ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Several organic compounds like phenanthrene, benzanilide, anisic acid, triphenylene, 2-chloroanthraquinone, hexachlorobenzene, carbazole, 4-iodobenzoic acid, perylene, anthraquinone, as new reference materials for temperature and energy calibration of DTA and DSC apparatuses were studied in the range 300-600 K.
In the present work we studied acridone and thioxanthone by combustion calorimetry of small amounts of substance, by sublimation calorimetry, by differential thermal analysis, and by heat capacity measurements. The thermodynamic quantities derived are as follows: For acridone: [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] For thioxanthone: [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] ΔfusHm = (35.50 ± 0.28) kJ mol−1, Ttp = (487.88 ± 0.02) K. The experimental results permitted us to determine for each molecule its resonance energy and to compare it with the theoretical value. This comparison fits well for acridone, which is planar. The difference observed in the case of thioxanthone shows that this molecule is not planar, in accord with literature structural results. From the experimental enthalpy of atomization of acridone, we determined an enthalpy value for the Cb—N bond. Using the enthalpy contributions previously determined in our laboratory, we found a value for the enthalpy of atomization of thioxanthone in accord with the experimental result. Keywords: thermodynamics; calorimetry; differential thermal analysis; acridone; thioxanthone; enthalpies of combustion, of sublimation, of fusion; resonance energy; enthalpies of atomization, of intramolecular bonds; triple point temperature.
Anthrone, coumarin and phenazine were studied by combustion calorimetry of small amounts of substance, sublimation calorimetry, neat capacity measurements and differential thermal analysis.The thermodynamic quantities derived at 298.15 K allowed us to determine some energy valuez related to molecular structure which enabled us to realize a comparative study for the two isomers: chromone and coumarin, and determine an enthalpy value for some intramolecular chemical bonds in the molecules studied.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.