C16H10N2O8) (phen)2 (H2O)6]·4H2O 2[Zn2 (C16H10N2O8)2 (phen)2 (H2O)8]·3H2O 3[Mn2 (C16H10N2O8)2 (phen)2 (H2O)8]·3H2O 4[Co2 (C16H10N2O8) ( phen)2 (H2O)3]·2H2O 51.In aqueous solution conditions we successfully synthesized supramolecular coordination polymer 1 Includeing the new synthetic ligand 2,2`, 3,3` - azobenzene-4-carboxylic acid (A `B` T `C`),Ni metal ion and the second ligand phen ,which is one-dimensional step-like structure .By the major organic modules A `B` T `C`, phen, and Ni ions ,supramolecular coordination polymer 1 is builded into the octahedral organic - compounds of metal skeleton. All the Ni atoms are connected through phen and 2, 2 ', 3, 3'-azo-benzoic 4 acid to form a complex 1-D step-like structure.First phen and Ni atoms, as well as the main module of organic ligand A `B` T `C` are connected to form for a 1-D chain structure of the steps,and then through molecular hydrogen bonding of water molecules and the molecules A `B `T` C `,the connection of this 1-D chain structure constitutes a 3-D network topology.2.By new synthetic ligand of steel 3, 3 ', 4, 4'-azobenzene 4 acid (ABTC) and the metal ions Zn, Mn, Co in aqueous solution conditions,we successful synthesis four super-molecule polymer 2,3, 4,5.By hydrogen bonds 2 and 3 are builded into three-dimensional layered structure with organic ligands ABTC and metallic Zn .By hydrogen bonds and the role of benzene ring plane conjugated,complex 4 is builded into three-dimensional network structure with the ABTC and the transition metal Mn. Through the ABTC and the transition metal Co atoms gh hydrogen bonds complex 5 is builded into three-dimensional network topology .
|
PDF Full Text Request