...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Dalton transactions: An international journal of inorganic chemistry >Copper(II) and zinc(II) ion binding properties of a MAP type branched ligand with histidines as surface functionalities
【24h】

Copper(II) and zinc(II) ion binding properties of a MAP type branched ligand with histidines as surface functionalities

机译：以组氨酸为表面官能团的MAP型分支配体的铜（II）和锌（II）离子结合特性

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A novel branched peptide type ligand consisting of three lysines as branching units and four histidines as functional groups has been designed and prepared by solid phase peptide synthesis. The N-terminal histidines offer eight primary protonation/metal ion binding sites: four amino and four imidazole groups, capable of binding up to two metal ions. We examined the protonation equilibria, and the complex formation processes with copper(II) and zinc(II) ions in c_M : c_L = 1 : 1 and 2 : 1 initial concentration ratio in aqueous solutions. The composition, speciation and the solution structure of the complexes have been determined by combined pH-potentiometric titrations, visible absorption, circular dichroism and NMR spectroscopy. In the case of both metal ions, mono- and dimetallic complexes formed with bis-histamine type coordination as the main species. While above pH 8 the precipitation of a neutral complex was observed for both metal ions, in the copper(II) containing systems it dissolved in alkaline solutions (pH > 11.0). The resulting complex in an equimolar system displays deprotonated amide-nitrogen coordination, with fused five-membered chelate rings around the metal ion in [CuLH_(-3)]~-. At the same time, only one copper(II) is able to coordinate in the same manner in the [Cu_2LH_(-5)]~- species. The second metal ion is probably surrounded by two amide nitrogens and two others either from amino or imidazole donor groups.
机译：通过固相肽合成，设计并制备了由三个赖氨酸作为分支单元和四个组氨酸作为官能团的新型分支肽型配体。 N-末端组氨酸提供八个主要的质子/金属离子结合位点：四个氨基和四个咪唑基团，最多可以结合两个金属离子。我们检查了质子平衡，以及水溶液中c_M：c_L = 1：1和2：1初始浓度比下铜（II）和锌（II）离子的络合物形成过程。配合物的pH电位滴定，可见光吸收，圆二色性和NMR光谱测定了配合物的组成，形态和溶液结构。就两种金属离子而言，主要形成双-双胺型配位的单金属和双金属络合物。在高于pH 8时，观察到两种金属离子均出现中性络合物沉淀，但在含铜（II）的体系中，它溶解在碱性溶液中（pH> 11.0）。在等摩尔体系中生成的络合物显示出去质子化的酰胺-氮配位，在[CuLH _（-3）]〜-的金属离子周围带有稠合的五元螯合环。同时，[Cu_2LH _（-5）]〜-物种中只有一种铜（II）能以相同的方式配位。第二种金属离子可能被两个酰胺氮和另外两个氨基或咪唑供体基团包围。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号