ジメチルスルホキシド中におけるビス（β‐ジケトナト）コバルト（ＩＩ）錯体の溶液内平衡と電気化学的挙動

Abstract

Homogeneous chemical equilibria and electrochemical behaviors of three bis(β-diketonato)cobalt(II) complexes, viz., [Co(hfac)2], [Co(tfac)2] and [Co(acac)2], in di methyl sulfoxide (DNISO) were studied by means of the conductivity flicl electronic spectral measur ements, poktrography, and cyclic voltaminctry with a platinum electrode; where hfac tfac- and acacrepresent the enolate anions of hexafluoroacetylacetone, trifluoroacetylacetone and acetylacetone, respectively. Tetrabutylammonium Perchlorate (TBAP) of 0.05 mol⋅dm-3 in the concentration was used as the supporting electrolyte fur voltammetric measurements. It was found that these complexes were involved in the following chemical equilibria in the solution:In DC polarography, the first wave of [Co(hfac)2] was presumed to be due to the two-electron reduction of CO2+, [Co(hfac)]+ and [Co(hfac)2], and the wave of [Co(acac)2] to that of monomeric and polymeric bis-comlexes. Furthermore, two waves of [Co(tfac)2] corresponded to the two-electron reduction of [Co(tfac)]+ and [Co(tfac)2], respectively; where the first wave included the kinetic current due to the preceding reaction.