Étude thermodynamique de l'acridone et de la thioxanthone

Sabbah, Raphaël; Watik, Lahcen El

doi:10.1139/v92-005

Cited by 20 publications

(11 citation statements)

References 5 publications

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“…This signifies that benzene rings are bent and TX is nonplanar. Further, the earlier calorimetry study also substantiates the slight nonplanarity in the TX structure.…”

Section: Resultssupporting

confidence: 58%

Time-Resolved Resonance Raman Spectroscopic Studies on the Triplet Excited State of Thioxanthone

Pandey

Umapathy

2011

J. Phys. Chem. A

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Thioxanthone has been investigated extensively owing to its unique photochemical and photophysical applications and its solvatochromic behavior. Here, we report the time-resolved resonance Raman studies on the structure of the lowest triplet excited state of thioxanthone in carbon tetrachloride. In addition, FT-IR and FT-Raman techniques have been used to study the vibrational structure in the ground state. To corroborate the experimental findings, density functional theory calculations have been carried out. Isotopic calculations and normal coordinate analysis have been used to help in assigning the observed bands to Raman vibrational modes. Structural information derived from this study is expected to help in better understanding the triplet state photochemistry of thioxanthone.

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“…This signifies that benzene rings are bent and TX is nonplanar. Further, the earlier calorimetry study also substantiates the slight nonplanarity in the TX structure.…”

Section: Resultssupporting

confidence: 58%

Time-Resolved Resonance Raman Spectroscopic Studies on the Triplet Excited State of Thioxanthone

Pandey

Umapathy

2011

J. Phys. Chem. A

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“…The standard enthalpies of formation predicted at the PM3 level are always the lowest, while those obtained at the HF and DFT levels are higher and are comparable. The experimental value of Δ f,298 H ° is available only for gaseous 9(10 H )-acridinone and is equal to 34.6 kJ/mol . This value is much lower than the ones obtained at the DFT, HF, or even PM3 levels.…”

Section: Resultsmentioning

confidence: 76%

“…It is difficult to assess the reasons for the discrepancies between the theoretical and experimental values of Δ f,298 H °. Sabbah and El Watik determined the heat of combustion of 9(10 H )-acridinone, and the standard enthalpy of formation was obtained using basic thermodynamic relations on the assumption that the products of combustion are CO 2 (gaseous), H 2 O (liquid), and N 2 (gaseous) . This last product may be uncertain, and the above assumption may be the reason for the observed discrepancies.…”

Section: Resultsmentioning

confidence: 99%

Structure, Properties, Thermodynamics, and Isomerization Ability of 9-Acridinones

et al. 2002

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Acridinone and its 13 derivatives were examined at the semiempirical (MNDO, AM1, PM3, MNDO/ d), ab initio (HF, MP2), and density functional (DFT) levels of theory with the 6-31G**, 6-31++G**, and 6-311G** basis sets to predict structure, enthalpies and free enthalpies of formation, entropies, HOMO and LUMO energies, and dipole moments. The possibilities of some of the compounds occurring in more than one tautomeric (isomeric) form were further considered. The behavior of 9-acridinones and their features, which may be useful if the compounds are to be used as analytical spectral indicators or fragments of fluorescent or chemiluminescent labels, are also briefly discussed.

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“…As it was said above, some experimental studies have been carried out in the past for some sulfur heterocycles. In the case of thioxanthone, Sabbah et al performed a detailed thermodynamic study employing combustion calorimetry, sublimation calorimetry, differential thermal analysis, and heat capacity measurements. They reported an experimental value of the standard molar enthalpy of formation in the gas phase, Δ f H m o (g) = (94.3 ± 3.6) kJ·mol −1 , which is in agreement with our experimental value, considering the uncertainty associated.…”

Section: Resultsmentioning

confidence: 99%

Experimental and Computational Studies on the Structural and Thermodynamic Properties of Two Sulfur Heterocyclic Keto Compounds

et al. 2010

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The present work reports the standard (p°) 0.1 MPa) molar enthalpies of formation in the gaseous phase of thioxanthone, (91.9 ( 2.4) kJ • mol -1 , and tetrahydrothio-γ-pyrone, (-164.6 ( 2.0) kJ • mol -1 , at T ) 298.15 K, derived from their standard molar energies of combustion and standard molar enthalpies of sublimation, measured by rotating-bomb combustion calorimetry and by the vacuum drop microcalorimetric technique, respectively. For comparison purposes, we performed additional standard ab initio molecular orbital calculations, using the G3(MP2)//B3LYP composite procedure, which were used for the calculation of the enthalpies of several homodesmotic reactions, allowing us to extract the standard molar enthalpies of formation, in the gaseous phase, of the two heterocycles considered in this work. The calculated results are in excellent agreement with the experimental data. The three-dimensional structure of the crystal tetrahydrothio-γ-pyrone was also determined by X-ray crystallography.

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Étude thermodynamique de l'acridone et de la thioxanthone

Cited by 20 publications

References 5 publications

Time-Resolved Resonance Raman Spectroscopic Studies on the Triplet Excited State of Thioxanthone

Time-Resolved Resonance Raman Spectroscopic Studies on the Triplet Excited State of Thioxanthone

Structure, Properties, Thermodynamics, and Isomerization Ability of 9-Acridinones

Experimental and Computational Studies on the Structural and Thermodynamic Properties of Two Sulfur Heterocyclic Keto Compounds

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