Unexpected C−F activation during redox transmetallation with silverN,N′‐bis(2,6‐difluorophenyl)formamidinate

Abstract The trivalent lanthanoid formamidinates, [Yb 2 (DFForm) 4 F 2 (py) 2 ] ⋅ CH 3 CN ( 1 ) (DFForm= N,N ′‐bis(2,6‐difluorophenyl)formamidinate), and [La 6 (DFForm) 8 F 8 O(CH 3 CN) 2 ] ⋅ 6CH 3 CN ( 2 ) have been prepared from redox transmetallation (RT) reactions employing lanthanoid metals and silver formamidinate (AgDFForm) in CH 3 CN. C−F activation was observed in both reactions. The structure of 1 is a fluorine bridged dimer with two seven‐coordinate ytterbium metal ions. Surprisingly the lanthanum complex is a trivalent cage with an unexpected central oxygen atom. [La 6 (DFForm) 8 F 8 O(CH 3 CN) 2 ] ⋅ 6CH 3 CN ( 2 ) formed a 15 membered ring cage of six La atoms, eight F and one O at the centre. There are three different La 3+ ions in 2 with two different coordination numbers. All the La atoms are coordinated by four bridging fluorides and the central oxygen.