Charge type effects on the temperature dependence of intervalence transfer in ferrocyanide substituted ruthenium(III) amine and aminopolycarboxylate compounds

The K4[RuIII(hedtra)NCFeII(CN)5] (3) (hedtra=N-hydroxyethylethylenediaminetriacetate) complex has been synthesised and characterised by physicochemical analysis. The temperature dependence of intervalence transfer in 3 has been studied and compared with that observed in [RuIII(edta)NCFeII(CN)5]5− (1) and [RuIII(NH3)5NCFeII(CN)5]− (2), complexes. The charge type on the ruthenium centre of the binuclear complexes has been found to effect the intervalence thermochromism. This has been discussed in terms of a charge type effect on the temperature dependency of ΔE (vibrationally relaxed initial state/final state separation energy) and the χ (reorganisation energy) component of EIVCT (intervalence charge transfer energy).