Synthesis of Functional Chelating Diphosphines Containing the Bis[2-(diphenylphosphino)ethyl]amino Moiety and the Use of These Materials in the Preparation of Water-Soluble Diphosphine Complexes of Transition Metals

Acylation of bis[2-(diphenylphosphino)ethyl]amine provides a flexible synthesis of functionalized chelating diphosphines. This reaction offers a route to diphosphine complexes of transition metals having a wide range of structures and physical properties and especially to water-soluble complexes. The aqueous solubility of the free ligands and of the complexes prepared from them depend on the ligand, on the metal, and on other materials (especially surfactants) present in the solution. We describe typical preparations of ligands and outline the properties of their complexes with certain transition metals.