Unusual Hybrid Materials Prepared by the Oxidation of a Ketone

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• 作者：Daniel L. Holden ; Helen V. Goulding ; John Bacsa ; Neil G. Berry ; Nicholas Greeves ; Richard A. Stephenson ; Ross W. Harrington ; William Clegg ; Andrew M. Fogg
• 刊名：Crystal Growth & Design
• 出版年：2011
• 出版时间：July 6, 2011
• 年：2011
• 卷：11
• 期：7
• 页码：3013-3019
• 全文大小：1001K
• 年卷期：v.11,no.7(July 6, 2011)
• ISSN：1528-7505

文摘

Four new layered phases have been synthesized by the hydrothermal reactions of zinc and magnesium salts with fenbufen (纬-oxo-(1,1鈥?biphenyl)-4-butanoic acid) as a result of the oxidation of fenbufen at the ketone forming biphenylcarboxylate. Reactions with zinc nitrate give different degrees of oxidation, yielding Zn(C₁₆H₁₃O₃)(C₁₃H₉O₂)(H₂O) (1) and Zn₅(OH)₆(C₁₃H₉O₂)₄ (2), depending on the reaction temperature. Compound 2 has an unusual zinc hydroxide layer structure which contains hydroxide-centered Zn₄OH(OH)₄ units where the central hydroxide has two long and two short bonds to the Zn atoms. The mechanism for the ketone oxidation has been investigated by a series of DFT calculations which indicate that a concerted, metal-mediated pathway is lower in energy than a two-step process. The importance of the metal cation in this oxidation reaction has been shown by demonstrating that oxidation of fenbufen also occurs during reactions with magnesium nitrate and zinc chloride. These reactions yielded fully oxidized Mg(C₁₃H₉O₂)₂(H₂O)₂ (3) and half-oxidized Zn(C₁₆H₁₃O₃)(C₁₃H₉O₂)(H₂O) (4), a polymorph of 1. Reactions with ammonium salts gave only recrystallized fenbufen, providing further evidence for the role of the metal cation in these oxidation reactions.