Hydrothermal syntheses, structures and properties of five rare earth coordination polymers with (1,3,4-thiadiazole-2,5-diyldithio)diacetic acid

Abstract

Hydrothermal reactions of rare earth ions(III) with a flexible building unit (1,3,4-thiadiazole-2,5-diyldithio)diacetic acid (H 2tzda) lead to five novel coordination polymers with 1D chain and 3D network structures, namely, {[Y 2(tzda) 3(H 2O) 10] · 5H 2O} n ( 1) and [Ln 2(tzda) 3(H 2O) 5] n [Ln = Er ( 2), Pr ( 3), Nd ( 4), Eu ( 5)]. Compound 1 has one-dimensional ribbon-like chain structure constructed by [Y 2(tzda) 3] units through the syn– anti bidentate bridging mode of carboxylate groups. Compounds 2– 5 possess compact three-dimensional network structures which are made up of [Ln 2(tzda) 3] (Ln = Er, Pr, Nd and Eu) units bridged by carboxylate groups. In these compounds, the flexible tzda 2− ligand is versatile and displays six different coordination fashions to meet the requirement of the coordination preference of the metal center. Furthermore, the magnetic behaviors for 2– 5 in the temperature range of 5.0–300 K and photoluminescent property of 5 are significantly investigated in this paper.