Synthesis And Properties Of Rare Earth Coordination Polymer Based On Aromatic Polycarboxylic Acid

The design and synthesis of metal-organic frameworks (MOFs) have attracted intensive attention in past two decades due to their intriguing network topologies and potential applications as luminescence, gas storage, absorption, catalysis and magnetic materials. In synthesis process of metal-organic frameworks, rare earth elements with high coordination number, flexible modes coordination characteristics and special physical properties of optical, electrical, magnetic, makes it a very valuable metal center. Synthesis process, however, due to factors such as PH, temperature, auxiliary ligand influence of controllable synthesis of coordination compounds is still a huge challenge. In this article, eight complexes were synthesized under hydrothermal conditions and its structure and properties were studied:(1)Yb3+coordination polymer was synthesized. A novel3-D ytterbium coordination polymer,[Yb4(AIP)6(2,2’-bipy)]n (1) has been synthesized by self-assembly of Yb(III) ions,5-aminoisophthalic acid (H2AIP) and2,2’-bipyridine (2,2’-bipy) under hydrothermal condition. The Yb3+ions in coordination polymer has three different coordination modes. Three different coordination modes of Yb3+ions are linked to two different rods building blocks through carboxylic acid. two kinds rods building blocks are connected by b5-aminoisophthalic acid into the three-dimensional structure of coordination polymer. the fluorescence of1properties are analyzed, and compared with the ligand, coordination polymer fluorescence was enhanced.(2) Y3+coordination polymers were synthesized. A novel coordination polymer,[Y(NIPH)(HNIPH)(phen)]n (2) has been synthesized by self-assembly of Y(III) ions,5-Nitroisophthalic acid (NIPH) and1,10-Phenanthroline hydrate (phen) under hydrothermal condition and [YCd2(HNIPH)2.5(N1PH)2(H2O)]n(3) has been synthesized by self-assembly of Y(Ⅲ) ions, Cd ions5-Nitroisophthalic acid (H2NIPH) under hydrothermal condition.(3)Ln3+coordination polymers were synthesized.{[Y(BTEC)(H2BTEC)(H2O)]·5H2O}n (4),[Tb(H2BTEC)(OH)]n (5),{[Y(H2BTEC)(OH)(H2O)4]·H2O·C5H6N2}n (6),{[Tb(H2BTEC)(OH)(H2O)4]·H2O·CsH6N2}n (7) and{[Eu(H2BTEC)(OH)(H2O)4]·H2O·C5H6N2}n(8) have been synthesized by self-assembly of Y(Ⅲ), Tb(Ⅲ), Eu(Ⅲ) ions.1.2,4,5-Benzenetetracarboxylic acid,1,10-Phenanthroline hydrate (phen) and4-Aminopyridine under hydrothermal condition.4,5has three-dimensional structure.6,7,8crystallography isomorphism with one-dimensional structure.7,8has the good green and red fluorescence properties. (4) the luminescence of coordination ploymers were enhanced by doping different ions, complexes2,4,5doped and its fluorescence properties have been characterized. Results show that under appropriate doping ratio, the fluorescence intensity, quantum efficiency and the fluorescence intensity is enhanced.