Theoretical study of gas-phase formation enthalpies and isomerism for 4(5)-nitro-1,2,3-triazole and its N-alkyl derivatives and experimental determination of formation enthalpy for 2-methyl-4-nitro-1,2,3-triazole

In the present work, are calculated the gas formation enthalpies (SE; PM3 and PM6) for tin borates: SnB2O4 and Sn2B2O5. The calculated values are compared with experimental ones, obtained by Knudsen effusion mass spectrometry [3]. It is shown that SE methods, besides their lower computational time consuming can, indeed, provide reliable gas phase formation enthalpy values for inorganic compounds containing heavy metals.

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On the trustability of semi-empirical methods to the calculation of gas phase formation enthalpies of inorganic compounds containing heavy metals: tin borates

10.26434/chemrxiv.5393953 ◽

2017 ◽

Author(s):

Robson de Farias

Keyword(s):

Heavy Metals ◽

Gas Phase ◽

Phase Formation ◽

Inorganic Compounds ◽

Formation Enthalpy ◽

Computational Time ◽

Gas Formation ◽

Formation Enthalpies ◽

Knudsen Effusion Mass Spectrometry ◽

Semi Empirical

In the present work, are calculated the gas formation enthalpies (SE; PM3 and PM6) for tin borates: SnB2O4 and Sn2B2O5. The calculated values are compared with experimental ones, obtained by Knudsen effusion mass spectrometry [3]. It is shown that SE methods, besides their lower computational time consuming can, indeed, provide reliable gas phase formation enthalpy values for inorganic compounds containing heavy metals.

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Unknown Knowns: Case Studies in Uncertainties in the Computation of Thermochemical Parameters

10.26434/chemrxiv.13280471 ◽

2020 ◽

Author(s):

John Simmie

Keyword(s):

Heat Capacity ◽

Gas Phase ◽

Basis Set ◽

Statistical Thermodynamic ◽

Vibrational Modes ◽

Heavy Atoms ◽

New Methods ◽

Formation Enthalpies ◽

Thermochemical Parameters

<div>Both the computation of, and the uncertainties associated, with gas-phase molar formation enthalpies are now quite well established for systems comprised of tens of ‘heavy’ atoms chosen from the commonest elements. The same cannot be said for derived thermochemical quantities such as entropy, heat capacity and an enthalpy function. Whilst the application of well known statistical thermodynamic relations is mostly understood, the determination of the uncertainty with which such values can be obtained has been little studied — apart, that is, for a general protocol devised by Goldsmith et al. [J. Phys. Chem. A, 2012, 116, 9033–9057]. Specific examples from that work are explored here and it is shown that their estimates are overly pessimistic. It is also evident that for some species the calculated thermochemical parameters show very little variation with either the level of theory, or basis set, or treatment of vibrational modes — this renders the inclusion of such species in databases designed to validate new methods of limited value. </div>

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Experimental determination of carbon vs. oxygen regioselectivity in reactions of gas-phase enolate ions

Journal of Physical Organic Chemistry ◽

10.1002/poc.610020505 ◽

1989 ◽

Vol 2 (5) ◽

pp. 389-409 ◽

Cited By ~ 21

Author(s):

Mark D. Brickhouse ◽

Robert R. Squires

Keyword(s):

Experimental Determination ◽

Gas Phase

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Experimental Determination of Dipole Moments of Some Benzamide Derivatives

Zeitschrift für Naturforschung A ◽

10.1515/zna-1998-0807 ◽

1998 ◽

Vol 53 (8) ◽

pp. 684-688

Author(s):

J. Heidt ◽

J. R. Heidt ◽

M. Raciniewskab

Keyword(s):

Excited State ◽

Experimental Determination ◽

Gas Phase ◽

Electronic Absorption ◽

Dipole Moments ◽

Absorption Bands ◽

Excited State Dipole Moments ◽

Benzamide Derivatives

Abstract The excited state dipole moments of some benzamide derivatives are determined. The method of solvent induced shifts of electronic absorption bands in comparison with their positions in the gas phase is used. Some regular trends revealed in the obtained data are discussed. The present results are compared with those available in the literature.

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