Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
Inorg Chem. 2010 Dec 20;49(24):11449-62. doi: 10.1021/ic1013945. Epub 2010 Nov 17.
Co(II) and Zn(II) ions exhibit variable reactivity toward O-containing ligands in aqueous media, affording isolable materials with distinct solid-state lattice properties. d-(-)-quinic acid is a cellular α-hydroxycarboxylate metal ion binder, which reacts with Co(II) and Zn(II) under pH-specific hydrothermal conditions, leading to the isolation of two new species Co(2)(C(7)H(11)O(6))(4)·nH(2)O (1) and Zn(3)(C(7)H(11)O(6))(6)·nH(2)O (2). Compound 1 was characterized by elemental analysis, spectroscopic techniques (FT-IR, UV-visible, EPR), magnetic studies, and X-ray crystallography. Compound 2 was characterized by elemental analysis, spectroscopic techniques (FT-IR, ESI-MS), and X-ray crystallography. The 2D molecular lattices in 1 and 2 reveal the presence of octahedral M(II) units bound exclusively to quinate in a distinct fashion, thereby projecting a unique chemical reactivity in each investigated system. The magnetic susceptibility and solid-state/frozen solution EPR data on 1 support the presence of a high-spin octahedral Co(II) in an oxygen environment, having a ground state with an effective spin of S = 1/2. Concurrent aqueous speciation studies on the binary Zn(II)-quinate system unravel the nature and properties of species arising from Zn(II)-quinate interactions as a function of pH and molar ratio. The physicochemical profiles of 1 and 2, in the solid state and in solution, earmark the importance of (a) select synthetic hydrothermal reactivity conditions, affording new well-defined lattice dimensionality and nuclearity M(II)-quinate materials, (b) structural speciation approaches delineating solid state-aqueous solution correlations in the binary M(II)-quinate systems, and (c) pH-specific chemical reactivity in binary M(II)-quinate systems reflecting structurally unique associations of simple aqueous complexes into distinctly assembled 2D crystalline lattices.
Co(II) 和 Zn(II) 离子在水介质中对含 O 配体表现出可变的反应性，提供具有独特固态晶格性质的可分离材料。d-(-)-奎宁酸是一种细胞 α-羟基羧酸金属离子配体，它在特定 pH 值的水热条件下与 Co(II) 和 Zn(II) 反应，导致两种新物质的分离Co(2)(C(7)H(11)O(6))(4)·nH(2)O (1) 和Zn(3)(C(7)H(11)O(6))(6)·nH(2)O (2)。化合物 1 通过元素分析、光谱技术（FT-IR、UV-可见、EPR）、磁性研究和 X 射线晶体学进行了表征。化合物 2 通过元素分析、光谱技术（FT-IR、ESI-MS）和 X 射线晶体学进行了表征。1 和 2 的 2D 分子晶格揭示了仅以独特方式与奎宁酸结合的八面体 M(II)单元的存在，从而在每个研究系统中呈现出独特的化学反应性。1 的磁化率和固态/冷冻溶液 EPR 数据支持在含氧环境中存在高自旋八面体 Co(II)，其基态具有有效自旋 S = 1/2。二元 Zn(II)-奎宁酸体系的同时水相配位研究揭示了 Zn(II)-奎宁酸相互作用产生的物种的性质和特性，作为 pH 和摩尔比的函数。1 和 2 的物理化学特性，无论是在固态还是在溶液中，都突出了(a)选择合适的合成水热反应条件的重要性，这些条件提供了新的、定义明确的维度和核性 M(II)-奎宁酸材料，(b)结构配位方法，描绘了二元 M(II)-奎宁酸体系中固态-溶液相关性，以及(c)二元 M(II)-奎宁酸体系中特定 pH 值的化学反应性，反映了简单水相配合物结构独特的组合成明显组装的 2D 结晶晶格。
