Metal chelation versus internal hydrogen bonding of the .alpha.-hydroxy carboxylate group
作者:H. L. Carrell、Jenny P. Glusker、Elizabeth A. Piercy、William C. Stallings、David E. Zacharias、R. Lindsay Davis、Charles Astbury、Colin H. L. Kennard
DOI:10.1021/ja00260a019
日期:1987.12
hydrogen atom is available for hydrogen bonding, as in potassium 3-fluorodeoxycitrate, where the hydroxyl group is replaced by fluorine, the metal spans the α-fluoro carboxylate group so that the carbon-bound fluorine is part of the coordination sphere of the metal ion. This analysis involved crystal structure analyses by X-ray and neutron diffraction of tripotassium citrate monohydrate with unit cell
本研究分析了 α-羟基羧酸盐基团的金属螯合以及某些碱金属柠檬酸盐中羟基被氟取代的影响。柠檬酸钾一水合物的结构表明,与柠檬酸钠或许多其他盐的情况不同,金属离子不跨越 α-羟基羧酸盐基团。在这种情况下,对于游离柠檬酸,来自羟基的氢原子与中心羧酸酯基团的氧原子形成氢键。当没有这样的羟基氢原子可用于氢键合时,如在 3-氟脱氧柠檬酸钾中,羟基被氟取代,金属跨越 α-氟羧酸盐基团,因此碳键合的氟是配位球的一部分的金属离子。该分析涉及通过 X 射线和中子衍射对具有晶胞尺寸 a = 13.795 (1), b = 11.772 (1), c = 7.092 (2) A 的柠檬酸三钾一水合物进行晶体结构分析;β = 112.57 (2)°;空间群 P2/a。此外,对一水合 3-氟-3-脱氧柠檬酸钾进行了 X 射线衍射研究,晶胞尺寸 a = 8.062 (2), b = 10.215 (1), c = 6.832