Photolytic Zirconium Benzyl Bond Cleavage and Subsequent Aryl C−F Activation in Zirconium Complexes of Fluorinated Aryl Diamides

Abstract

Photolysis of Zr(C 6 F 5 NCH 2 CH 2 OCH 2 ) 2 (CH 2 Ph) 2 at 435 nm results in formation of the metalated dimer {Zr[C 6 F 4 NCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 NC 6 F 5 ][CH 2 Ph]} 2 ·(C 7 H 8 ) 2 ( 1 ), the bridging difluoride dimer {Zr[C 6 F 5 NCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 NC 6 F 5 ][F]} 2 [ μ -F] 2 ( 2 ), and bibenzyl. Complex 1 was characterized by NMR spectroscopy ( 1 H, 19 F, 13 C) and X-ray crystallography. In the solid state 1 adopts a pentagonal bipyramidal geometry at each zirconium center with a η 1 -benzyl group occupying one of the axial positions. The bridging difluoride 2 was characterized by 1 H and 19 F NMR spectroscopy. For comparison purposes, Zr(C 6 F 5 NCH 2 CH 2 OCH 2 ) 2 Me 2 ( 3 ) was synthesized and characterized by NMR spectroscopy and X-ray crystallography. Photolysis of 3 at 435 nm does not result in any reaction.