Title
Energetic studies of urea derivatives: Standard molar enthalpy of formation of 3,4,4′-trichlorocarbanilide
Date Issued
01 April 2010
Access level
metadata only access
Resource Type
journal article
Author(s)
Ribeiro da Silva M.d.D.M.C.
Ribeiro da Silva M.A.V.
Freitas V.L.S.
Roux M.V.
Jiménez P.
Cabildo P.
Claramunt R.M.
Pinilla E.
Rosario Torres M.
Elguero J.
Consejo Superior de Investigaciones Científicas
Abstract
Thermochemical and thermophysical studies have been carried out for crystalline 3,4,4′-trichlorocarbanilide. The standard (p° = 0.1 MPa) molar enthalpy of formation, at T = 298.15 K, for the crystalline 3,4,4′-trichlorocarbanilide (TCC) was experimentally determined using rotating-bomb combustion calorimetry, as -(234.6 ± 8.3) kJ · mol-1. The standard enthalpy of sublimation, at the reference temperature of 298.15 K, was measured by the vacuum drop microcalorimetric technique, using a High Temperature Calvet Microcalorimeter as (182.1 ± 1.7) kJ · mol-1. These two thermochemical parameters yielded the standard molar enthalpy of formation of the studied compound, in the gaseous phase, at T = 298.15 K, as -(52.5 ± 8.5) kJ · mol-1. This parameter was also calculated by computational thermochemistry at M05-2X/6-311++G** and B3LYP/6-311++G(3df, 2p) levels, with a deviation less than 4.5 kJ · mol-1 from experimental value. Moreover, the thermophysical study was made by differential scanning calorimetry, DSC, over the temperature interval between T = 263 K and its onset fusion temperature, T = (527.5 ± 0.4) K. A solid-solid phase transition was found at T = (428 ± 1) K, with the enthalpy of transition of (6.1 ± 0.1) kJ · mol-1. The X-ray crystal structure of TCC was determined and the three-centred N-H⋯O{double bond, long}C hydrogen bonds present analyzed. © 2009 Elsevier Ltd. All rights reserved.
Start page
536
End page
544
Volume
42
Issue
4
Language
English
OCDE Knowledge area
Química
Subjects
Scopus EID
2-s2.0-75849137198
Source
Journal of Chemical Thermodynamics
ISSN of the container
10963626
Sponsor(s)
Thanks are due to Gabinete de Relações Internacionais da Ciência e do Ensino Superior (GRICES), Lisbon, Portugal, and Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain for a joint research project GRICES/CSIC. Thanks are due to Fundação para a Ciência e a Tecnologia, F.C.T. , Lisbon, Portugal, and to FEDER for financial support to Centro de Investigação em Química da Universidade do Porto (CIQ-U.P.). V.L.S.F. thanks Faculdade de Ciências for a research grant. The Spanish co-authors gratefully acknowledged the support of DGES/MEC , CTQ 2006-10178/BQU , CTQ2007-62113 , CTQ 2007-60895/BQU .
Sources of information:
Directorio de Producción Científica
Scopus