Properties and Crystal Structure of catena-Poly[praseodymium(III)-hexaaqua-L-threonineK3O,O'O'']trichloride and catena-Poly(pentaaqua-L-threonine-K3O,O',O'') Europium(III) and Ytterbium(III) trichlorides

New complexes of L-threonine and lanthanides(III) of the formulae: [Pr(L-thr)(H2O)6]Cl3 and {Ln(L-thr)(H2O)5]Cl3, where Ln is Eu(III) and Yb(III), where obtained. They were characterized by elemental, thermal and spectroscopic analyses, as well as the crystal structures were determined by X-ray diffraction method. The compounds are stable up to about 363 K but further further heating leads to decomposition to oxychlorides and next to oxides.