Enthalpy–Entropy Compensation Effect in Chemical Kinetics and Experimental Errors: A Numerical Simulation Approach

Perez‐Benito, Joaquin F.; Mulero-Raichs, Mar

doi:10.1021/acs.jpca.6b08079

Cited by 29 publications

(20 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[43][44][45][46][47] Nevertheless, there seem to be reliable evidences supporting the physicochemical meaning of some of those correlations. 48,49 In the present case, despite the slope of the plot (isokinetic temperature, T iso = 296 ± 21 K) being almost coincident with the mean experimental temperature (T exp = 298 K), the correlation was statistically significant since, according to the p-test, 50 the probability of it being caused by random experimental errors was relatively low (P = 0.0106).…”

Section: Reactions Of Cr(iii) With Other Amino Acids: Kineticcontrasting

confidence: 46%

Ligand Sequential Replacement on Chromium(III)–Aqua Complexes by l-Alanine and Other Biological Amino Acids: A Kinetic Perspective

Perez‐Benito

Martinez-Cereza

2018

J. Phys. Chem. A

Self Cite

View full text Add to dashboard Cite

The ligand sequential replacement on chromium(III)-aqua complexes by l-alanine in slightly acidic aqueous solutions (pH range: 3.55-5.61) has been kinetically followed by means of UV-vis spectrophotometry. A two rate constant model has been applied to fit the absorbance-time data, corresponding to the formation ( k) and decay ( k) of an intermediate not reactive enough to be in steady state (long-lived intermediate). The kinetic orders of the amino acid were fractional (0.40 ± 0.03 for k and 0.40 ± 0.02 for k). The two steps showed base catalysis, and the activation energies were 60 ± 3 (for k) and 83 ± 6 (for k) kJ mol. The rate constants for the coordination of the first l-alanine ligand followed the sequence CrOH < Cr(OH) < Cr(OH), Cr being almost inactive. This suggests that the increase in the reaction rate with increasing pH was caused by the enhancement of the lability of the Cr(III)-aqua bonds induced by the presence of hydroxo ligands. The activation parameters for a series of ligand substitution on Cr(III)-aqua complexes by organic molecules yielded a statistically significant enthalpy-entropy linear plot with an isokinetic temperature of 296 ± 21 K.

show abstract

Section: Reactions Of Cr(iii) With Other Amino Acids: Kineticcontrasting

confidence: 46%

Ligand Sequential Replacement on Chromium(III)–Aqua Complexes by l-Alanine and Other Biological Amino Acids: A Kinetic Perspective

Perez‐Benito

Martinez-Cereza

2018

J. Phys. Chem. A

Self Cite

View full text Add to dashboard Cite

show abstract

“…No use is made of the dependence of ΔH and ΔS on a characteristic of the investigated samples, for example, the composition of alloys, the size of the nanocubes, the geographic location of the habitat of fishes, the degree of oxidation etc. Furthermore, the physical nature of the compensation is not discussed here but includes sources of systematic errors in addition to more fundamental reasons [34] …”

Section: Discussionmentioning

confidence: 99%

Simple Accurate Verification of Enthalpy‐Entropy Compensation and Isoequilibrium Relationship

Griessen

Dam

2021

ChemPhysChem

View full text Add to dashboard Cite

In many experimental investigations of thermodynamic equilibrium or kinetic properties of series of similar reactions it is found that the enthalpies and entropies derived from Van ′t Hoff or Arrhenius plots exhibit a strong linear correlation. The origin of this Enthalpy‐Entropy compensation, which is strongly related to the coalescence tendency of Van ′t Hoff or Arrhenius plots, is not necessarily due to a physical/chemical/biological process. It can also be a merely statistical artefact. A new method, called Combined K‐CQF makes it possible both to quantify the degree of coalescence of experimental Van ‘t Hoff lines and to verify whether or not the Enthalpy‐Entropy Compensation is of a statistical origin at a desired confidence level. The method is universal and can handle data sets with any degree of coalescence of Van ‘t Hoff (or Arrhenius) plots. The new method requires only a standard least square fit of the enthalpyΔH versus entropy ΔS plot to determine the two essential dimensionless parameters K and CQF. The parameter K indicates the position (in inverse temperature) of the coalescence region of Van ‘t Hoff plots and CQF is a quantitative measure of the smallest spread of the Van ‘t Hoff plots. The position of the (K, CQF) couple with respect to universal confidence contours determined from a large number of simulations of random Van ‘t Hoff plots indicates straightforwardly whether or not the ΔH‐ΔS compensation is a statistical artefact.

show abstract

“…There are several reports in the literature that have demonstrated enthalpy-entropy compensation effects for the solubility of drugs in aqueous or non-aqueous co-solvent mixtures. The graph of ΔH S as a function of ΔG S hm at mean harmonic temperature allows us to observe similar mechanisms for the dissolution process according to the tendencies obtained [24,25,27,[31][32][33][34]. Figure 8 shows fully that CLX in the cosolvent system presents nonlinear ΔH S vs ΔG S hm compensation with positive slope in an interval from pure ethanol to 40 % ethanol in water.…”

Section: Enthalpy-entropy Compensation Analysis Of CLXmentioning

confidence: 54%

Thermodynamic analysis of celecoxib in amphiprotic and amphiprotic-aprotic solvent mixtures at several temperatures

Peña

Escalera

Torres

2019

Rev. Colomb. Cienc. Quím. Farm.

View full text Add to dashboard Cite

The solubilities of celecoxib (CLX), a COX-2 selective nonsteroidal anti-inflammatory drug, were determined in water-ethanol and ethanol-ethyl acetate mixtures at several temperatures (288.15-308.15 K). The solubility curves as a function of ethanol ratio were studied at five temperatures, they showed a single maximum located at 50% ethanol-ethyl acetate (δ1 = 22.50 MPa1/2). The measurements of the variation of inherent drug solubility with temperature were used to estimate different thermodynamic parameters, enthalpy, entropy and Gibbs free energy of solution (ΔHS,ΔSS and ΔGShm, respectively). The apparent enthalpies of the solution were a nonlinear function of the ethanol ratio in aqueous mixture. Non-linear enthalpy-entropy compensation analysis was observed indicating different dissolution mechanism with the variation in mixtures composition. The solubility enhancement is entropy driven at water-rich region (0-40% v/v ethanol) and enthalpy controlled at ethanol-rich region (40–100% v/v ethanol), likely due to water-structure loss around nonpolar moieties of the drug and for the ethanol-rich mixtures it is the enthalpy, probably due to the drug better solvation.

show abstract

Enthalpy–Entropy Compensation Effect in Chemical Kinetics and Experimental Errors: A Numerical Simulation Approach

Cited by 29 publications

References 88 publications

Ligand Sequential Replacement on Chromium(III)–Aqua Complexes by l-Alanine and Other Biological Amino Acids: A Kinetic Perspective

Ligand Sequential Replacement on Chromium(III)–Aqua Complexes by l-Alanine and Other Biological Amino Acids: A Kinetic Perspective

Simple Accurate Verification of Enthalpy‐Entropy Compensation and Isoequilibrium Relationship

Thermodynamic analysis of celecoxib in amphiprotic and amphiprotic-aprotic solvent mixtures at several temperatures

Contact Info

Product

Resources

About