Fluorophosphine complexes of ruthenium and osmium. Part 3. Monomeric ruthenium(II) and osmium(II) halogeno-complexes

Abstract

The complex [RuCl₂(PPh₃)₃] or [RuCl(H)(dma)(PPh₃)₂](dma = MeCONMe₂) reacts with 2 mol of PF₃ to give cis-[RuCl₂(PF₃)₂(PPh₃)₂]. The analogous complex cis-[RuCl₂{PF₂(NMe₂)}₂(PPh₃)₂] made from either [RuCl₂-(PPh₃)₃] or [{RuCl₂(OCMe₂)(PPh₃)₂}₂]. undergoes ready dissociation of PPh₃ in solution to give [RuCl₂{PF₂-(NMe₂)}₂(PPh₃)]. Trifluorophosphine or PF₂(NMe₂) reacts with solutions of [RuCl₂(PPh₃)₃] in dimethylformamide to give complexes of the type [RuCl₃(dmf)L(PPh₃)₂][L = PF₃ or PF₂(NMe₂)] which readily undergo dimerisation reactions to yield binuclear complexes [(Ph₃P)₂LRuCl₃RuCl(L)(PPh₃)]. Reduction of [OsCl₃-(PMe₂Ph)₃] with zinc in the presence of PF₃ affords trans-[OsCl₂(PF₃)(PMe₂Ph)₃] which can be isomerised to the cis complex. The related trans- and cis-[OsCl₂(PF₃)₂(PMe₂Ph)₂] are also described; the former complex exhibits a very large ²J(PMP′) coupling constant between the two PF₃, ligands. Structures of all the complexes reported have been elucidated by ¹⁹F and ³¹P n.m.r. spectroscopy.