Redetermination of Ce[B5O8(OH)(H2O)]NO3·2H2O

• Published in: Acta crystallographica. Section E, Structure reports online Structure reports online, 2012-05, Vol.68 (Pt 5), p.i33-i34
• Main Authors: Sun, Wei, Zhu, Teng-Teng, Zhao, Biao-Chun, Huang, Ya-Xi, Mi, Jin-Xiao
• Format: Article
• Language: English
• Subjects: Inorganic Papers
• ISSN: 1600-5368
• DOI: 10.1107/S1600536812016169

The crystal structure of Ce[B 5 O 8 (OH)(H 2 O)]NO 3 ·2H 2 O, cerium(III) aqua­hydroxidoocta­oxidopenta­borate nitrate dihydrate, has been redetermined from single-crystal X-ray diffraction data. In contrast to the previous determination [Li et al. (2003 ▶ ). Chem. Mater. 15 , 2253–2260], the present study reveals the location of all H atoms, slightly different fundamental building blocks (FBBs) of the polyborate anions, more reasonable displacement ellipsoids for all non-H atoms, as well as a model without disorder of the nitrate anion. The crystal structure is built from corrugated polyborate layers parallel to (010). These layers, consisting of [B 5 O 8 (OH)(H 2 O)] 2− anions as FBBs, stack along [010] and are linked by Ce 3+ ions, which exhibit a distorted CeO 10 coordination sphere. The layers are additionally stabilized via O—H⋯O hydrogen bonds between water mol­ecules and nitrate anions, located at the inter­layer space. The [BO 3 (H 2 O)]-group shows a [3 + 1] coordination and is considerably distorted from a tetra­hedral configuration. Bond-valence-sum calculation shows that the valence sum of boron is only 2.63 valence units (v.u.) when the contribution of the water mol­ecule (0.49 v.u.) is neglected.