Exploring Hydrogen-Atom- and Hydride-Transfer Non-Innocent Ligands

在这项由美国国家科学基金会化学部化学结构、动态和机理B计划资助的项目中，加州大学欧文分校化学系的艾伦·F·海杜克教授正在开发一种新的配体，用于开发催化反应。该研究计划的主要目标是了解实现氢原子和氢化物转移反应的基本配体性质，以便设计新的配位络合物作为催化剂，用于精细和商品化学合成中的重要还原反应，以及一氧化碳和二氧化碳等丰富的化学原料的循环利用。该项目的基本性质是有机、有机金属和无机化学的交界点，对所有教育水平的化学家都有广泛的吸引力，特别适合高级化学教育。为此，该项目包括一个强有力的组成部分，鼓励代表性不足的群体在STEM研究领域攻读高级学位。氧化还原活性或氧化还原非无害配体平台在无机和有机金属化学中因其能够在简单的配位络合物中产生不确定的电子性质而在无机和有机金属化学中得到广泛应用。这些性质已经被用于多电子反应的催化剂，用于电荷转移的光敏剂，以及具有先进的电和磁性能的材料的合成。本文提出的工作将开发一种新型的非无毒配体，它利用儿茶酚型配体的电子和质子转移能力来实现以配体为中心的氢原子转移(HAT)和氢化物转移(HT)反应。在这个项目中，将研究两个相关的钳形配体，以回答几个具有广泛适用性的基本问题：(A)基于配体的HAT和HT反应的热力学极限是什么？(B)基于配体的HAT和HT反应性的分子水平机制(S)是什么？(C)是否可以使用配体结构和金属离子选择来调整这种基于配体的反应性，以通过操纵热力学或动力学因素来选择性地支持HAT或HT的反应性？该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In this project, funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division of NSF, Professor Alan F. Heyduk of the Department of Chemistry at the University of California, Irvine is developing a new class of ligand for use in the development of catalytic reactions. The principal goal of this research program is to understand the fundamental ligand properties that enable hydrogen-atom and hydride transfer reactivity so new coordination complexes can be designed to serve as catalysts in reduction reactions of importance in fine and commodity chemical synthesis and in the recycling of abundant chemical feedstocks such as carbon monoxide and carbon dioxide. The fundamental nature of the project, which lies at the interface of organic, organometallic and inorganic chemistry, is broadly appealing to chemists at all education levels and is particularly well-suited to advanced levels of chemical education. Towards this end, the project includes a strong component that encourages underrepresented groups to pursue advanced degrees in STEM research areas. Redox-active or redox non-innocent ligand platforms are well established in inorganic and organometallic chemistry for their ability to engender adventitious electronic properties in simple coordination complexes. Such properties have been exploited in catalysts for multi-electron reactivity, in photosensitizers for charge-transfer applications, and in the synthesis of materials with advanced electrical and magnetic properties. The work proposed herein will develop a new type of ligand non-innocence that leverages both electron- and proton-transfer abilities of catecholate-type ligands to achieve ligand-centered hydrogen-atom transfer (HAT) and hydride transfer (HT) reactivity. In this project, two related pincer-type ligands will be examined to answer several fundamental question of broad applicability: (a) What are the thermodynamic limits of ligand-based HAT and HT reactivity? (b) What is (are) the molecular-level mechanism(s) of ligand-based HAT and HT reactivity? (c) Can ligand architecture and metal ion selection be used to tailor this ligand-based reactivity to favor selectively HAT or HT reactivity through the manipulation of thermodynamic or kinetic factors?This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.