氨基酸侧基对Cu(Ⅱ)-L-氨基酸配合物结构特征的影响

The Effects of Side Chains from Ligands on the Structural Characteristic of Copper(Ⅱ) of L-Amino Acids

以 L-缬氨酸和 L-谷氨酸作为配体与 Cu( )配位络合形成二 -L-缬氨酸一水合铜 ( ) (1 )和聚 -L-谷氨酸一水合铜 ( ) (2 )两个配合物 .在配合物 (1 )的结构中 ,两个 L-缬氨酸分子中的氨基氮原子和羧基氧原子以顺位方式与 Cu( )形成螯合的五元环 ,形成的配合物分子间通过氢键构建成右螺旋链状和三维的超分子结构 .在配合物 (2 )中 ,L-谷氨酸分子以羧基氧原子和氨基氮原子与 Cu( )形成螯合五元环 ,并通过 α-羧基氧原子的 μ2 -桥连形成一维右旋链状结构 ,通过 ω-羧基氧原子的桥连形成三维结构的高聚物 .讨论了氨基酸侧基的空间效应和配位能力对配合物结构的影响 .

Two Cu(Ⅱ) complexes of L amino acids, Cu(L valine) 2(H 2O) (1) and [Cu(L glutamic acid)(H 2O)] ∞ (2), have been synthesized and characterized by X ray diffraction. In the structure of complex (1), two L valine molecules chelated with Cu(Ⅱ) in five member ring by the coordination of amino nitrogen atom and carboxylate oxygen atom with the center ion. The molecules of complex (1) construct a right hand helical chain and three dimensional stacking supramolecular structures through hydrogen bonds. In the structure of complex (2), one molecule of L glutamic acid chelated Cu(Ⅱ) by the coordination of amino nitrogen atom and carboxylate oxygen with the ion, one dimensional right hand helical chains and three dimensional polymer are formed through the bridging of μ 2 α carboxyl and ω carboxylate oxygen atom, respectively. The effects of steric hindrance and coordination capability from side chains of ligands on the structural characteristic of Cu(Ⅱ) of L amino acids has been discussed in this paper.