Features of Changes in Composition and Structures of Rare-Earth Halide Complexes with Acethylurea

Structures of rare-earth halide complexes with acetylurea (AcUr), [Sm(AcUr)2(H2O)5]Cl3, [Eu(AcUr)2(H2O)5]Br3·H2O, [Ln(AcUr)2(H2O)4]Br3·H2O (Ln = Tm, Yb), and [Lu(AcUr)(H2O)6]Br3 were determined. Analysis of compositions and structures of these compounds along with the earlier reported analogs allowed us to consider the features of their changes depending on the atomic number of the element. The size of the central atom was found to be the decisive factor.