Bridging μ-η5:η4-Coordination of an Indenyl Ligand and Reductive Coupling of Diazabutadienes in the Assembly of Di- and Tetranuclear Mixed-Valent Ytterbium Indenyldiazabutadiene Complexes

• Published in: Chemistry : a European journal 2006-03, Vol.12 (10), p.2752-2757
• Main Authors: Trifonov, Alexander A., Fedorova, Elena A., Fukin, Georgy K., Baranov, Evgenii V., Druzhkov, Nikolai O., Bochkarev, Mikhail N.
• Format: Article
• Language: English
• Subjects: C-H activation; C-H coupling; lanthanides; mixed- valent compounds; N ligands
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200501181

The redox reaction of [Yb(C9H7)2(thf)2] with the diazabutadiene PhNC(Me)C(Me)NPh (DAD) has been found to depend on the molar ratio of the reactants. Reaction in a 1:2 molar ratio affords the dinuclear mixed‐valent complex [Yb2(μ‐η5:η4‐C9H7)(η5‐C9H7)2{μ‐η4:η4‐PhNC(Me)C(Me)NPh}] containing an indenyl ligand with an unusual μ‐η5:η4 bridging coordination. Reaction of equimolar amounts of these compounds results in an organolanthanide‐mediated reductive coupling of the DAD ligands and formation of the tetranuclear mixed‐valent complex [Yb2(μ‐η5:η4‐C9H7)(η5‐C9H7)2{μ‐η4:η4‐PhNC(CH2)C(Me)NPh}]2 with a novel tetradentate tetraimine ligand. Unusual μ‐η5:η4‐coordination of an indenyl ligand and reductive coupling of diazabutadiene ligands result in the assembly of di‐ and tetranuclear mixed‐valent ytterbium complexes (see picture).