The Coordination Chemistry of 2-(diphenylamino)pyridine

2-(Diphenylphosphinoamino)pyridine, dppap [Ph(2)PNHpy], and over 40 illustrative examples of its complexes have been prepared. Monodentate, bidentate and bridging co-ordination of the neutral (and bidentate deprotonated ligand) has been demonstrated in a range of palladium, platinum and gold complexes. Ten demonstrative examples have been characterised by single crystal X-ray diffraction. Ph(2)PNHpy exists as hydrogen-bonded dimer pairs; cis-[PtCl(Ph(2)PNHpy-P,N){Ph(2)PNHpy-P}]Cl packs in hydrogen-bonded infinite chains; cis-[Pt(Ph(2)PNpy-P,N)(2)] and cis-[Pd(Ph(2)PNpy-P,N)(2)] are isomorphous. The structures of cis-[Pd(Ph(2)PNHpy-P,N)(2)][BF4](2), [AuCl(Ph(2)PNHpy-P)], [Pt(C8H12OMe)(Ph(2)PNpy-P,N)]. H2O illustrating hydrogen-bonding, cis-[PtCl(Ph(2)PNHpy-P,N)(PMe3)]Cl, cis-[PtCl(Ph(2)PNpy-P,N)(PMe3)] and cis-[PtCl(Ph(2)PNHpy-P,N)(P(OPh)(3))]Cl are also reported.