Redox-active ligands and their coordination complexes

氧化还原活性配体及其配位化合物

• 批准号: RGPIN-2014-05388
• 负责人: Hicks, Robin
• 金额: $ 3.93万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=653545
• 关键词: Redox; active; ligands; their; coordination

Compounds based on the transition metals are used in an incredibly broad spectrum of applications. They are used as reagents and as catalysts to make new drugs, polymers, and other important classes of chemicals. They also possess physical properties (light absorption, emission, magnetism.) that are exploited in many high-tech applications ranging from MRI to batteries to alternative energy. Whatever the particular application, chemists typically work to tailor the properties of metal complexes by carefully selecting the ligands (or designing new ones) that are bound to the metal. The idea of "ligand design" is endemic to many, many aspects of transition metal chemistry.**By and large these efforts are based on the premise that the properties of metal complexes stem principally from the metal, and the ligands play a supporting role in fine tuning these properties. An alternative approach involves using ligand which themselves have some active function. The ligand property of interest in my research program is redox activity. As their name suggests, "redox-active ligands" (RALs) can be oxidized or reduced analogously to many transition metals. These sorts of ligands have been known for about 50 years but until recently the main focus was on simply trying to understand the electronic structure of RAL complexes. **In the past decade there has been growing recognition that RAL complexes could possess very useful applications: Several technologically important physical properties (optical, magnetic, molecular switching) stem from ligand-based redox activity. And the possibility of harnessing ligand-centered redox activity to make new/more effective/cheaper reagents and catalysts is beginning to receive worldwide attention. These general ideas are still in early stages of exploration; more work is needed to determine the potential uses of RAL complexes.**This proposal outlines research into the synthesis, properties and uses of RAL complexes based on new kinds of redox-active ligands. Other researchers in this field are focusing on well-established types of RALs; my goals are to try to broaden the "RAL toolkit" by developing non-traditional systems under development in my lab. We have discovered two fundamentally new types of redox-active ligand, one based on a class of stable radical and the other based on an industrially important organic dye. Both are straightforward to make, and both have unusual/distinctive properties which can be modulated through conventional substituent effects. The proposed research is principally discovery-oriented, in that we will examine a range of properties for our RAL complexes. This work involves a lot of chemical synthesis (designing and making target molecules, based on hypotheses of what they might "do"). In some cases the "property" is reactivity/catalysis, whereas in others the focus is on electro/optical properties. We will assess the strengths and weaknesses of our systems in relation to other RAL complexes (and more generally, other metal complexes not based on RALs) and in so doing we hope to (i) contribute to the collective understanding of the fundamental nature of redox-active ligands and (ii) identify new opportunities for development in catalysis and/or advanced materials.

基于过渡金属的化合物有着极其广泛的应用。它们被用作试剂和催化剂来制造新药、聚合物和其他重要化学品。 它们还具有物理特性（光吸收、发射、磁性），可用于从 MRI 到电池再到替代能源的许多高科技应用。 无论具体应用是什么，化学家通常都会通过仔细选择与金属结合的配体（或设计新的配体）来调整金属配合物的性能。 “配体设计”的想法是过渡金属化学的许多方面所特有的。**总的来说，这些努力都是基于这样的前提：金属络合物的性质主要源于金属，而配体起着支持作用微调这些属性。另一种方法涉及使用本身具有某些活性功能的配体。我的研究项目中感兴趣的配体特性是氧化还原活性。顾名思义，“氧化还原活性配体”（RAL）可以像许多过渡金属一样被氧化或还原。此类配体为人所知已有大约 50 年，但直到最近，人们的主要关注点还只是试图了解 RAL 配合物的电子结构。 **在过去的十年中，人们越来越认识到 RAL 复合物可能具有非常有用的应用：几个技术上重要的物理特性（光学、磁性、分子开关）源于基于配体的氧化还原活性。利用以配体为中心的氧化还原活性来制造新的/更有效的/更便宜的试剂和催化剂的可能性开始受到全世界的关注。这些总体想法仍处于探索的早期阶段；需要做更多的工作来确定 RAL 配合物的潜在用途。**该提案概述了基于新型氧化还原活性配体的 RAL 配合物的合成、性质和用途的研究。该领域的其他研究人员正在关注成熟的 RAL 类型；我的目标是通过开发我实验室正在开发的非传统系统来尝试扩大“RAL 工具包”。我们发现了两种全新类型的氧化还原活性配体，一种基于一类稳定自由基，另一种基于工业上重要的有机染料。两者制作起来都很简单，并且都具有不寻常/独特的特性，可以通过传统的取代基效应进行调节。拟议的研究主要以发现为导向，我们将检查 RAL 复合物的一系列特性。这项工作涉及大量的化学合成（根据目标分子可能“做什么”的假设来设计和制造）。 在某些情况下，“性质”是反应性/催化性，而在其他情况下，重点是电/光性质。我们将评估我们的系统相对于其他 RAL 配合物（更一般地说，其他不基于 RAL 的金属配合物）的优势和劣势，通过这样做，我们希望 (i) 促进对氧化还原基本性质的集体理解-活性配体和（ii）确定催化和/或先进材料发展的新机会。