Log in

Relevant bibliographies by topics / Isodesmic reactions / Journal articles

To see the other types of publications on this topic, follow the link: Isodesmic reactions.

Journal articles on the topic 'Isodesmic reactions'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Isodesmic reactions.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Ponomarev, D. A., and V. V. Takhistov. "What are Isodesmic Reactions?" Journal of Chemical Education 74, no. 2 (1997): 201. http://dx.doi.org/10.1021/ed074p201.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Su, Xin Fang. "Density Functional Studies on the Standard Heats of Formation for Nitroaromatic Molecules." Advanced Materials Research 1095 (March 2015): 415–18. http://dx.doi.org/10.4028/www.scientific.net/amr.1095.415.

Full text

Abstract:

The standard heats of formation for 12 nitroaromatic molecules in gas at 298 K were calculated at B3P86/6-311G** levels using different isodesmic reactions. Comparison between the computational results and the experimental values reveals that using methane as reference compound to design isodesmic reaction is able to predict satisfactory results of heats of formation for ortho-substituted nitroaromatic molecules; however, using benzene as reference compound is able to give agreement with experimental data for meta-substituted and para-substituted nitroaromatic molecules.

APA, Harvard, Vancouver, ISO, and other styles

3

Takhistov, V. V., and D. A. Ponomarev. "Isodesmic reactions and thermochemistry of ions." Organic Mass Spectrometry 29, no. 8 (1994): 395–412. http://dx.doi.org/10.1002/oms.1210290802.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Fortunelli, Alessandro, and Massimo Selmi. "Density functional calculations on hydrocarbon isodesmic reactions." Chemical Physics Letters 223, no. 4 (1994): 390–96. http://dx.doi.org/10.1016/0009-2614(94)00459-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Bhawal, Benjamin N., and Bill Morandi. "Isodesmic Reactions in Catalysis - Only the Beginning?" Israel Journal of Chemistry 58, no. 1-2 (2017): 94–103. http://dx.doi.org/10.1002/ijch.201700116.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Chan, Bun, and Amir Karton. "Polycyclic aromatic hydrocarbons: from small molecules through nano-sized species towards bulk graphene." Physical Chemistry Chemical Physics 23, no. 32 (2021): 17713–23. http://dx.doi.org/10.1039/d1cp01659h.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Parker, Vernon D., Kishan L. Handoo, Frode Roness, and Mats Tilset. "Electrode potentials and the thermodynamics of isodesmic reactions." Journal of the American Chemical Society 113, no. 20 (1991): 7493–98. http://dx.doi.org/10.1021/ja00020a007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

McAdoo, David J. "Comment on ‘isodesmic reactions and thermochemistry of ions’." Journal of Mass Spectrometry 30, no. 2 (1995): 388–89. http://dx.doi.org/10.1002/jms.1190300225.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

TAKHISTOV, V. V., and D. A. PONOMAREV. "ChemInform Abstract: Isodesmic Reactions and Thermochemistry of Ions." ChemInform 26, no. 3 (2010): no. http://dx.doi.org/10.1002/chin.199503319.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Exner, Otto, and Stanislav Böhm. "Resonance Energy in Benzene Derivatives with a Variable Functional Group." Collection of Czechoslovak Chemical Communications 66, no. 11 (2001): 1623–37. http://dx.doi.org/10.1135/cccc20011623.

Full text

Abstract:

Three isodesmic reactions were investigated in which a variable substituent is transferred from a saturated to an unsaturated hydrocarbon residue: ethane → ethene, methane → benzene, ethane → benzene. Their reaction energies could serve as a measure of substituent resonance ability. They were calculated for 31 substituents by the density functional theory (DFT) at the B3LYP/6-311+G(d,p) level, and served as a model for systematic comparison of the DFT energies and experimental enthalpies of formation ∆fH°(298). It turned out that calculations at this level are more reliable than experiments; t

APA, Harvard, Vancouver, ISO, and other styles

11

McAdoo, David. "Comment: Further comments on “Isodesmic reactions and thermochemistry of ions”." European Journal of Mass Spectrometry 1, no. 1 (1995): 409. http://dx.doi.org/10.1255/ejms.97.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Hyman, Arthur S., Liina H. Ladon, and Joel F. Liebman. "The entropy term in isodesmic, association, and conformational equilibration reactions." Structural Chemistry 5, no. 6 (1994): 399–401. http://dx.doi.org/10.1007/bf02252898.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Yuan, Bingxin, and Zheng Duan. "Catalytic Deoxygenation of Phosphine Oxides via Mild Successive Isodesmic Reactions." Chinese Journal of Organic Chemistry 43, no. 10 (2023): 3666. http://dx.doi.org/10.6023/cjoc202300057.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Knyazev, Vadim D. "Isodesmic Reactions for Transition States: Reactions of Cl Atoms with Methane and Halogenated Methanes." Journal of Physical Chemistry A 107, no. 50 (2003): 11082–91. http://dx.doi.org/10.1021/jp036281p.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

