Thermochemistry of 6-propyl-2-thiouracil: an experimental and computational study.
Szterner, P.[Piotr], Galvao, T. L. P.[Tiago L.P.], Amaral, L. M. P. F.[Luisa M.P.F.], Silva, M. D. M. C. R. d.[Maria D.M.C. Ribeiro da], Silva, M. A. V. R. d.[Manuel A.V. Ribeiro da]
The standard (po = 0.1 MPa) molar enthalpy of formation of 6-propyl-2-thiouracil was derived from its standard molar energy of combustion, in oxygen, to yield CO2 (g), N2 (g) and H2SO4 a115H2O (l), at T = 298.15 K, measured by rotating bomb combustion calorimetry. The vapor pressures as function of temperature were measured by the Knudsen effusion technique and the standard molar enthalpy of sublimation, om g poundsGcrH , at T = 298.15 K, was derived by the Clausius-Clapeyron equation. These two thermodynamic parameters yielded the standard molar enthalpy of formation, in the gaseous phase, at T = 298.15 K: !V(142.5 !O 1.9) kJ!Pmol-1. This value was compared with estimates obtained from very accurate computational calculations using the G3 and G4 composite methods.
Compounds
#
Formula
Name
1
H2O4S
sulfuric acid
2
CO2
carbon dioxide
3
N2
nitrogen
4
H2O
water
5
O2
oxygen
6
C7H10N2OS
6-propyl-2-thiouracil
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.
Type
Compound-#
Property
Variable
Constraint
Phase
Method
#Points
POMD
6
Vapor or sublimation pressure, kPa ; Liquid
Temperature, K; Liquid
Liquid
Gas
Calculated from knudsen effusion weight loss
12
POMD
6
Vapor or sublimation pressure, kPa ; Liquid
Temperature, K; Liquid
Liquid
Gas
Calculated from knudsen effusion weight loss
11
POMD
6
Vapor or sublimation pressure, kPa ; Liquid
Temperature, K; Liquid
Liquid
Gas
Calculated from knudsen effusion weight loss
12
RXND
6
1
2
3
4
5
Specific internal energy of reaction at constant volume, J/g