Hydrothermal Synthesis, Structure, Properties Of Complexes Of 5-Ethyl-3-Pyridinecarboxylate Uranyl (Manganese) Using Imizethapyr As Precursor

Two complexes were synthesized using hydrothermal reaction of imizethapyrwith uranyl or manganese. Their crystal structures, fluorescence and dielectricproperties were determined. The crystal data for complex C₁₆H₁₆UN₂O₆: crystalsystem monoclinic, space group P2₁/c, a=12.965(3)(?), b=10.363(2)(?), c=12.644(2)(?),α=90°,γ=90°,β=94.242(2)°, Z=4. In C₁₆H₁₆UN₂O₆, the EPC(5-ethyl-3-pyridinecarboxylate) molecules, which was disassembled fromimazethapyr, coordinate the uranyl ion. The local coordination environment around Ucenter can be described as an eight-coordinate tetragonal antiprismatic polyhedron.Uranyl cation is two-capped on the equatorial plane composed of four O atoms fromtwo carboxylate groups and two N atoms from two pyridyl group. ComplexC₃₂H₃₂Mn₂N₄O₉ crystallizes in monoclinic system, space group C2/c,a=17.114(2)(?), b=14.5172(19)(?), c=15.473(3)(?),α=90°,β=122.3400(10)°,γ=90°, Z=4. In C₃₂H₃₂Mn₂N₄O₉, Mn²⁺ ion coordinate with six EPC molecules bytwo nitrogen atoms from. two pyridine groups and four oxygen atoms from fourcarboxylate groups and possesses a disorted octahedron.The dielectric constants of all complexes increased with temperature rising, andthe increase rate all increased with the increase of temperature and the decrease ofelectric field frequency. The constant of first complex reached over one hundred attemperature of 350K, and then diminished gradually. Consequently, the dieletric lossof both two complexes also increased with temperature rising. The dieletric loss ofthe first complex showed maximum value at 350K, however, the second complexkeeped on increasing.Strong green fluorescence was observed for uranyl complex under radiation of420nm light. However, no fluorescence was observed for manganese complex.