Kumar Abhishek, Semwal Shrivats, Choudhury Joyanta
Organometallics & Smart Materials Laboratory, Department of Chemistry, Indian Institute of, Science Education and Research Bhopal, Bhopal, 462066, India.
Chemistry. 2021 Apr 1;27(19):5842-5857. doi: 10.1002/chem.202004499. Epub 2021 Jan 28.
The "hydricity" of a species refers to its hydride-donor ability. Similar to how the pK is useful for determining the extent of dissociation of an acid, the hydricity plays a vital role in understanding hydride-transfer reactions. A large number of transition-metal-catalyzed processes involve the hydride-transfer reaction as a key step. Among these, two key reactions-proton reduction to evolve H and hydride transfer to CO to generate formate/formic acid-represent a promising solution to build a sustainable and fossil-fuel-free energy economy. Therefore, it is imperative to develop an in-depth relationship between the hydricity of transition-metal hydrides and its influencing factors, so that efficient and suitable hydride-transfer catalysts can be designed. Moreover, such profound knowledge can also help in improving existing catalysts, in terms of their efficiency and working mechanism. With this broad aim in mind, some important research has been explored in this area in recent times. This Minireview emphasizes the conceptual approaches developed thus far, to tune and apply the hydricity parameter of transition-metal hydrides for efficient H evolution and CO reduction/hydrogenation catalysis focusing on the guiding principles for future research in this direction.
某一物种的“氢化物给予能力”指的是其作为氢化物供体的能力。与pK用于确定酸的解离程度类似，氢化物给予能力在理解氢化物转移反应中起着至关重要的作用。大量过渡金属催化的过程都涉及氢化物转移反应这一关键步骤。其中，两个关键反应——质子还原生成氢气以及氢化物转移至一氧化碳生成甲酸盐/甲酸——代表了构建可持续且无化石燃料的能源经济的一种有前景的解决方案。因此，有必要深入研究过渡金属氢化物的氢化物给予能力与其影响因素之间的关系，以便设计出高效且合适的氢化物转移催化剂。此外，这种深入的认识在提高现有催化剂的效率和工作机制方面也会有所帮助。出于这一广泛目标，近期在该领域已开展了一些重要研究。本综述强调了迄今为止所开发的概念方法，即调整和应用过渡金属氢化物的氢化物给予能力参数以实现高效析氢以及一氧化碳还原/加氢催化，并着重阐述了该方向未来研究的指导原则。
