A New Family of Lanthanide Borate Halides with Unusual Coordination and a New Neodymium-Containing Cationic Framework

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• 作者：Matthew J. Polinski ; Evgeny V. Alekseev ; Victoria R. Darling ; Justin N. Cross ; Wulf Depmeier ; Thomas E. Albrecht-Schmitt
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：February 18, 2013
• 年：2013
• 卷：52
• 期：4
• 页码：1965-1975
• 全文大小：592K
• 年卷期：v.52,no.4(February 18, 2013)
• ISSN：1520-510X

文摘

The reactions of Ln₂O₃/CeO₂/Pr₆O₁₁ (Ln = La鈥揘d, Sm), molten boric acid, and concentrated HBr or HI result in the formation of La[B₇O₁₀(OH)₃(H₂O)Br], Ln[B₆O₉(OH)₂(H₂O)₂Br]路0.5H₂O (Ln = Ce, Pr), Nd₂[B₁₂O_17.5(OH)₅(H₂O)₄Br_1.5]Br_0.5路H₂O (NdBOBr), Sm₄[B₁₈O₂₅(OH)₁₃Br₃], and Ln[B₇O₁₁(OH)(H₂O)₃I] (Ln = La鈥揘d, Sm). The lanthanide(III) centers in these compounds are found with 9-coordinate hula hoop or 10-coordinate capped triangular cupola geometries, where there are six approximately coplanar oxygen donors provided by the polyborate sheet. The sheets are formed into three-dimensional frameworks via BO₃ triangles that are roughly perpendicular to the layers. Additionally, a new cationic framework, NdBOBr, has been isolated. NdBOBr is unusual in that not only is it a cationic framework, but it is also the first trivalent f-element borate to have terminal halides bound exclusively to the base site of the hula hoop. The Ln[B₇O₁₁(OH)(H₂O)₃I] (Ln = La鈥揘d, Sm) structures require two corner-shared BO₃ units in order to tether the layers together because of the large size of the capping iodine atom.