GOLOVIN, A. V., D. A. PONOMAREV, and V. V. TAKHISTOV. "THERMOCHEMISTRY OF ORGANIC, HETEROORGANIC, AND INORGANIC MOLECULES AND THEIR FRAGMENTS: "QUANTUM-CHEMICAL CALCULATIONS OF THERMOCHEMICAL PARAMETERS: MOLECULES AND THEIR FRAGMENTS"." Journal of Theoretical and Computational Chemistry 09, supp01 (2010): 125–53. http://dx.doi.org/10.1142/s0219633610005529.

Full text

Abstract:

Analysis of theoretical enthalpies of formation for about 300 molecules and their fragments (free radicals, biradicals, and ions) was performed to show that the results of semiempirical, DFT, and ab initio methods must be taken with great caution. A brief review of the authors' alternative empirical methodologies for calculation of enthalpies of formation for molecules (enthalpic shift procedure) and free radicals (enthalpies of isodesmic reactions) is given.

APA, Harvard, Vancouver, ISO, and other styles

16

Armstrong, D. A., W. L. Waltz, and A. Rauk. "Carbonate radical anion — Thermochemistry." Canadian Journal of Chemistry 84, no. 12 (2006): 1614–19. http://dx.doi.org/10.1139/v06-168.

Full text

Abstract:

High level ab initio calculations along with isodesmic reactions have been used to derive a set of self-consistent free energies of formation for carbonate and nitrate species in the gas phase and in aqueous solution. The results show that HCO3· is a strong acid, pKa = –4.1, and that E°(CO3·–/CO32) = 1.23 ± 0.15 V.Key words: carbonate radical anion, theoretical, thermochemistry, acidity, reduction potentials.

APA, Harvard, Vancouver, ISO, and other styles

17

MacLennan, Martin T., та Katherine Valenta Darvesh. "Theoretical evidence for P—S and P—N pπ—pπ bonding within the heterocyclopentadienyl framework". Canadian Journal of Chemistry 73, № 4 (1995): 544–49. http://dx.doi.org/10.1139/v95-070.

Full text

Abstract:

SCF and Møller–Plesset calculations have been carried out for systems containing P—S and P—N pπ—pπ bonds: namely, the 1,3,2-dithiaphospholium cation, the 1,3,2-diazaphospholium cation, and the 1,3,2-azathiaphospholium cation. The computed geometries are reported, along with Mulliken atomic charges and selected vibrational frequencies. ΔH0 values for heterolytic P—H bond dissociation and for isodesmic bond separation reactions provide information on the energetics and stabilization of the P—S and P—N pπ—pπ bonds. Keywords: SCF and MP2 calculations, third period pπ—pπ bonding, bond separation re

APA, Harvard, Vancouver, ISO, and other styles

18

Fabian, Walter. "Gas Phase Basicity of Substituted Benzaldehydes and Methylbenzoates.A Semiempirical Molecular Orbital Study." Zeitschrift für Naturforschung A 43, no. 1 (1988): 85–90. http://dx.doi.org/10.1515/zna-1988-0113.

Full text

Abstract:

AbstractThe semiempirical AM1 method is used to calculate relative proton affinities of a series of meta-and para-substituted benzaldehydes and methylbenzoates. Close agreement between the results of these calculations and experimental relative gas phase basicities could be obtained. The influence of a substituent on the stability of both neutral as well as protonated forms is estimated via isodesmic reactions. In any case the influence of a substituent is most pronounced in the protonated carbonyl compound. The contribution of the inductive/field effect of a substituent is approximated by the

APA, Harvard, Vancouver, ISO, and other styles

19

Ginsburg, Jack Leon, Richard Francis Langler, Raj Kumar Raheja, and Laura Precedo. "A MNDO study of planar thioacyl-substituted carbocations." Canadian Journal of Chemistry 70, no. 1 (1992): 111–15. http://dx.doi.org/10.1139/v92-019.

Full text

Abstract:

Relative gas phase stabilities of pairs of planar regioisomeric thioacyl-substituted carbocations have been calculated using the MNDO method. These systems are stabilized by good π donors. The role of S π-electron population as a gauge of substituent effects is examined. Similar results were obtained using isodesmic reactions to gauge substituent effects. Results of this and earlier studies are consistent with the resonance saturation effect. Keywords: semiempirical calculations, carbonium ions.

