Matos M Agostinha R, Sousa Clara C S, Miranda Margarida S, Morais Victor M F, Liebman Joel F
Departamento de Química, Faculdade de Ciências da Universidade do Porto, Centro de Investigação em Química, P-4169-007 Porto, Portugal.
J Phys Chem B. 2009 Aug 13;113(32):11216-21. doi: 10.1021/jp9026942.
Condensed phase standard (p degrees = 0.1 MPa) molar enthalpies of formation for coumarin and chromone were derived from the standard molar enthalpies of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The standard molar enthalpies of sublimation, at T = 298.15 K, were measured by Calvet microcalorimetry. Combining these values, the following enthalpies of formation in the gas phase, at T = 298.15 K, were then derived: coumarin, -(163.4 +/- 3.3) kJ x mol(-1), and chromone, -(126.1 +/- 2.5) kJ x mol(-1). The temperatures of fusion, T(fusion), and fusion enthalpies, at T = T(fusion), were also reported. Additionally, theoretical calculations were done using different methods: DFT/B3LYP, MCCM (MC-UT/3 and MC-QCISD/3), and also the more accurate G3MP2 method. Good agreement between experimental and theoretical data was achieved. Some correlations between structure and energy were also made, and the aromaticity of the compounds was evaluated by the nucleus independent chemical shifts (NICS).
香豆素和色酮的凝聚相标准（(p^{\circ}=0.1)MPa）摩尔生成焓是通过在(T = 298.15)K下，用静态弹式燃烧量热法测量的在氧气中的标准摩尔燃烧焓推导得出的。在(T = 298.15)K下的标准摩尔升华焓是用卡尔维微量热法测量的。结合这些值，进而推导出在(T = 298.15)K下气相中的下列生成焓：香豆素，(-(163.4\pm3.3))kJ·mol⁻¹，色酮，(-(126.1\pm2.5))kJ·mol⁻¹。还报道了熔点(T_{fus})以及在(T = T_{fus})时的熔化焓。此外，使用不同方法进行了理论计算：密度泛函理论/B3LYP、多组态微扰理论（MC - UT/3和MC - QCISD/3），以及更精确的G3MP2方法。实验数据和理论数据之间取得了良好的一致性。还建立了一些结构与能量之间的相关性，并通过核独立化学位移（NICS）对化合物的芳香性进行了评估。
