Synthesis, characterization, and reactivity of a high-spin iron(II) hydrido complex supported by a PNP pincer ligand and its application as a homogenous catalyst for the hydrogenation of alkenes

• Verfasst von: Ott, Jonas C. [VerfasserIn]
• Verfasst von: Blasius, Clemens K. [VerfasserIn]
• Verfasst von: Wadepohl, Hubert [VerfasserIn]
• Verfasst von: Gade, Lutz H. [VerfasserIn]
• Titel: Synthesis, characterization, and reactivity of a high-spin iron(II) hydrido complex supported by a PNP pincer ligand and its application as a homogenous catalyst for the hydrogenation of alkenes
• Verf.angabe: Jonas C. Ott, Clemens K. Blasius, Hubert Wadepohl, Lutz. H. Gade
• E-Jahr: 2018
• Jahr: February 23, 2018
• Umfang: 9 S.
• Illustrationen: Diagramme
• Fussnoten: Gesehen am 12.03.2020
• Titel Quelle: Enthalten in: Inorganic chemistry
• Ort Quelle: Washington, DC : American Chemical Society, 1962
• Jahr Quelle: 2018
• Band/Heft Quelle: 57(2018), 6, Seite 3183-3191
• ISSN Quelle: 1520-510X
• DOI: doi:10.1021/acs.inorgchem.7b03227
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1692375474

Abstract

This study focused on the synthesis and characterization of a range of low-valent, high-spin iron(II) complexes supported by a carbazole-based PNP pincer-type ligand. The addition of the lithiated ligand (PNP)Li to FeCl2(THF)1.5 yielded the chlorido complex (PNP)FeCl (1), which could be readily converted to the four-coordinate iron(II) alkyl complexes (PNP)FeR [R = CH2SiMe3 (3a), Me (3b), CH2Ph (3c)]. These iron(II) complexes were fully characterized by X-ray analysis and a comprehensive, density-functional-theory-assisted study with complete assignment of their paramagnetic 1H and 13C NMR spectra. Treatment of 1 with KHBEt3 or the addition of molecular hydrogen to (PNP)FeR afforded a high-spin iron(II) PNP hydrido complex, which was identified as the dimer [(PNP)Fe(μ-H)]2 (4) with two bridging hydrido ligands between the iron centers. Exposing complexes 1 and 4 to carbon monoxide led to the corresponding six-coordinate, diamagnetic complexes (PNP)Fe(CO)2Cl (2) and (PNP)Fe(CO)2H (5), of which 2 was present as cis/trans isomers. Furthermore, 4 was found to be an active catalyst for the hydrogenation of alkenes.