Benedict Jason B, Bullard Theresa, Kaminsky Werner, Kahr Bart
Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
Acta Crystallogr C. 2004 Nov;60(Pt 11):m551-3. doi: 10.1107/S0108270104019043. Epub 2004 Oct 9.
The title compound, K(+).(C(8)H(5)O(4))(2)H.2H(2)O or K(+).C(16)H(11)O(8)(-).2H(2)O, was prepared by slow evaporation of an aqueous solution of potassium hydrogen phthalate. The molecular complex consists of a potassium cation coordinated to a proton-bound hydrogen phthalate dimer and two water molecules. The potassium cation resides on a twofold axis in a distorted square-antiprism coordination geometry. The compound is isomorphous with the ammonium analogue, previously misidentified. As potassium hydrogen phthalate is frequently used in the manufacture of buffers, organic carbon standards, acidimetric standards and various other products, the crystallization of a compound with a different stoichiometery from a solution containing the acidimetric standard has important practical implications.
标题化合物K⁺·[(C₈H₅O₄)₂H]⁻·2H₂O或K⁺·C₁₆H₁₁O₈⁻·2H₂O是通过邻苯二甲酸氢钾水溶液的缓慢蒸发制备的。分子配合物由一个与质子结合的邻苯二甲酸氢盐二聚体和两个水分子配位的钾阳离子组成。钾阳离子位于一个双重轴上，具有扭曲的四方反棱柱配位几何结构。该化合物与之前被错误鉴定的铵类似物同构。由于邻苯二甲酸氢钾常用于制造缓冲剂、有机碳标准品、酸碱滴定标准品及各种其他产品，从含有酸碱滴定标准品的溶液中结晶出具有不同化学计量比的化合物具有重要的实际意义。
