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The enthalpy of formation of methionine revisited
Author(s) -
Roux María Victoria,
Notario Rafael,
Segura Marta,
Chickos James S.,
Liebman Joel F.
Publication year - 2012
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.2961
Subject(s) - chemistry , enthalpy , enthalpy of sublimation , sublimation (psychology) , standard enthalpy of formation , standard enthalpy change of formation , enthalpy of atomization , thermodynamics , quantum chemical , enthalpy of vaporization , methionine , standard enthalpy of reaction , thermochemical cycle , amino acid , organic chemistry , molecule , biochemistry , psychology , physics , hydrogen production , psychotherapist , hydrogen
Methionine (2‐amino‐4‐(methylthio)butanoic acid) is a sulfur‐containing essential α‐amino acid. Despite its importance, its enthalpy of formation is contentious. From the analysis of its polymorphism confirms that the previously reported calorimetric experiments were made in the temperature interval in which a phase transitions occurs. A new value for the enthalpy of formation is suggested based on these results, as well as G4 quantum chemical calculations and thermochemical estimates. From the analysis of experimental enthalpy of formation measurements, the group increment temperature adjusted enthalpy of sublimation, quantum chemical calculations, and difference quantity derived estimates, our recommended value for the gas phase enthalpy of formation of methionine is –(430 ± 10) kJ·mol −1 . Copyright © 2012 John Wiley & Sons, Ltd.