APA, Harvard, Vancouver, ISO, and other styles

20

El-Alali, Abdullah, Ali A. Marashdeh, and Salim M. Khalil. "A Theoretical Study of Substituted Stepwise Fluorinated Cyclopropanone Keto-Enol System." Zeitschrift für Naturforschung A 58, no. 12 (2003): 749–55. http://dx.doi.org/10.1515/zna-2003-1211.

Full text

Abstract:

MINDO-Forces calculations have been performed with complete optimization of the geometries on stepwise fluorinated cyclopropanones and their enols. Increase in the number of fluorine atoms causes destabilization of cyclopropanone. Perfluorinated enol was found to be present in substantial concentration, as was mentioned in previous work. This is supported by calculations of Gibbs free energies and isodesmic reactions. Geometrical parameters, heats of formation, electron densities, dipole moments and orbital energies (HOMO-LUMO) are reported.

APA, Harvard, Vancouver, ISO, and other styles

21

Ventura, Oscar N., Raúl E. Cachau, and Martina Kieninger. "Density functional and coupled-cluster calculations of isodesmic reactions involving fluorine oxides." Chemical Physics Letters 301, no. 3-4 (1999): 331–35. http://dx.doi.org/10.1016/s0009-2614(99)00032-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Knyazev, Vadim D. "Computational Study of the Reactions of H Atoms with Chlorinated Alkanes. Isodesmic Reactions for Transition States." Journal of Physical Chemistry A 106, no. 47 (2002): 11603–15. http://dx.doi.org/10.1021/jp026313t.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Khalil, Salim M. "A DFT Study on the Stepwise Fluorinated Methylenecyclopropane ⇋ 1-Methylcyclopropene System." Zeitschrift für Naturforschung A 63, no. 1-2 (2008): 42–48. http://dx.doi.org/10.1515/zna-2008-1-207.

Full text

Abstract:

Density functional theory (DFT) calculations have been performed to calculate the optimized geometries of stepwise fluorinated methylenecyclopropanes and 1-methylcyclopropenes. Increasing the number of fluorine atoms caused a destabilization of methylenecycopropane. Perfluorinated 1-methylcyclopropene was found to be present in substantial concentration. This is supported by calculations of the Gibbs free energy, isodesmic reactions and orbital energies (HOMO-LUMO). These results are compared with the fluorinated cyclopropanes keto-enol system. Enthalpies, entropies and dipole moments are repo

APA, Harvard, Vancouver, ISO, and other styles

24

Su, Xin Fang, Jing Hua Wei, and Hai Ying Wu. "The Standard Enthalpies of Formation of Energetic 4,5-dinitroimidazole derivatives: A Theoretical Study." Advanced Materials Research 774-776 (September 2013): 484–87. http://dx.doi.org/10.4028/www.scientific.net/amr.774-776.484.

Full text

Abstract:

The standard enthalpies of formation for 7 derivatives of 4,5-dinitroimidazole in gas at 298 K were determined using isodesmic reactions at B3LYP/6-311G** and B3P86/6-311G** levels. The results indicate that the substitution of nitro group can increase the enthalpies of formation. The more the number of nitro group, the higher the enthalpies of formation. The standard enthalpies of formation of –NO2 and –CH3 substitution compounds on N atom are larger than corresponding ones on C atom.

APA, Harvard, Vancouver, ISO, and other styles

25

Salim, Bareehan M., and Salim M. Khalil. "MINDO-Forces Study on Substituted Nitromethane ⇋ aci-Nitromethane Tautomerism." Zeitschrift für Naturforschung A 60, no. 1-2 (2005): 47–53. http://dx.doi.org/10.1515/zna-2005-1-208.

Full text

Abstract:

MINDO-Forces calculations with complete geometry optimization have been performed on nitromethane, aci-nitromethane and X-substituted nitromethane and aci-nitromethane (X = F, OH, NH2, CH3, CN, CF3, NO2, CHO). It is found that nitromethane is more stable than aci-nitromethane by 9.337 kcal/mol. This agrees with theoretical calculations. Thermodynamically, substituted aci-nitro tautomers are more stable than the corresponding nitromethane, except in case of the substituent F. Geometrical parameters, heats of formation, electron densities, Gibbs free energies and isodesmic reactions are reported

APA, Harvard, Vancouver, ISO, and other styles

26

Takhistov, V., and D. Ponomarev. "Comment: A Reply to the comment on “Isodesmic reactions and thermochemistry of ions”." European Journal of Mass Spectrometry 1, no. 1 (1995): 107. http://dx.doi.org/10.1255/ejms.143.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Aissani, Amin Mohamed, James Clayton Baum, Richard Francis Langler, and Jack Leon Ginsburg. "An MNDO study of substituent effects in carbocations: the unimportance of inductive effects." Canadian Journal of Chemistry 64, no. 3 (1986): 532–38. http://dx.doi.org/10.1139/v86-085.

