New mixed-donor unsymmetrical P-N-P ligands and their palladium(II) complexes

Article abstract of DOI:10.1039/b103501k

Unsymmetrical bidentate ligands R₂P(E)-N(H)-P(E′)R′₂ [R, R′ = Ph, OPh, ⁱPr; E, E′ = O, S, Se] have been synthesised using the condensation reaction of an amino compound, R₂P(E)NH₂ [R = PhO, Ph; E = O, S, Se], with a phosphorus electrophile, R′₂P(E′)C1 [R′ = ⁱPr, Ph, OPh; E′ = O, S, Se]. Deprotonated ligands (with KO^tBu) can be treated with Pd(OAc)₂ to give [Ph₂P(S)-N-P(O)(OPh)₂]₂Pd, [ⁱPr₂P(S)-N-P(O)(OPh)₂]₂Pd and [Ph₂P(S)-N-P(S)(OPh)₂]₂Pd, which show either four-membered or six-membered chelate rings. The new compounds were studied spectroscopically (NMR, IR and Raman) and by X-ray crystallography.