Platinum complexes of (R)-N,N-bis(2-(diphenylphosphino)ethyl)-1-phenyl-ethylamine: their synthesis and characterisation

Both neutral and ionic platinum complexes of (R)-N,N-bis-(2-diphenylpho sph inoethyl)-1-phenyl-ethylamine (PNP) were synthesised. In the reaction of Pt Cl2(PhCN)(2) and PNP cis-PtCl2(eta (2)-P,P-PNP) (1) was formed coordinating PNP as a P,P-bidentate ligand. Diastereotopic phosphorus atoms were observ ed in P-31 NMR upon addition of SnCl2 to the parent complex (1) due to the formation of [PtCl(PNP)][SnCl3] (2a). The formation of similar complex cati ons, [PtX(PNP)](+) (where X = I (4), CN (5)) containing PNP as a terdentate ligand was also observed when KI and KCN was added in the presence of SnCl 2, which formed trichlorostannate counterion. The addition of PPh3 to 1 res ulted in the partial formation of [Pt(PPh3)(PNP)](2+) (3), which could be a ccomplished upon addition of SnCl2. The catalytic activity of the platinum- PNP system in the hydroformylation of styrene is low. (C) 2001 Elsevier Sci ence B.V. All rights reserved.