(Acetato‐κ2O,O′)dihydroxidoytterbium(III) hemihydrate

The title compound, Yb(C₂H₃O₂)(OH)₂]·0.5H₂O, was obtained via hydrothermal reaction of Yb(CH₃COO)₃·H₂O with NaOH at 443 K. The compound forms two‐dimensional layers with six crystallographically independent Yb^III atoms. Four of these form YbO₈ coordination polyhedra, while the coordination number of the remaining two Yb^III atoms is 7. Five of these coordination polyhedra are interconnected mainly via hydroxide groups, as they build a narrow inner layer that extends infinitely within the ab plane. The sixth Yb^III atom resides outside this inner layer and builds a terminal YbO₈ coordination polyhedron on the layer surface. Its coordination environment comprises four carboxylate O atoms belonging to three different acetate entities, three hydroxide groups and one water molecule. Adjacent layers experience weak interactions via hydrogen bonds. The Yb—O distances lie in the range 2.232 (4)–2.613 (5) Å.