Dinuclear Calcium Complexes with Intramolecularly NH.O Hydrogen-Bonded Dicarboxylate Ligands.
Dinuclear Calcium Complexes with Intramolecularly NH.O Hydrogen-Bonded Dicarboxylate Ligands.
复制标题
具有分子内 NH.O 氢键二羧酸配体的双核钙配合物。
DOI：
10.1021/ic981055t
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发表时间：
1999
影响因子：
4.6
通讯作者：
A. Nakamura
中科院分区：
文献类型：
--
作者：
N. Ueyama;Jiro Takeda;Yusuke Yamada;A. Onoda;Taka;A. Nakamura
合成了一个新的双核钙配合物[Ca（2）{（2-OCO-3-CH（3）C（6）H（3）NHCO）（2）C（CH（3））（2）}（2）（CH（3）OH）（6）]（1），作为嗜热菌蛋白酶双钙结合位点8配位Ca（II）离子的结构模型。该配合物在酰胺NH和羧酸根氧阴离子之间有四个NH·O氢键。两种类型的桥接协调的羧酸配体钙（II）被发现在1。酰胺NH与两个羧酸根氧的阴离子氧形成强NH.O氢键。双核钙配合物与8个等摩尔量的2，4，6-三甲基苯甲酸或2-CH（3）-6-t-BuCONHC（6）H（3）COOH之间的配体交换反应表明NH·O氢键阻止了Ca-O键的解离。
A novel dinuclear calcium complex, [Ca(2){(2-OCO-3-CH(3)C(6)H(3)NHCO)(2)C(CH(3))(2)}(2)(CH(3)OH)(6)] (1), was synthesized as a structural model of 8-coordinated Ca(II) ions in the double calcium-binding site of thermolysin. The complex has four NH.O hydrogen bonds between the amide NH and the carboxylate oxygen anion. Two types of bridging coordination of the carboxylate ligand to Ca(II) were found in 1. The amide NH forms a strong NH.O hydrogen bond with the anionic oxygen of the two carboxylate oxygens. A ligand-exchange reaction between the dinuclear calcium complex and eight equimolar amounts of 2,4,6-trimethylbenzoic acid or 2-CH(3)-6-t-BuCONHC(6)H(3)COOH indicates that the NH.O hydrogen bond prevents the dissociation of the Ca-O bond.