Chelate compound stability constant calculations on metal diketonate complexes

Acetylacetone (CH₃COCH₂COCH₃ or Hacac) may give up a proton and chelate with a metal ion through the two oxygen atoms. The stability constant for the neutral complex (given as log β_Σ) in aqueous solution can be calculated using the electrostatic relation log βΣ = N_AV_c²e²/(2.3RT?/d) when cations in S states are involved. Larger values that reflect exchange related electron correlation as well as electrostatic contributions to cohesive energy are obtained using transition metal ions. Separate values for the two energies are determined (see the text for definitions of the symbols).