Gas-phase standard enthalpies of formation of urea-derived compounds: A quantum-chemical study

Gratzfeld, Dennis; Olzmann, Matthias

doi:10.1016/j.cplett.2017.05.006

Cited by 9 publications

(9 citation statements)

References 34 publications

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“…This value is only 0.4 kJ·mol –1 different from that predicted by isodesmic reactions approach . From isodesmic reactions, the new Δ f H m ° (g) values were also proposed for phenol and urea, and again, these values agree well with the results of recent higher-level calculations. , …”

Section: Introductionsupporting

confidence: 84%

“…Today there are ab initio quantum chemical methods that allow estimating the atomization energy, and therefore the gas-phase enthalpy of formation, with sub-kJ·mol –1 accuracy . However, these methods are currently applicable only to medium-sized and small molecules (less than 10 non-hydrogen atoms). − For large molecules with up to 20 non-hydrogen atoms, the highly reliable data can be obtained using less accurate methods by applying them to isodesmic reactions rather than to atomization energies …”

Section: Introductionmentioning

confidence: 99%

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Aliphatic Amines: A Critical Analysis of the Experimental Enthalpies of Formation by Comparison with Theoretical Calculations

2019

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The accuracy of experimental data on enthalpies of formation and vaporization of aliphatic amines (primary, secondary, and tertiary amines, di-, tri-, and tetramines, and cycloalkylamines) was assessed by theoretical calculations. The gas-phase enthalpies of formation were calculated using the Gaussian 4 (G4) method combined with isodesmic reactions. Three amines, CH 3 NH 2 , CH 3 NHCH 3 , and (CH 3 ) 3 N, were used as the main reference species in the isodesmic reactions; their experimental enthalpies of formation were recently revisited in the Active Thermochemical Tables. The enthalpies of vaporization were estimated by three group additivity and molecular electrostatic potential models and then were used to calculate the enthalpies of formation in the liquid state. When the deviations of experimental values from those provided by the theoretical methods were analyzed, a set of accurate and consistent values of enthalpy of formation of aliphatic amines was recommended for use in thermochemical calculations and as benchmarks for theoretical chemistry.

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Section: Introductionsupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Aliphatic Amines: A Critical Analysis of the Experimental Enthalpies of Formation by Comparison with Theoretical Calculations

2019

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“…So far, various theoretical methods for calculating the enthalpy of formation of compounds have been developed, such as the empirical method and the quantum chemical method. [20][21][22][23][24] Different from these traditional methods, this work predicted the enthalpy of formation of monosubstituted alkanes by using their values of 13 C NMR chemical shift. Its significance is not only to propose a new method to estimate the enthalpy of formation of monosubstituted alkanes, but also to establish a new method to understand the relationship between different properties based on the same molecular structure.…”

Section: F I G U R Ementioning

confidence: 99%

Estimation of the enthalpy of formation for monosubstituted alkanes by ¹³C NMR chemical shift

Tang

2020

J of Physical Organic Chem

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The quantitative relationship between the 13 C nuclear magnetic resonance (NMR) chemical shift and the enthalpy of formation of monosubstituted alkanes was studied, and a new approach for calculating enthalpy of formation was proposed. The experimental values of the enthalpy of formation of 64 monosubstituted alkanes were correlated with the parameters SCS (the sum of chemical shift), P3 (path counts of length three bonds), n (the number of C atoms), h[X] (the contributions of the substituent X to the Δ f H (RX)), and the product of IPI(X) (the interaction potential index) and PEI(R) (the polarizability effect index). The regression results show a good correlation (R = 0.9998, S = 4.5 kJ/mol). Its stability and prediction ability were confirmed by the results of the random sampling method and the leave-one-out method. In this paper, the 13 C NMR chemical shift and the enthalpy of formation of monosubstituted alkanes were associated quantitatively. The significance is not only to propose a new method to estimate the enthalpy of formation of monosubstituted alkanes, but also to establish a new method to understand the relationship between different properties based on a same molecular structure. Moreover, it provides a new approach for calculating a molecular difficult-to-test property parameter by means of another easy-to-test one. K E Y W O R D S chemical shift, enthalpy of formation, monosubstituted alkanes, 13 C NMR

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“…The initial unimolecular decomposition of urea in water was found to yield NH 3 and HCNO. Gratzfeld and Olzmann [11] calculated the enthalpy of formation of all the urea-derived compounds involved in reactions R1 to R7 using high-level CCSD(T)-F12…”

Section: Introductionmentioning

confidence: 99%

Theoretical study of the gas-phase thermal decomposition of urea

Honorien

Fournet²,

Glaude³

et al. 2021

Proceedings of the Combustion Institute

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Gas-phase standard enthalpies of formation of urea-derived compounds: A quantum-chemical study

Cited by 9 publications

References 34 publications

Aliphatic Amines: A Critical Analysis of the Experimental Enthalpies of Formation by Comparison with Theoretical Calculations

Aliphatic Amines: A Critical Analysis of the Experimental Enthalpies of Formation by Comparison with Theoretical Calculations

Estimation of the enthalpy of formation for monosubstituted alkanes by ¹³C NMR chemical shift

Theoretical study of the gas-phase thermal decomposition of urea

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Gas-phase standard enthalpies of formation of urea-derived compounds: A quantum-chemical study

Cited by 9 publications

References 34 publications

Aliphatic Amines: A Critical Analysis of the Experimental Enthalpies of Formation by Comparison with Theoretical Calculations

Aliphatic Amines: A Critical Analysis of the Experimental Enthalpies of Formation by Comparison with Theoretical Calculations

Estimation of the enthalpy of formation for monosubstituted alkanes by 13C NMR chemical shift

Theoretical study of the gas-phase thermal decomposition of urea

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Estimation of the enthalpy of formation for monosubstituted alkanes by ¹³C NMR chemical shift