Oxidative Addition of Carbon鈥揅arbon Bonds with a Redox-Active Bis(imino)pyridine Iron Complex

详细信息    查看全文

• 作者：Jonathan M. Darmon ; S. Chantal E. Stieber ; Kevin T. Sylvester ; Ignacio Fern谩ndez ; Emil Lobkovsky ; Scott P. Semproni ; Eckhard Bill ; Karl Wieghardt ; Serena DeBeer ; Paul J. Chirik
• 刊名：The Journal of the American Chemical Society
• 出版年：2012
• 出版时间：October 17, 2012
• 年：2012
• 卷：134
• 期：41
• 页码：17125-17137
• 全文大小：709K
• 年卷期：v.134,no.41(October 17, 2012)
• ISSN：1520-5126

文摘

Addition of biphenylene to the bis(imino)pyridine iron dinitrogen complexes, (^iPrPDI)Fe(N₂)₂ and [(^MePDI)Fe(N₂)]₂(渭₂-N₂) (^RPDI = 2,6-(2,6-R₂鈥擟₆H₃鈥擭鈺怌Me)₂C₅H₃N; R = Me, ⁱPr), resulted in oxidative addition of a C鈥擟 bond at ambient temperature to yield the corresponding iron biphenyl compounds, (^RPDI)Fe(biphenyl). The molecular structures of the resulting bis(imino)pyridine iron metallacycles were established by X-ray diffraction and revealed idealized square pyramidal geometries. The electronic structures of the compounds were studied by M枚ssbauer spectroscopy, NMR spectroscopy, magnetochemistry, and X-ray absorption and X-ray emission spectroscopies. The experimental data, in combination with broken-symmetry density functional theory calculations, established spin crossover (low to intermediate spin) ferric compounds antiferromagnetically coupled to bis(imino)pyridine radical anions. Thus, the overall oxidation reaction involves cooperative electron loss from both the iron center and the redox-active bis(imino)pyridine ligand.