Five-coordinate complexes of palladium(ii) and platinum(ii) with α-diimine and 1,5-cyclooctadiene ligands

The five-coordinate complexes [PtMe(cod)(N–N′)]BF4 [cod = η2,η2-cyclooctadiene, N–N′ = (6-R2)C5H3N-2-CHNR1 (R1 = C6H4OMe-4, R2 = H (1), Me (2); R1 = CMe3, R2 = H (3), Me (4); R1 = (R)-bornyl, R2 = Me (5))] are readily obtained from the reaction of [PtClMe(cod)] with N–N′ in the presence of NaBF4. The preparation of [PtMe(cod)(6)]BF4 (6 = 4-MeOC6H4NCHCHNC6H4OMe-4), [PdMe(cod)(N–N′)]BF4 and [PtCl(cod)(N–N′)]BF4 (N–N′ = 2, 4) requires chloride abstraction by AgBF4 from [PtClMe(cod)], [PdClMe(cod)] and [PtCl2(cod)], respectively, followed by coordination of N–N′. The NMR spectral data suggest a trigonal-bipyramidal structure with chelating cod and N–N′ ligands, where the α-diimine and one CC bo…