Bi- and tri-nuclear cyano-bridged ruthenium complexes containing (L-L)₂Ru^IIand Cp(EPh₃)₂Ru^II moieties [(L-L)= 2,2'-bipyridine, 1,10-phenanthroline; Cp = η⁵-(C₅H₅)^-; E = P, As, Sb]

Abstract

The cyano and isonitrilo bridged di- and tri-nuclear ruthenium(II) complexes of the types, [NC(L-L)₂RuCNRu(EPh₃)Cp]⁺Y^-, [CI(L-L)₂RuNCRu(EPh₃)₂Cp]Y and [(L-L)₂Ru{NCRu (EPh₃)₂ Cp}Y₂ [where (L-L)=2,2'-bipyridine, 1,10-phenanthroline; E=P, As, Sb; CP=η⁵-(C₅H₅)^-; Y = (PF₆)^-, (BPh₄)^-] have been prepared. They have been characterised by elemental analyses. spectral (IR, ¹H NMR and electronic) and redox data. The redox and the spectral properties of the [(L-L)₂Ru^ll] moiety have been rationalised in terms of the competitive π-back bonding by the second Ru^ll ion centered at [RuCp(EPh₃)₂]⁺. The (L-L)₂CIRu^ll group in isonitrile bridged complexes is more easily oxidised than that in the corresponding acetonitrile analogue which accords with the spectral behaviour of the complexes.