Crystal structure and thermal properties of the lanthanum(III) complex with triethylenetetraaminehexaacetic acid:: K3[La(TTHA)]•5H2O

The complex, K3[La(TTHA)]. 5H(2)O, was prepared and its crystal structure was analyzed by single crystal X-ray diffraction method. In the complex, the La(III) ion adopts a ten-coordinate geometry with four nitrogen atoms and six carboxyl oxygen atoms from the same TTHA ligand molecule. Its coordination polyhedron can be described as a distorted bicapped square antiprism. Each [La(TTHA)](3-) anion is linked by K+ cations via carboxyl groups of TTHA ligand to form a three dimensional crystal structure. The thermal properties were investigated by TG and DTA techniques in argon atmosphere. The materials resulting from thermal treatment were La(OH)(3) and K2O which were identified by powder X-ray diffraction technique.