Comparative Coordination Chemistry of PNP and SNS Pincer Ruthenium Complexes
Comparative Coordination Chemistry of PNP and SNS Pincer Ruthenium Complexes
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PNP 和 SNS 钳钌配合物的比较配位化学
DOI：
10.1021/acs.organomet.1c00480
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发表时间：
2021
期刊：
影响因子：
2.8
通讯作者：
Bernskoetter, Wesley H.
中科院分区：
文献类型：
--
作者：
Chirdon, Danielle N.;Kelley, Steven P.;Hazari, Nilay;Bernskoetter, Wesley H.
由PNP钳形配体负载的钌羰基配合物是用于一系列氢化和脱氢反应的突出催化剂。最近，钌配合物与更便宜，更空气稳定的SNS钳形配体已经成为有吸引力的替代品，用于开发改进的催化剂。然而，目前缺乏的信息，PNP配体中的膦供体与SNS配体中的硫供体的替代如何影响合成，结构和所得金属络合物的电子性质。在此，一系列钌羰基配合物与SNS钳形配体的配位化学已被系统地与相关的PNP-连接物种进行了比较。研究了三种不同的SNS钳形配体，包括基于吡啶基的NC 5 H3 {CH 2（StBu）} 2配体和两种脂肪族配体HN{CH 2CH 2（StBu）} 2和NCH 3 {CH 2CH 2（StBu）}2，以及沿着的单齿辅助配体的不同组合。的几何结构的SNS和PNP钌配合物进行了研究，使用NMR光谱和X-射线晶体学。此外，这些配合物的氧化还原性能和电子结构的探测通过循环伏安法和DFT计算相结合。总体而言，SNS和PNP络合物之间的差异远远超出了简单地调节对金属的诱导捐赠，并且包括合成结果的变化以及影响氧化还原行为的几何形状的变化。我们的研究揭示了SNS配体的配位化学的基本信息，这可能有助于解释催化结果。
Ruthenium carbonyl complexes supported by PNP pincer ligands are prominent catalysts for a range of hydrogenation and dehydrogenation reactions. Recently, Ru complexes with cheaper, more air stable SNS pincer ligands have emerged as attractive alternatives for the development of improved catalysts. However, there is currently a paucity of information on how the replacement of the phosphine donors in PNP ligands with the sulfur donors in SNS ligands influences the synthesis, structure, and electronic properties of the resulting metal complexes. Herein, the coordination chemistry of a series of Ru carbonyl complexes with SNS pincer ligands has been systematically compared with related PNP-ligated species. Three different SNS pincer ligands were explored including a pyridyl based NC5H3{CH2(StBu)}2ligand and two aliphatic ligands, HN{CH2CH2(StBu)}2and NCH3{CH2CH2(StBu)}2, along with different combinations of monodentate ancillary ligands. The geometric structures of the SNS and PNP Ru complexes were studied using NMR spectroscopy and X-ray crystallography. Additionally, the redox properties and electronic structures of these complexes were probed through a combination of cyclic voltammetry and DFT calculations. Overall, differences between SNS and PNP complexes extend well beyond simply modulating inductive donation to the metal and include changes in synthetic outcomes, as well as variations in geometry that impact redox behavior. Our study reveals fundamental information about the coordination chemistry of the SNS ligand, which may aid in interpreting catalytic results.