Collect. Czech. Chem. Commun. 2002, 67, 1165-1172

Influence of DNA on the Reaction Rate of an Electron Transfer Process: A Kinetic Study of the Reaction Between [Co(Pyrazinecarboxylate)(NH3)4]2+ and [Fe(CN)6]4- in Aqueous Solutions in the Presence of DNA

Manuel López-López*, Plácido Cárdeno, Francisco J. del Castillo, Luis González, Ana R. Méndez and Ana I. Platero

Colegio de San Francisco de Paula, c/ Sor Ángela de la Cruz 11, 41003 Sevilla, Spain


The kinetics of the electron transfer reaction between tetraammine(pyrazinecarboxylate)cobalt(III), [Co(pyrazinecarboxylate)(NH3)4]2+, and hexacyanoferrate(II), [Fe(CN)6]4- was studied in aqueous solutions in the presence of DNA at concentrations 0-2.28 · 10-3 mol dm-3. A decrease in the rate constant with increasing DNA concentration was observed. The results are interpreted on the basis of the pseudophase model. The meaning of its parameters for the second-order reaction is discussed.

Keywords: DNA; Electron transfer; Kinetics; Pseudophase model; Restricted geometry conditions; Ferrocyanides; Cobalt complexes; Pyrazinecarboxylates.

References: 38 live references.