Intramolecular electron transfer in cyanide bridged adducts comprising Ru~(II)/Ru~(III) tetracarboxylate and [Mn~I(CO)(CN) (~tBuNC)_4] units

摘要

Reaction of mixed valence ruthenium tetracarboxylates [Ru_2~(II,III)(R~1COO)_2(R~2COO)_2Cl] (R~1 = Me, R~2 = 2,4,6-~iPr-Ph or R~1 = R~2 = ~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 {[Ru_2~(II,III)(R~1COO) _2(R~2COO)_2][Mn~I(CO)(CN)(~tBuNC)_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.