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] center dot 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 pta3- 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.