Hideo Doine

Electrochemical studies of binuclear copper(II) complexes

Abstract Two symmetrical binuclear complexes of copper(II) with Schiff base ligands have been studied by cyclic voltammetry. There is no evidence of difference between the CuIICuII/CuIICuI and CuIICuI/CuICuI reduction potentials, nor of any CuI → CuII intervalence charge transfer. The mixed-valence CuIICuI complexes are considered to be of the Robin and Day Class I.

MONO- AND BINUCLEAR RUTHENIUM(II) SCHIFF-BASE COMPLEXES: SPECTROPHOTOMETRIC AND ELECTROCHEMICAL STUDIES

Abstract As part of a study of electron transfer processes in mixed-valence binuclear complexes, we report here results of electrochemical and spectrophotometric studies of the complex I, and of its mononuclear analogue II (P = P(C6H5)3). In the semi-oxidised RuIII RuII complex corresponding to I, we find evidence of a small extent of interaction between the Ru atoms, as reflected in the comproportionation constant Kcom (eqn. 1). but the corresponding intervalence charge transfer spectrum is not detected.

A cobalt(III)-copper(II) binuclear complex

Abstract The mixed-metal macrocyclic complex [CoIIICuIILCl3], where L is the 2:2 condensation product of 2,6-diformyl-4-methyl phenol and 1,3-diaminopropane, has been prepared and characterized spectroscopically and electrochemically. Cyclic voltammetry (in DMF) indicates reversible reduction at the copper(II) centre and a relatively slow intramolecular copper(I) to cobalt(III) electron transfer.

Equilibria and kinetics of dissociation of triphenylphosphine from [N,N′-ethylenebis(salicylideneiminato)]bis(triphenylphosphine)ruthenium(II) in benzene

The reactions (i) and (ii)[H2salen =N,N′-ethylenebis(salicylideneimine)] in benzene solution have been studied by both equilibrium and kinetic spectrophotometric methods. At 25 °C, k1= 1.61 ± 0.02 [Ru(salen)]+ PPh3 [graphic omitted] [Ru(salen)(PPh3)](i), [Ru(salen)(PPh3)]+ PPh3 [graphic omitted] [Ru(salen)(PPh3)2](ii) dm3mol–1s–1, k–1=(2.7 ± 0.4)× 10–4s–1, k2=(1.18 ± 0.05)× 10–1dm3mol–1s–1, k–2=(1.20 ± 0.09)× 10–3s–1, K1=(0.60 ± 0.08)× 104 dm3 mol–1, and K2= 98 ± 6 dm3 mol–1.