Reaction of NO2 with palladium(II) and platinum(II) aryl complexes; the crystal structure of tans-[Pd(ONO2)2(OPPh3)(PPh3)]
Abstract
[Pd(C6H4NO2-p)I(PPh3)2] and [Pd(Ph)Cl(Ph2PCH2PPh2)] do not react with NO but react with NO2 to give [Pd(NO3)2(OPPh3)(PPh3)] and [PdCl(NO3)(Ph2PCH2CH2PPh2)] respectively. The structure of [Pd(NO3)2(OPPh3)(PPh3)] has been confirmed by X-ray crystallography, the metal co-ordination polyhedron being planar with trans monodentate nitrato groups. Reaction of [Pt(R)I(PPh3)2](R = C6H4NO2-p or Ph) with NO2 gave [Pt(R)(NO3)(PPh3)2], species shown spectroscopically to contain monodentate nitrate. Treatment of [Pd(NO2)2(PPh3)2] with NO2 gave [Pd(NO3)2(PPh3)2], while NO or CO caused deoxygenation of [Pd(NO3)2L2](L = PPh3 or PEt3) and [Pt(Ph)(NO3)(PPh3)2] to the nitro species [Pd(NO2)2L2] and [Pt(Ph)(NO2)(PPh3)2]. Reaction of [Ni(NO3)2(PEt3)2] with NO or NO2 afforded [Ni(NO3)2(OPEt3)2]. The possible mechanisms of these oxygen-transfer reactions are briefly discussed.