Complex formation with heptane-3,5-dione. Stabilities of some bivalent metal chelate complexes in aqueous dioxan (50%)

Abstract

The acid dissociation constant of heptane-3.5-dione, together with the stability constants of its chelate complex with cobalt(i1). have been determined in aqueous dioxan (50% v/v) over the temperature range 5-45 "C. From these results, values of the enthalpy and entropy of protonation and chelation have been calculated. Stability constants of heptane-3.5-dione chelate complexes of copper( 11). nickel(l1). manganese(l1). and magnesium( 11) have been measured at 25 ' C .' Stability Constants of Metal-ion Complexes,' Cham. SOC.