Energetics of neutral and deprotonated (Z)-cinnamic acid
We have performed a study of structural, thermochemical and thermophysical properties of the (Z)-cinnamic acid neutral molecule and its corresponding oxyanion (formed by deprotonation of the carboxylic group). The thermophysical study (heat capacities, temperature and enthalpy of fusion) was made by...
Guardado en:
| Autor principal: | |
|---|---|
| Publicado: |
2016
|
| Materias: | |
| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219614_v95_n_p195_Davalos http://hdl.handle.net/20.500.12110/paper_00219614_v95_n_p195_Davalos |
| Aporte de: |
| id |
paper:paper_00219614_v95_n_p195_Davalos |
|---|---|
| record_format |
dspace |
| spelling |
paper:paper_00219614_v95_n_p195_Davalos2023-06-08T14:44:41Z Energetics of neutral and deprotonated (Z)-cinnamic acid Erra Balsells, Rosa (Z)-cinnamic acid B3LYP EKM Enthalpies of formation G3 G4 Gas-phase acidity Computation theory Density functional theory Gases Mass spectrometry Molecules Positive ions Solutions Thermodynamic properties B3LYP Cinnamic acids EKM Enthalpies of formation G3 G4 Gas-phase acidities Enthalpy We have performed a study of structural, thermochemical and thermophysical properties of the (Z)-cinnamic acid neutral molecule and its corresponding oxyanion (formed by deprotonation of the carboxylic group). The thermophysical study (heat capacities, temperature and enthalpy of fusion) was made by DSC. The following intrinsic (gas-phase) thermochemical magnitudes have been experimentally determined: (i) standard enthalpy of formation, at T = 298.15 K, of the neutral molecule, ΔfHm0(g) = (-215.5 ± 3.2) kJ · mol-1, by combustion calorimetry and by the Knudsen effusion technique, (ii) deprotonation enthalpy, ΔacidH0(g) = (1416.4 ± 8.8) kJ · mol-1 and acidity, GA = (1386.7 ± 8.8) kJ · mol-1, by the EKM method using ESI-TQ Mass Spectrometry. From these results we have also derived the enthalpy of formation of the oxyanion, ΔfHm0(oxyanion, g) = (-303.5 ± 9.4) kJ · mol-1. A computational study, through density functional calculations at the B3LYP/6-311++G(d,p) level of theory, was used to check the good consistency of the experimental results. The global results show that (Z)-cinnamic acid is significantly less stable than the corresponding (E)-isomer, which can be related to the greater acidity of the (Z)-form found in both the gas and aqueous solution phases. © 2015 Elsevier Ltd. All rights reserved. Fil:Erra-Balsells, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2016 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219614_v95_n_p195_Davalos http://hdl.handle.net/20.500.12110/paper_00219614_v95_n_p195_Davalos |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
(Z)-cinnamic acid B3LYP EKM Enthalpies of formation G3 G4 Gas-phase acidity Computation theory Density functional theory Gases Mass spectrometry Molecules Positive ions Solutions Thermodynamic properties B3LYP Cinnamic acids EKM Enthalpies of formation G3 G4 Gas-phase acidities Enthalpy |
| spellingShingle |
(Z)-cinnamic acid B3LYP EKM Enthalpies of formation G3 G4 Gas-phase acidity Computation theory Density functional theory Gases Mass spectrometry Molecules Positive ions Solutions Thermodynamic properties B3LYP Cinnamic acids EKM Enthalpies of formation G3 G4 Gas-phase acidities Enthalpy Erra Balsells, Rosa Energetics of neutral and deprotonated (Z)-cinnamic acid |
| topic_facet |
(Z)-cinnamic acid B3LYP EKM Enthalpies of formation G3 G4 Gas-phase acidity Computation theory Density functional theory Gases Mass spectrometry Molecules Positive ions Solutions Thermodynamic properties B3LYP Cinnamic acids EKM Enthalpies of formation G3 G4 Gas-phase acidities Enthalpy |
| description |
We have performed a study of structural, thermochemical and thermophysical properties of the (Z)-cinnamic acid neutral molecule and its corresponding oxyanion (formed by deprotonation of the carboxylic group). The thermophysical study (heat capacities, temperature and enthalpy of fusion) was made by DSC. The following intrinsic (gas-phase) thermochemical magnitudes have been experimentally determined: (i) standard enthalpy of formation, at T = 298.15 K, of the neutral molecule, ΔfHm0(g) = (-215.5 ± 3.2) kJ · mol-1, by combustion calorimetry and by the Knudsen effusion technique, (ii) deprotonation enthalpy, ΔacidH0(g) = (1416.4 ± 8.8) kJ · mol-1 and acidity, GA = (1386.7 ± 8.8) kJ · mol-1, by the EKM method using ESI-TQ Mass Spectrometry. From these results we have also derived the enthalpy of formation of the oxyanion, ΔfHm0(oxyanion, g) = (-303.5 ± 9.4) kJ · mol-1. A computational study, through density functional calculations at the B3LYP/6-311++G(d,p) level of theory, was used to check the good consistency of the experimental results. The global results show that (Z)-cinnamic acid is significantly less stable than the corresponding (E)-isomer, which can be related to the greater acidity of the (Z)-form found in both the gas and aqueous solution phases. © 2015 Elsevier Ltd. All rights reserved. |
| author |
Erra Balsells, Rosa |
| author_facet |
Erra Balsells, Rosa |
| author_sort |
Erra Balsells, Rosa |
| title |
Energetics of neutral and deprotonated (Z)-cinnamic acid |
| title_short |
Energetics of neutral and deprotonated (Z)-cinnamic acid |
| title_full |
Energetics of neutral and deprotonated (Z)-cinnamic acid |
| title_fullStr |
Energetics of neutral and deprotonated (Z)-cinnamic acid |
| title_full_unstemmed |
Energetics of neutral and deprotonated (Z)-cinnamic acid |
| title_sort |
energetics of neutral and deprotonated (z)-cinnamic acid |
| publishDate |
2016 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219614_v95_n_p195_Davalos http://hdl.handle.net/20.500.12110/paper_00219614_v95_n_p195_Davalos |
| work_keys_str_mv |
AT errabalsellsrosa energeticsofneutralanddeprotonatedzcinnamicacid |
| _version_ |
1768541925144526848 |