Cooperative Reactivity and Catalysis using Abundant Metal Clusters.

使用丰富的金属簇的协同反应和催化。

• 批准号: RGPIN-2019-06978
• 负责人: Johnson, Samuel
• 金额: $ 2.11万
• 依托单位: University of Windsor
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=683041
• 关键词: Cooperative; Reactivity; Catalysis; using; Abundant

Focused efforts towards the design and synthesis of polynuclear transition metal species have intensified in the last decade. In part, these efforts stem from attempts to mimic the difficult multielectron transformations facilitated by polynuclear metalloenzymes. Examples include the Mn-O cofactor in Photosystem II, as well as the carbide bearing [FeMo] cofactor in Nitrogenase. Although a plethora of transition metal clusters have been reported, the majority are highly stable species, due to coordinative saturation and molecular orbital configurations that feature large HOMO/LUMO gaps that arise from commonly used ligands such as CO.***Towards the goal of designing transition metal clusters that have a more reactive nature we are investigating clusters of the late 1st row transition metals that are assembled with inexpensive readily-available ligands that are small enough to permit cluster formation, but large enough to ensure coordinative unsaturation. These complexes behave as a unique and understudied class of clusters, with varied electron counts that deviate from theoretical predictions, low-lying paramagnetic excited states that may allow low barrier reaction pathways, tolerance to a range of functional groups, and a remarkable propensity for cooperative activation of commonly inert C-H, C-C and C-O bonds. The potential of these clusters as unique catalysts for skeletal bond rearrangements is obvious, but as yet insufficient fundamental understanding is a barrier to their application. The short term goals of this project aim to provide a better understanding of the chemistry of the highly reactive late metal clusters like [(iPr3P)Ni]5H6, with long-term goals of extending its capability in cooperative bond activation to catalytic processes. The design of more robust clusters anchored by interstitial atoms, inspired by the carbide centre [FeMo] cofactor, provides a route to cluster design that is fundamentally different from those based strictly on complex ancillary ligand design.********

在过去十年中，加强了设计和合成多核过渡金属物种的重点工作。在某种程度上，这些努力源于试图模拟多核金属酶促进的困难的多电子转化。例子包括光系统II中的锰-氧辅因子，以及固氮酶中含碳化物的[FeMo]辅因子。尽管已经报道了过多的过渡金属簇合物，但大多数是高度稳定的物种，这是因为配位饱和和分子轨道构型具有来自常用配体(如CO)的大HOMO/LUMO间隙。*为了设计具有更具活性性质的过渡金属簇合物的目标，我们正在研究第一排晚期过渡金属簇合物，这些簇合物与廉价的容易获得的配体组装在一起，这些配体足够小，足以形成簇合物，但足够大，以确保配位不饱和。这些络合物表现为一类独特的、未被研究的簇合物，具有偏离理论预测的不同电子计数，可能允许低势垒反应路径的低位顺磁激发态，对一系列官能团的耐受性，以及共同激活通常惰性C-H、C-C和C-O键的显著倾向。这些簇合物作为骨架键重排的独特催化剂的潜力是显而易见的，但尚不充分的基础知识是其应用的障碍。该项目的短期目标是更好地了解[(IPr3P)Ni]5H6等高活性晚期金属簇合物的化学组成，长期目标是将其合作键活化能力扩展到催化过程。在碳化物中心[FeMo]辅因的启发下，由间隙原子锚定的更强健的团簇的设计，提供了一条从根本上不同于那些严格基于复杂辅助配体设计的团簇设计的途径。