Journal ArticleDOI
Thermochemistry of chromone- and coumarin-3-carboxylic acid
TLDR
In this paper, the standard enthalpies of combustion in oxygen at T = 298.15 K, measured by combustion calorimetry, were derived for all the studied compounds in gas-phase, together with appropriate isodesmic, homodesmic reactions.Abstract:
The standard (po = 0.1 MPa) molar enthalpies of formation in the condensed state of chromone-3-carboxylic acid and coumarin-3-carboxylic acid were derived from the standard molar energies of combustion in oxygen at T = 298.15 K, measured by combustion calorimetry. The standard molar enthalpies of sublimation were obtained by Calvet microcalorimetry. From these values the standard molar enthalpies in the gaseous phase, at T = 298.15 K, were derived. Additionally estimates of the enthalpies of formation, of all the studied compounds in gas-phase, were performed using DFT and other more accurate correlated calculations (MCCM and G3MP2), together with appropriate isodesmic, homodesmic or atomization reactions. There is a reasonable agreement between computational and experimental results.read more
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Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, Vaporization and Fusion Enthalpies From 1880 to 2015. Part 1. C1-C10
TL;DR: A compendium of phase change enthalpies including fusion, vaporization, and sublimation was published in 2010 as mentioned in this paper, which included organic, organometallic, and a few inorganic compounds.
Journal ArticleDOI
A group contribution model for determining the sublimation enthalpy of organic compounds at the standard reference temperature of 298 K
Farhad Gharagheizi,Poorandokht Ilani-Kashkouli,William E. Acree,Amir H. Mohammadi,Deresh Ramjugernath +4 more
TL;DR: In this paper, a group contribution model for determining the sublimation enthalpy of organic compounds at the standard reference temperature of 298 K was proposed, which is the same as the one used in this paper.
Journal ArticleDOI
Experimental and theoretical study of the inclusion complexes of 3-carboxycoumarin acid with β- and 2-hydroxypropyl-β-cyclodextrins.
TL;DR: The association process of a host-guest system, cyclodextrins - 3-carboxycoumarin acid (3CCA) was followed by means of UV-vis, circular dichroism and steady-state fluorescence spectroscopies in buffer solution at pH=1.5 to get information on the stoichiometry, the equilibrium constants and the geometry of the inclusion complexes.
Journal ArticleDOI
Synthesis, characterization, biological and thermal behaviour of Co(II), Ni(II) and Cu(II) complexes with Schiff bases having coumarin moieties
TL;DR: In this paper, a series of Co(II), Ni(II) and Cu(II)-clusters have been synthesized with Schiff bases derived from 5-amino-1,3,4-thiadiazole-2-thiol and 8-formyl-7-hydroxy-4-methylcoumarin.
Journal ArticleDOI
Study on the molecular structure and thermal stability of pyrimidine nucleoside analogs
Xue-jie Wang,Jin-zong You +1 more
TL;DR: In this article, the molecular bond orders of pyrimidines and pyrimidine nucleoside analogs were calculated with an ab initio method from the GAMESS program and four types of thermal decomposition mechanisms were discussed.
References
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TL;DR: In this article, a semi-empirical exchange correlation functional with local spin density, gradient, and exact exchange terms was proposed. But this functional performed significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.
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Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density
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Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen
TL;DR: In this paper, a detailed study of correlation effects in the oxygen atom was conducted, and it was shown that primitive basis sets of primitive Gaussian functions effectively and efficiently describe correlation effects.
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Intermolecular interactions from a natural bond orbital, donor-acceptor viewpoint
Journal ArticleDOI
The influence of polarization functions on molecular orbital hydrogenation energies
P. C. Hariharan,John A. Pople +1 more
TL;DR: In this paper, a split-valence extended gaussian basis set was used to obtain the LCAO-MO-SCF energies of closed shell species with two non-hydrogen atoms.