Photolytic zirconium benzyl bond cleavage and subsequent aryl C−F activation in zirconium complexes of fluorinated aryl diamides

Photolysis of Zr(C6F5NCH2CH2OCH2)2(CH2Ph)2 at 435 nm results in formation of the metalated dimer {Zr[C6F4NCH2CH2OCH2CH2OCH2CH2NC6F5][CH2Ph]}2·(C7H8)2 (1), the bridging difluoride dimer {Zr[C6F5NCH2CH2OCH2CH2OCH2CH2NC6F5][F]}2[μ-F]2 (2), and bibenzyl. Complex 1 was characterized by NMR spectroscopy (1H, 19F, 13C) and X-ray crystallography. In the solid state 1 adopts a pentagonal bipyramidal geometry at each zirconium center with a η1-benzyl group occupying one of the axial positions. The bridging difluoride 2 was characterized by 1H and 19F NMR spectroscopy. For comparison purposes, Zr(C6F5NCH2CH2OCH2)2Me2 (3) was synthesized and characterized by NMR spectroscopy and X-ray crystallography. Photolysis of 3 at 435 nm does not result in any reaction.