New mono- and bis(pentafluorophenyl)palladium(II) complexes with iminophosphine ligands. Crystal structure of [Pd(C 6F 5)(SC 6H 5)( o-Ph 2PC 6H 4–CHN iPr)

Abstract

The synthesis of new mono- and bis(pentafluorophenyl) derivatives of palladium(II) with the mixed-donor bidentate ligands o-Ph 2 PC 6H 4–CH NR (RN–P) has been achieved. The new complexes of general formula [Pd(C 6F 5) 2(RN–P)] [R=Me ( 1), Et ( 2), n Pr ( 3) i Pr ( 4), t Bu ( 5), Ph ( 6), NH–Me ( 7)] and [Pd (C 6F 5)Cl(RN–P)] [R=Me ( 8), i Pr ( 9), NH–Me ( 10)] have been, respectively, prepared by reaction between the labile precursors cis-[Pd(C 6F 5) 2(PhCN) 2] or [{Pd(C 6F 5)(tht)(μ-Cl)} 2] (tht=tetrahydrothiophene) and the corresponding iminophosphines. Complex ( 9) undergoes metathetical exchange of chloride with anionic monodentate ligands when reacting with alkaline salts, giving the complexes of formula [Pd(C 6F 5)X( i PrN–P)] [X=Br ( 11), I ( 12), CN ( 13), SCN ( 14), SC 6H 5 ( 15), p-SC 6H 4Me ( 16), p-SC 6H 4NO 2 ( 17), OMe ( 18)]. Furthermore, when the chloropentafluorophenyl complex ( 9) was treated with silver trifluoromethanesulfonate in the presence of tertiary phosphines, the cationic derivatives [Pd(C 6F 5)(L)( i PrN–P)](CF 3SO 3) [L=PEt 3 ( 19), PMe 2Ph ( 20), PMePh 2 ( 21)] were obtained in good yield. The new complexes were characterized by partial elemental analyses and spectroscopic methods (IR, 1H, 19F and 31P NMR). The molecular structure of complex ( 15) has been determined by a single-crystal diffraction study, showing that the iminophosphine act as chelating ligand with coordination around the palladium atom slight distorted from the square-planar geometry.