Intramolecular electron transfer in cyanide bridged adducts comprising RuII/RuIII tetracarboxylate and [MnI(CO)(CN)(tBuNC)4] units

Abstract

Reaction of mixed valence ruthenium tetracarboxylates [Ru₂^II,III(R¹COO)₂(R²COO)₂Cl] (R¹ = Me, R² = 2,4,6-ⁱPr-Ph or R¹ = R² = ^tBu) with two equivalents of the octahedral manganese complex [Mn^I(CO)(CN)(^tBuNC)₄] leads to the formation of cyanide bridged heteronuclear coordination compounds of the general formula {[Ru₂^II,III(R¹COO)₂(R²COO)₂][Mn^I(CO)(CN)(^tBuNC)₄]₂}Cl. In solution an intramolecular electron transfer from manganese towards the multiply bonded Ru₂ core occurs that is verified by EPR and IR spectroscopy, magnetic measurements and DFT calculations. Nevertheless, disproportionation of an initially formed {Mn^I–Ru₂^II,III–Mn^I}⁺ adduct into {Mn^II–Ru₂^II,III–Mn^I}²⁺ and {Mn^I–Ru₂^II,II–Mn^I} species cannot be completely ruled out.