Two-dimensional rare earth coordination polymers involving different coordination modes of thiodiglycolic acid

Two coordination polymers [La2(tdga)3(H2O)2]n (1) and {[Pr2(tdga)3(H2O)2]·H2O}n (2) were obtained by the reaction between Ln(OH)3 (Ln=La, Pr) and thiodiglycolic acid (H2tdga=H2S(CH2CO2)2), which have a novel double-layered and a single-layered structure, respectively. In the complexes, new coordination modes of the ligand were observed.