...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Zeitschrift fur Anorganische und Allgemeine Chemie >Modification of a Hexadentate Amine based Ligand System by N-Methylation and Effects on Spin State and Redox Behavior of the Corresponding Transition Metal Complexes
【24h】

Modification of a Hexadentate Amine based Ligand System by N-Methylation and Effects on Spin State and Redox Behavior of the Corresponding Transition Metal Complexes

机译：N-甲基化改性六齿胺基配体系统及其对相应过渡金属配合物的自旋态和氧化还原行为的影响

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

Recently, the synthesis of hexadentate ligands based on N,N'-bis-(2,2'-bipyridine-6-ylmethyl)-2,2'-biphenylenediamine (1a-d) and the corresponding iron(II) complexes (3a-d) was reported by our group. In this contribution we present the synthesis of the analogous cobalt(II) complexes 4a-d. Together with the iron(II) complex the electrochemical behavior of the complexes 3 and 4 was investigated by cyclic voltammetry (CV). The aminomethyl substructure was identified as the main source of ligand degradation caused by chemical oxidation with air. Upon exposure to air the amine group in complexes 3 and 4 is oxidized to imine and even amide groups. Some examples (8, 9) of the oxidation products were characterized by X-ray structure analysis. In order to increase the robustness of the Fe~(II) and Co~(II) complexes towards oxidation, the ligand scaffold of 1a was modified by N-methylation of the amino group yielding the tertiary amine 2. The corresponding iron(II) and cobalt(II) complexes employing 2 as ligand were synthesized {[Fe(2)][PF_6]_2 (5), [Co(2)][PF_6]_2 (6)} and fully characterized, their redox behavior and spin-state was investigated by CV and Evans' method. It was found, that the introduced N-methyl group leads to a substantial anodic shift of the M~(II)-M~(III) redox potential and the stabilization of Fe~(II) and Co~(II) high-spin state. By means of X-ray structure analysis these effects could be explained by repulsive steric effects of the methyl group.
机译：最近，基于N，N'-双-（2,2'-联吡啶-6-基甲基）-2,2'-联苯二胺（1a-d）和相应的铁（II）配合物的六齿配体的合成（3a -d）由我们小组报告。在这一贡献中，我们提出了类似的钴（II）配合物4a-d的合成。通过循环伏安法（CV）研究了配合物3和4与铁（II）的电化学行为。氨甲基亚结构被确定为由空气化学氧化引起的配体降解的主要来源。暴露于空气中后，配合物3和4中的胺基被氧化为亚胺甚至酰胺基。通过X射线结构分析表征了氧化产物的一些实施例（8、9）。为了提高Fe〜（II）和Co〜（II）配合物对氧化的耐受性，通过氨基的N-甲基化修饰了1a的配体骨架，得到了叔胺2。相应的铁（II）和钴（II）配合物以2为配体合成{[Fe（2）] [PF_6] _2（5），[Co（2）] [PF_6] _2（6）}并充分表征，它们的氧化还原行为和自旋-状态通过CV和Evans方法研究。结果发现，引入的N-甲基导致M〜（II）-M〜（III）氧化还原电位发生明显的阳极移位，并稳定了Fe〜（II）和Co〜（II）高自旋州。通过X射线结构分析，这些作用可以通过甲基的排斥性空间作用来解释。

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