Full text

Abstract:

Stabilization effects for both saturated and unsaturated substituents were examined using MNDO calculations. (By "saturated substituents" we mean to imply that the substituent is attached to C+ by sp3 carbon, whether or not the substituent has a site of unsaturation at some point remote from the carbocationic center.) Relative gas phase stabilities of regioisomeric carbocations have been calculated. For simple groups, directly bound to [Formula: see text], π donation, σ donation, and polarization effects are found to be important. Saturated-substituent stabilization effects are examined by mea

APA, Harvard, Vancouver, ISO, and other styles

28

Knyazev, Vadim D. "Reactivity Extrapolation from Small to Large Molecular Systems via Isodesmic Reactions for Transition States." Journal of Physical Chemistry A 108, no. 48 (2004): 10714–22. http://dx.doi.org/10.1021/jp046953r.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Slanina, Zdeněk. "Thermodynamics of some model reactions useful for understanding theoretical background of correlation analysis." Collection of Czechoslovak Chemical Communications 55, no. 1 (1990): 32–41. http://dx.doi.org/10.1135/cccc19900032.

Full text

Abstract:

Six isodesmic gas-phase reactions have been studied out of which three reactions represent a redistribution of two methyl substituents and the other three represent a redistribution of two chloro substituents between two benzene nuclei. The thermodynamics of these reactions has been evaluated on the basis of the partition functions and observed heats of formation at room temperature. The partition functions have been constructed with the help of observed structural and vibrational data. If the internal rotation was present, the frequence of the corresponding torsional vibrational mode has been

APA, Harvard, Vancouver, ISO, and other styles

30

Böhm, Stanislav, and Otto Exner. "Revision of the Dual-Substituent-Parameter Treatment; Reaction Series with a Donor Reaction Centre." Collection of Czechoslovak Chemical Communications 72, no. 8 (2007): 1158–76. http://dx.doi.org/10.1135/cccc20071158.

Full text

Abstract:

The dual-substituent-parameter (DSP) treatment was challenged previously as not generally valid. Just in the fundamental reaction, dissociation of 4-substituted benzoic acids and in similar reactions, DPS does not hold for acceptor substituents because the constant reaction centre is itself an acceptor. In this communication, the reverse case was examined, i.e., a reaction series with a donor reaction centre: basicity and acidity of 4-substituted anilines, and acidity of 4-substituted phenols. The reaction energies were calculated for 19 common substituents at the level B3LYP/6-311+G(d,p)//B3L

APA, Harvard, Vancouver, ISO, and other styles

31

Armstrong, D. A., D. Yu та A. Rauk. "Oxidative damage to the glycyl α-carbon site in proteins: an ab initio study of the C—H bond dissociation energy and the reduction potential of the C-centered radical". Canadian Journal of Chemistry 74, № 6 (1996): 1192–99. http://dx.doi.org/10.1139/v96-134.

Full text

Abstract:

The C—H bond dissociation energies (DC—H) of a series of model glycyl proteins were derived from selected isodesmic reactions based on high level ab initio calculations. At 298 K, the recommended values of DC—H, in kJ mol−1 are: NH2CH2CHO, 308; NH2CH2C(O)NH2, 336; HC(O)NHCH2CHO, 331; HC(O)NHCH2C(O)NH2, 350; CH3C(O)NHCH2C(O)NH2, 347; HC(O)NHCH2C(O)NHCH3, 349; and CH3C(O)NHCH2C(O)NHCH3, 346. The average of the last four values, 348 kJ mol−1, is the predicted bond dissociation energy of the α-C—H bond of a glycyl protein. The reduction potential in aqueous medium at 298 K and pH 7 for the process

APA, Harvard, Vancouver, ISO, and other styles

32

Rozhenko, Alexander B., Yuliia S. Horbenko, Andrii A. Kyrylchuk, et al. "Stable Carbenes as Structural Components of Partially Saturated Sulfur-Containing Heterocycles." Molecules 27, no. 5 (2022): 1458. http://dx.doi.org/10.3390/molecules27051458.

