Structures and luminescent properties of Sm(III) and Dy(III) coordination polymers with 2,4,6-pyridinetricarboxylic acid

Two rare earth coordination compounds with 2,4,6-pyridinetricarboxylic acid (H₃pta) have been synthesized by the hydrothermal method; the formula is {RE(pta)(H₂O)₃]?·?H₂O} _n RE?=?Sm (1) and Dy (2)]. Complexes 1 and 2 are crystallized in the monoclinic crystal system with P2₁/c space group. X-ray structure analyses show the two complexes have the same structure. Each pta^3? connects three rare earth ions. Both the Sm(III) and Dy(III) complexes exhibit characteristic luminescence in the visible region upon excitation with UV-rays.