72036-58-9Relevant articles and documents
Effect of fluorine substitution, pressure and temperature on the tautomeric equilibria of acetylacetonate β-diketones
Wallen,Yonker,Phelps,Wai
, p. 2391 - 2394 (1997)
The equilibrium between the keto and enol tautomers of acetylacetone, trifluoroacetylacetone and hexafluoroacetylacetone in the neat liquid state and dissolved in supercritical fluid carbon dioxide have been studied, as a function of pressure and temperature, by 1H NMR. This allows determination of the thermodynamic parameters, ΔH and ΔS, for the keto-enol equilibrium. The observed trends are well correlated with extraction results for this class of compounds.
Kinetics and Mechanism of Ligand Exchange in Tetrakis(acetylacetonato)zirconium(IV) in Organic Solvents
Jung, Woo-Sik,Ishizaki, Haruro,Tomiyasu, Hiroshi
, p. 1077 - 1082 (2007/10/02)
The kinetics of ligand exchange between (acac = acetylacetonate) and free acetylacetone (Hacac) in various organic solvents such as CDCl3, C6D6 and CD3CN has been studied by the 1H NMR line-broadening method.The observed first-order rate constant kobs for acac exchange in CDCl3 and C6D6 is expressed as a function of concentration of Hacac in the enol form: kobs = (k2 + k3,HA)K1enol/(1 + K1enol), where K1 is the equilibrium constant for the formation of the nine-co-ordinate adduct .The rate constants k2 and k3,HA correspond to those of proton transfer from co-ordinated Hacac to leaving acac and ring opening of acac in the adduct, respectively.Activation parameters ΔH(excit.)/kJ mol-1 and ΔS(excit.)/J K-1 mol-1 for the K2 + k3,HA path are 33.7 +/- 2.3, -87.8 +/- 8.1 in CDCl3 and 38.1 +/- 0.1, -85.9 +/- 0.4 in C6D6.The rate constants kobs in CD3CN are much smaller than those in CDCl3 and C6D6, and increase linearly with increasing enol.Addition of water and dimethyl sulfoxide to C6D6 solutions results in acceleration and retardation of the exchange rate, respectively.The deuterium kinetic isotope effect was observed by using acetylacetone in place of Hacac in C6D6.The results are discussed in connection with those of acac exchange in other complexes (M = Hf(4+), Ce(4+), Th(4+) or U(4+)).