Alfred Werner 在近 100 年前提出,二次配位层在决定过渡金属配合物的物理性质方面发挥着重要作用。我们现在知道,二级配位层几乎影响过渡金属化学的所有方面,包括金属介导过程中的反应性和选择性。这些特征在过渡金属配合物对分子氧的结合和活化中得到了突出体现。二级配位层的控制与金属配合物(1)可逆地结合分子氧或(2)结合并活化分子氧形成高反应性金属-氧配合物的能力之间存在明显的联系。在这篇论坛文章中,从结构与功能关系的角度提出并讨论了几个生物和合成的例子。特别强调具有确定的非共价相互作用的系统,例如涉及双氧衍生配体的分子内氢键。为了进一步说明这些效应,描述了具有碱性氧配体的金属-氧配合物对CH键的均裂。
Alfred Werner 在近 100 年前提出,二次配位层在决定过渡金属配合物的物理性质方面发挥着重要作用。我们现在知道,二级配位层几乎影响过渡金属化学的所有方面,包括金属介导过程中的反应性和选择性。这些特征在过渡金属配合物对分子氧的结合和活化中得到了突出体现。二级配位层的控制与金属配合物(1)可逆地结合分子氧或(2)结合并活化分子氧形成高反应性金属-氧配合物的能力之间存在明显的联系。在这篇论坛文章中,从结构与功能关系的角度提出并讨论了几个生物和合成的例子。特别强调具有确定的非共价相互作用的系统,例如涉及双氧衍生配体的分子内氢键。为了进一步说明这些效应,描述了具有碱性氧配体的金属-氧配合物对CH键的均裂。
Nickel(II) complexes stabilized by bis[N-(6-pivalamido-2-pyridylmethyl)]benzylamine: Synthesis and characterization of complexes stabilized by a hydrogen bonding network
作者:Darla A. Powell-Jia、Melinda T.-N. Pham、Joseph W. Ziller、A.S. Borovik
DOI:10.1016/j.ica.2010.05.006
日期:2010.10
Intramolecular hydrogen bonds in metalloproteins are key in directing reactivity yet these effects have been difficult to achieved in synthetic systems. We have been developing a synthetic system that uses hydrogen-bonding interactions to modulate the secondary coordination around a transition metal ion. This was accomplished with the ligand bis[N-(6-pivalamido-2-pyridylmethyl)] benzylamine (H(2)pmb), which contains two carboxyamido units appended from pyridine rings. Several nickel complexes were prepared and structurally characterized. In particular, we found that the appended carboxyamido groups either provide intramolecular H-bond donors or can be converted to bind directly to a metal center. We established that the complex Ni(II)H(2)pmb(Cl)(2) can be sequentially deprotonated with potassium tert-butoxide, causing coordination of the carboxyamido oxygen atoms and concomitant loss of the chloro ligands. The chloro ligands were also removed with silver(I) salts in the presence of acetate ions and the complex Ni(II)H(2)pmb(kappa(2)-OAc)(kappa(1)-OAc) was isolated, in which an intramolecular H-bonding network occurs between the H(2)pmb ligand and the coordinate acetato ligands. (C) 2010 Elsevier B.V. All rights reserved.