Thermochemistry of 6-propyl-2-thiouracil: An experimental and computational study

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Piotr Szterner (Author) Other; Tiago L P Galvao (Author) Other; Luisa M P F Amaral (Author) Other; Maria D M C R Ribeiro da Silva (Author) FCUP; Manuel A V R Ribeiro da Silva (Author) Other

Journal

Title: Thermochimica Acta

Vol. 588

Pages: 68-74

ISSN: 0040-6031

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 8 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-009-HJ7

DOI: 10.1016/j.tca.2014.04.018

Abstract (EN): The standard (p(o) = 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), N-2 (g) and H2SO4 center dot 115H(2)O (I), 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, Delta H-g(cr)m(o). 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: -(142.5 +/- 1.9) kJ mol(-1). This value was compared with estimates obtained from very accurate computational calculations using the G3 and G4 composite methods.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7