Formation and properties of dimethylamine complexes of palladium(II) having trans phosphorus spanning terdentate ligands.

Abstract

Dimethylamine complexes of palladium(II) [(PCP)Pd(NHMe2)](OTf) (PCP = 2,6-(R2PCH2)(2)C6H3); R = Ph (1), R = Cy (2)), have been prepared from the reaction of (PCP)Pd(OTf) and dimethylamine. The complex 1 is stable both in solution and in the solid state, while 2 is stable only in-solution in the presence of dimethylamine although the formation of 2 in solution is quantitative by NMR spectroscopy. A solution NMR spectroscopic study shows that dimethylamine favors over carbon monoxide in the coordination sphere of palladium(II) having rigid terdentate ligands. The complexes 1 and 2 in chlorinated solvents undergo a chlorine abstract reaction yielding Pd(2,6-(R2PCH2)(2)C6H3)Cl in the presence of a base such as dimethylamine and DAB-CO (diazabicyclooctane), in which a transient dimethylamido palladium(II) species likely involves.