Thermodynamic study of complexation of Zn(II)/L (L− = acetate, indomethacin and diclofenac anions) by isothermal titration calorimetry

Post-synthetic modification and chemical modulation of the ZIF-8 MOF using 3-mercaptopropionic acid (MPA): a multi-technique study on thermodynamic and kinetic aspects

“…61 The ITC-derived enthalpy value corresponding to MPA coordination was determined to be ≃7 kJ mol −1 , assuming that MPA is the limiting reagent and that there are sufficient sites available for coordination on the nanoparticle surface (see details of calculations in the ESI †). This result can be rationalized by considering the reported values for the enthalpy of Zn 2+ complexation with acetate ions in the ethanol phase (≃20 kJ mol −1 ); 62 as the ITC-determined enthalpy would account for the difference between these processes, ITC results strongly suggest that MPA coordination occurs through replacement of MeIm-Zn via coordinative etching (≃8 kJ mol −1 ) rather than direct coordination with Zn 2+ CUS. 62,63 Particle size and crystalline structure temporal evolution of ZIF-8 when using coordination modulation with MPA Having determined the suitable MPA concentration ranges for ZIF-8 stability via the PSM experiments described above, we employed such conditions to assess the influence of MPA as a coordination modulator (CM).…”

“…This result can be rationalized by considering the reported values for the enthalpy of Zn 2+ complexation with acetate ions in the ethanol phase (≃20 kJ mol −1 ); 62 as the ITC-determined enthalpy would account for the difference between these processes, ITC results strongly suggest that MPA coordination occurs through replacement of MeIm-Zn via coordinative etching (≃8 kJ mol −1 ) rather than direct coordination with Zn 2+ CUS. 62,63 Particle size and crystalline structure temporal evolution of ZIF-8 when using coordination modulation with MPA Having determined the suitable MPA concentration ranges for ZIF-8 stability via the PSM experiments described above, we employed such conditions to assess the influence of MPA as a coordination modulator (CM). SAXS experiments were carried out during colloidal synthesis of ZIF-8 following the same procedures as those discussed above.…”

Chemical Equilibrium of Zinc Acetate Complexes in Ethanol Solution. A Theoretical Description through Thermodynamic Cycles

“…It must be mentioned that these experimental records were determined at a temperature condition of 20 °C, however, our theoretical protocol provides thermochemical properties at the temperature condition of 25 °C. For the sake of consistency and advantaging that the enthalpic contribution to the Gibbs free energy of the reactions under consideration are also available, we estimated the experimental Gibbs free energy values at 25 °C for the two reactions under study, using the van’t Hoff equation. Values were corrected from −6.94 and −14.81 kcal·mol –1 at 20 °C to −7.14 and −14.95 kcal·mol –1 at 25 °C for n = 1 and n = 2, respectively.…”

“…The effect of several different source of errors were systematically evaluated and properly balanced; including those affected by the choice of the density functional approximation (DFA, five considered in this study) used to determine the gas phase contributions to the Gibbs free energy of reaction in solution phase. Performance of these procedures were always assessed by confronting the computed results with their experimental counterparts, previously determined …”

“…Performance of these procedures were always assessed by confronting the computed results with their experimental counterparts, previously determined. 27 ■ THEORETICAL PROTOCOLS AND PROCEDURES Computational Details. All our calculations were performed using the Gaussian 09 quantum chemistry computational package.…”