Journal of Chemical Thermodynamics, Vol.57, 454-460, 2013
The enthalpies of formation of alkyl carbamates: Experimental and computational redetermination
In the present work, a redetermination of thermochemical data of methyl carbamate and ethyl carbamate was performed by both experimental and computational techniques. Their gas-phase standard (p degrees = 0.1 MPa) molar enthalpies of formation, Delta H-f degrees(m) m (g), at T = 298.15 K, were derived from the standard molar enthalpies of formation, in the crystalline phase, Delta H-f degrees(m)(cr), and from the standard molar enthalpies of sublimation, Delta H-g(cr)degrees(m) at T = 298.15 K, measured, respectively, by static bomb combustion calorimetry and high temperature Calvet microcalorimetry. The experimental results were compared with computational data, calculated at the G3(MP2)//B3LYP level, as well as with values reported in the literature. At the B3LYP/6-31G(d) level of theory, the molecular structure of both carbamates was obtained. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords:Enthalpy of combustion;Enthalpy of sublimation;Enthalpy of formation;Combustion calorimetry;High temperature Calvet microcalorimetry;G3(MP2)//B3LYP calculations;Methyl carbamate;Ethyl carbamate