کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1402404 | 1501743 | 2014 | 7 صفحه PDF | دانلود رایگان |
• Explained why thiourea and its derivatives often act as strong electron-donating ligands in palladium-catalyzed reactions.
• A new p–d–π interaction model is proposed to explain the intensity of d–π interaction between metal and π-acid ligand.
• The molecular orbitals of thiourea and its derivatives are clarified to the coordination model of thiourea with metals.
Thiourea and its derivatives often act as strong electron-donating ligands in palladium-catalyzed reactions. Density functional theory calculations were performed to investigate the electronic effects of thiourea ligands in palladium complexes, and a p–d–π interaction model is proposed. In this model, a Pd(d)S(p) interaction is responsible for the increased binding of π acceptor ligands such as CO and olefins, which are present in important intermediates in Pd-catalyzed reactions. This d–p interaction is a four-electron, two-orbital interaction; it raises the energy of the Pd(dyz) orbital, bringing it closer to the π* orbital of the CO or olefin ligand, and increases back donation. Thiourea-ligated transition metals are therefore favorable for the binding of acidic π ligands.
Thiourea and its derivatives often act as strong electron-donating ligands in palladium-catalyzed reactions. Density functional theory calculations were performed to investigate the electronic effects of thiourea ligands in palladium complexes, and a new p–d–π interaction model is proposed.Figure optionsDownload as PowerPoint slide
Journal: Journal of Molecular Structure - Volume 1074, 25 September 2014, Pages 527–533