bereket dana | Chang Chun University of scicence and technology (original) (raw)
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Papers by bereket dana
arXiv (Cornell University), Apr 19, 2023
arXiv (Cornell University), Nov 15, 2022
The self-association of caffeine, chlorogenic acid and their hetero-association with Methylene Bl... more The self-association of caffeine, chlorogenic acid and their hetero-association with Methylene Blue were studied in aqueous solution by UV/Visible spectrophotometry. The dimerization constants of caffeine and chlorogenic acid analyzed using dimer model at the wavelengths of 272.8 and 324 nm were found to be 565.33 and 1027 M respectively. The heteroassociation constants of methylene blue with caffeine and chlorogenic acid analyzed using BenesiHilde brand approach at the wavelength of 664 nm were found to be 8418 and 14542 M respectively. Thermodynamic parameters such as Gibbs free energy, enthalpy and entropy of dimerization reactions of the compounds were also investigated using Vant’s Hoff equation at the temperature range of 295–301 K for self-association and 295–302 K for hetero-association. The change of enthalpy calculated for caffeine, chlorogenic acid and the complexes of MB-CAF and MBCGA at the temperature of 301 K are –12.86 ± 0.073, –14.24 ± 0.839, 5.12 ± 0.09, and 3.61 ±...
Physica B: Condensed Matter, 2022
arXiv (Cornell University), Apr 19, 2023
arXiv (Cornell University), Nov 15, 2022
The self-association of caffeine, chlorogenic acid and their hetero-association with Methylene Bl... more The self-association of caffeine, chlorogenic acid and their hetero-association with Methylene Blue were studied in aqueous solution by UV/Visible spectrophotometry. The dimerization constants of caffeine and chlorogenic acid analyzed using dimer model at the wavelengths of 272.8 and 324 nm were found to be 565.33 and 1027 M respectively. The heteroassociation constants of methylene blue with caffeine and chlorogenic acid analyzed using BenesiHilde brand approach at the wavelength of 664 nm were found to be 8418 and 14542 M respectively. Thermodynamic parameters such as Gibbs free energy, enthalpy and entropy of dimerization reactions of the compounds were also investigated using Vant’s Hoff equation at the temperature range of 295–301 K for self-association and 295–302 K for hetero-association. The change of enthalpy calculated for caffeine, chlorogenic acid and the complexes of MB-CAF and MBCGA at the temperature of 301 K are –12.86 ± 0.073, –14.24 ± 0.839, 5.12 ± 0.09, and 3.61 ±...
Physica B: Condensed Matter, 2022