Reactions of metal ions with triketones in solution. Part 1. Formation constants for the systems of heptane-2,4,6-trione, 1-phenylhexane-1,3,5-trione, 1,5-diphenylpentane-1,3,5-trione, and 2,2′-dihydroxybenzophenone with proton, nickel(II), and cobalt(II)

Abstract

The equilibrium constants for the proton reactions of heptane-2,4,6-trione, 1-phenylhexane-1,3,5-trione, 1,5-diphenylpentane-1,3,5-trione, and 2,2′-dihydroxybenzophenone have been determined in methanol–water solutions (70:30 v/v) using potentiometric and spectrophotometric methods. The compositions and log β values of the complexes formed in solution by these ligands with nickel(II) and cobalt(II) have also been determined. All four ligands form 1 : 1 and 2 : 2 complexes with these metal ions.