Inorganic Chemistry, Vol.39, No.2, 200-205, 2000
Preparations and electrochemical properties of pyrazine-bridged ruthenium-binuclear complexes exhibiting molecular hysteresis
Three binuclear Ru complexes cis-,cis-[(NH3)(4)(L)Ru-pz-Ru(NH3)(4)(dmso)](PF6)(4) (L = NH3 (4), pyridine (5), benzonitrile (6); dmso = dimethyl sulfoxide) have been prepared, and their electrochemical behavior, exhibiting molecular hysteresis, is reported. Simulations of cyclic voltammograms and thin-layer cyclic voltammograms have provided redox potentials, isomerization rates, and interconversion rates of the complexes. The rates of the conversions between two isomeric intermediate states have been determined to be 5 x 10(-6) and 4 x 10(-4) s(-1) for the complex 4, 4 x 10(-5) and 4 x 10(-4) s(-1) for the complex 5, and 2 x 10(-4) and 5 x 10(-5) s(-1) for the complex 6. The equilibrium parameters between these states are discussed in relation to the redox potentials of the complexes.