New cationic palladium (II) and rhodium (I) complexes of [Ph2PCH2C(Ph)double bond; length as m-dashN(2,6-Me2C6H3)]

Treatment of the bulky iminophosphine ligand [Ph2PCH2C(Ph)double bond; length as m-dashN(2,6-Me2C6H3)] (L) with [M(CH3CN)2(ligand)]+n, where for M = Pd(II): ligand = η3-allyl, n = 1, and for M = Rh(I), ligand: 2(C2H4), 2(CO) or cod, n = 0, yields the mono-cationic iminophosphine complexes [Pd(η3-C3H5)(L)][BF4] (1), [Rh(cod)(L)][BF4] (2), [Rh(CO)(CH3CN)(L)][BF4] (3), and cis-[Rh(L)2][BF4] (4). All the new complexes have been characterised by NMR spectroscopy and X-ray diffraction. Complex 1 shows moderate activity in the copolymerisation of CO and ethene but is inactive towards Heck coupling of 4-bromoacetophenone and n-butyl acrylate.