Some anionic ruthenium(III) and rhodium(III) complexes of tertiary monophosphines and arsines

Abstract

Various methods of preparing ruthenium(III) anions of formula M[RuCl₄(PR₃)₂](M = Me₄N⁺, Ph₄As⁺; Pr₃= PPh₃, PMe₂Ph, PEt₃, P(OPh)₃), and M[RuX₄(AsPh₃)₂](M = Me₄N⁺, Et₄N⁺, Ph₄As⁺; X = Cl, Br) are described including one involving ‘oxidation’ of RuCl₂(PPh₃)_{3 or 4} by concentrated hydrochloric acid. Methods of synthesising the isomorphous complexes Ph₄As[RhCl₄(PR₃)₂](PR₃= PPh₃, PMe₂Ph)via RhCl(PPh₃)₃ and trans-[RhClCO(PPh₃)₂] are also described. A comparison of the stability of these anions towards solvolysis and various exchange reactions is made. From n.m.r. and i.r. spectral studies, the probable structures of the complexes are shown to be trans.