Synthesis and properties of metal organic framework compounds containing Eu and Tb

Abstract

A series of coordination polymers consisting of lanthanide Ln(III) with Ln = Eu and Tb, pyridine-3,5-dicarboxylate (3,5-dipic) and dimethylformamide (DMF) have been prepared under a solvothermal condition. Single crystal structure determination was succeeded for Tb-compound but not for Eu-compound due to its poor crystallinity. However, the structure of Eu-compound is expected to be slightly different from that of Tb-compound. These compounds consist of three-dimensional networks of Ln(III) coordination polyhedra chains parallel to the ac plane. The Ln(III) coordination polyhedra are cross-linked by two 3,5-dipic molecules to form large hexagonal cages. DMF and H2O molecules exist in these cages. On thermal treatment of Eu-compound and Tb-compound, removal of DMF and H2O molecules from the cages was observed. The thermally treated Tb-compound and Eu-compound had a very large surface area. The thermal stability and fluorescent properties of these compounds are reported.