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 [Ru(2)(II,III)(R(1)COO)(2)(R(2)COO)(2)Cl] (R(1) = Me, R(2) = 2,4,6-(i)Pr-Ph or R(1) = R(2) = (t)Bu) with two equivalents of the octahedral manganese complex [Mn(I)(CO)(CN)((t)BuNC)(4)] leads to the formation of cyanide bridged heteronuclear coordination compounds of the general formula {[Ru(2)(II,III)(R(1)COO)(2)(R(2)COO)(2)][Mn(I)(CO)(CN)((t)BuNC)(4)](2)}Cl. In solution an intramolecular electron transfer from manganese towards the multiply bonded Ru(2) core occurs that is verified by EPR and IR spectroscopy, magnetic measurements and DFT calculations. Nevertheless, disproportionation of an initially formed {Mn(I)-Ru(2)(II,III)-Mn(I)}(+) adduct into {Mn(II)-Ru(2)(II,III)-Mn(I)}(2+) and {Mn(I)-Ru(2)(II,II)-Mn(I)} species cannot be completely ruled out.

Manganese, technetium and rhenium

“…49 Cyanide-bridged heteronuclear manganese/ruthenium coordination compounds have been prepared and intramolecular electron transfer investigated. 50 The molecular wheel complex [Mn 3 Cr 4 (NCS) 6 (Htea) 6 ] has been synthesised by reaction of zero-valent manganese, Reineckes salt, ammonium thiocyanate and triethanolamine (H 3 tea). 51 Meanwhile, triethanolamine has been used in the synthesis of a new supertetrahedral icosanuclear and two new ring-like decanuclear mixed-valent manganese(II/III) clutsers.…”