Crystal structure of poly[μ3-acetato-di­aqua-μ3-sulfato-cerium(III)]: serendipitous synthesis of a layered coordination polymer exhibiting inter­layer O—H⋯O hydrogen bonding

Abstract

In the crystal structure of the title compound, the Ce^III cations are ninefold coordinated and linked into chains via the acetate anions and are further connected into layers by the sulfate dianions.

Single crystals of the title compound, [Ce(CH₃COO)(SO₄)(H₂O)₂]_n, were obtained serendipitously by the reaction of Ce(NO₃)₃·6H₂O with 2,5-thio­phenedi­carb­oxy­lic acid (H₂TDC) and acetic acid in a mixture of ethanol and water, where it is assumed that the sulfate ions leached from the Teflon reactor, which was treated with per­oxy­monosulfuric acid prior to its use. Its asymmetric unit consists of one Ce^III cation, one sulfate dianion, one acetate anion and two crystallographically independent water mol­ecules, all of them located in general positions. The cerium cations are coordinated by three acetate anions (one O,O-chelating) and three sulfate dianions that are related by symmetry as well as two independent water mol­ecules within an irregular CeO₉ coordination geometry. The Ce^III cations are linked by the acetate ions into [010] chains, which are further connected into (001) layers by the sulfate dianions. Intra­layer and inter­layer O—H⋯O hydrogen bonds are observed. Powder X-ray diffraction shows that only traces of the title compound have formed together with a large amount of an unknown crystalline phase. Attempts to prepare the title compound in larger amounts and as a pure phase were unsuccessful.