Heterobimetallic cluster cations from the reactions of diphosphazane-bridged derivatives of [Ru2(CO)9] with metal-containing electrophiles: mechanism of the one-electron oxidation of [Ru2(µ-CO)(CO)4{µ-(RO)2PN(Et)P(OR)2}2] by silver salts

Abstract

Reaction of [Ru₂(µ-CO)(CO)₄{µ-(RO)₂PN(Et)P(OR)₂}₂](R = Me or Prⁱ) with [AuCl(PPh₃)], [Cu(MeCN)₄]⁺, and HgCl₂ gives cationic products in which the metal substrate is either co-ordinated terminally as in [Ru₂(HgCl)(CO)₅{µ-(RO)₂PN(Et)P(OR)₂}₂]⁺ or in the bridging mode as in [Ru₂{µ-Au(PPh₃)}(µ-CO)(CO)₄{µ-(RO)₂PN(Et)P(OR)₂}₂]⁺, the structure of the latter being confirmed X-ray crystallographically; silver(I) salts similarly afford products of the type [Ru₂(µ-AgL)(µ-CO)(CO)₄{µ-(RO)₂PN(Et)P(OR)₂}₂]⁺(L = acetone, acetonitrile, etc.) but, weakly co-ordinating ligands L, these species readily rearrange with the nature of the final product being dependent on L and the solvent employed; [Ru₂(µ-AgL)(µ-CO)(CO)₄{µ-(RO)₂PN(Et)P(OR)₂}₂]⁺ is shown to be an intermediate in the one-electron oxidation of [Ru₂(µ-CO)(CO)₄{µ-(RO)₂PN(Et)P(OR)₂}₂].