Both neutral and ionic platinum complexes of (R)-N,N-bis(2-diphenylphosphinoethyl)-1-phenyl-ethylamine (PNP) were synthesised. In the reaction of PtCl 2 (PhCN) 2 and PNP cis-PtCl 2 (η 2 -P,P-PNP) (1) was formed coordinating PNP as a P,P-bidentate ligand. Diastereotopic phosphorus atoms were observed in 3 1 P NMR upon addition of SnCl 2 to the parent complex (1) due to the formation of [PtCl(PNP)][SnCl 3 ] (2a). The formation of similar complex cations, [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 PPh 3 to 1 resulted in the partial formation of [Pt(PPh 3 )(PNP)] 2 + (3), which could be accomplished upon addition of SnCl 2 . The catalytic activity of the platinum-PNP system in the hydroformylation of styrene is low.