DIFERROCENYLTRIPHOSPHINES 1 - 5-COORDINATE RUTHENIUM COMPLEXES

The ligand 1-(1'-diphenylphosphinoferrocenyl)phenylphosphine, triphosf er, reacts with dichlorotris-triphenylphosphineruthenium(II) to give t he complex [(triphosfer)RuCl2] (17), in almost quantitative yield. Thi s complex reacts with CO at ambient temperature to afford [(triphosfer )Ru(CO)Cl-2]. Three related complexes, H4)Fe-mu(2)-(eta-C5H4P(R')eta-C 5H4)Fe(eta-C5H4R2)} RuCl2], R,R'=Ph, iPr (18-20), exhibit identical ch emical properties. Reaction of complexes 17-20 with excess PMe2Ph resu lts in the deligation of the ferrocene ligand. The electrochemistry sh ows that while the diferrocenyltriphosphine ligands undergo a single t wo-electron oxidation, irreversible in character, complexes (17-19) ex hibit two separated one-electron oxidations having features of chemica l reversibility. This data suggests that while within the ligands no e lectronic communication exists between the two ferrocene subunits, com plexation with RuCl2 allows communication between the two ferrocenes. The single crystal X-ray structure of [(triphosfer)RuCl2] has been det ermined. (C) 1998 Elsevier Science S.A. All rights reserved.