Full text

Abstract:

Recently, an unusual elongation of the C-S bond was observed experimentally for some sulfur-containing heterocycles. Using a superior ab initio (SCS-MP2/cc-pVTZ) level of theory, we showed that the phenomenon can be explained by a contribution of a donor–acceptor adduct of a carbene with an unsaturated ligand. One may achieve further elongation of the C-S bond, eventually turning it to a coordinate one, by increasing the stability of each part of the system as, e.g., in the utmost case of spiro adducts with Arduengo carbenes. The effect of carbene stability was quantified by employing the isod

APA, Harvard, Vancouver, ISO, and other styles

33

Santos, Cristina Maria P., Roberto B. Faria, Juan O. Machuca-Herrera, and Sérgio de P. Machado. "Equilibrium geometry, vibrational frequencies, and heat of formation of HOBr, HBrO2, and HBrO3 isomers." Canadian Journal of Chemistry 79, no. 7 (2001): 1135–44. http://dx.doi.org/10.1139/v01-082.

Full text

Abstract:

The equilibrium geometries, vibrational frequencies, heat capacity, and heat of formation for compounds of general formula HBrOx were calculated by DFT (BP and pBP methods) with DN* and DN** numerical basis sets. The comparison of our HOBr calculated results with the HOBr experimental values points out that the BP and pBP methods are as good as other ab initio and DFT methods related in the literature employing extended basis sets. The calculated HBrOx total energy and heat of formation values, at 0 and 298.15 K, present the following order: HOBr < HBrO; HOOBr < HOBrO < HBrO2; HOOOBr

APA, Harvard, Vancouver, ISO, and other styles

34

Böhm, Stanislav, and Otto Exner. "Steric effects of the alkyl groups: evaluation on isolated molecules by means of isodesmic reactions." Org. Biomol. Chem. 5, no. 13 (2007): 2081–86. http://dx.doi.org/10.1039/b704459c.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Friedl, Zden?k, J�n Biro?, and Otto Exner. "A test of electrostatic and reaction-field theories: equilibria in isodesmic reactions of some chlorobenzenes." Journal of the Chemical Society, Perkin Transactions 2, no. 3 (1990): 459. http://dx.doi.org/10.1039/p29900000459.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Böhm, Stanislav, and Otto Exner. "Steric effects of polar substituents evaluated in terms of energy by means of isodesmic reactions." Organic & Biomolecular Chemistry 6, no. 6 (2008): 1092. http://dx.doi.org/10.1039/b717913h.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Waite, Simone L., Amir Karton, Bun Chan, and Alister J. Page. "Thermochemical stabilities of giant fullerenes using density functional tight binding theory and isodesmic‐type reactions." Journal of Computational Chemistry 42, no. 4 (2020): 222–30. http://dx.doi.org/10.1002/jcc.26449.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Gosse, Tammy L., and Raymond A. Poirier. "Exo selectivity and the effect of disubstitution in the DielsAlder reactions of butadiene with 3,3-disubstituted cyclopropenes." Canadian Journal of Chemistry 82, no. 11 (2004): 1589–96. http://dx.doi.org/10.1139/v04-115.

Full text

Abstract:

A density functional computational study was performed to accomplish two tasks: to examine the endoexo selectivity in the DielsAlder reactions of 3,3-disubstituted cyclopropenes with s-cis-butadiene, and to study the effect of disubstitution on the reactivity of the cyclopropene dienophile. Cyclopropene is substituted at C-3 with CH3, SiH3, NH2, PH2, OH, SH, F, and Cl; both 3-substituted and 3,3-disubstituted ground states are examined to determine relative reactivities. The exo transition-state structures are consistently lower in energy than the endo transition-state structures for the 3,3

APA, Harvard, Vancouver, ISO, and other styles

39

Al-Omari, Hamzeh S. M. "Semiempirical Method MNDO for the Evaluation of the Effect of Different Substituents at the Imine-Carbon Position on the Acetaldemine-Vinylamine Tauotomerization and Comparison to the Substitution at α-Position". Zeitschrift für Naturforschung A 59, № 12 (2004): 987–96. http://dx.doi.org/10.1515/zna-2004-1218.

Full text

Abstract:

MNDO calculations have been employed to study the effect of some substituents of the acetaldemine-vinylamine tautomeric system at the imine-carbon position of CH3CXNH, where X = H, F, CN, NH2, NO2, BH2, CH3 and CF3. It is found that the substitutents F, NH2 and NO2 encourage the formation of the enamine tautomer. The substitutents CN, CH3, CF3 and BH2 encourage the formation of the imine tautomer. Isodesmic reactions, free energy change (ΔG), charge distribution and energy gap (Eg) between HOMO and LUMO were used to prove these findings. Resonance stabilization was a major factor in the determ

APA, Harvard, Vancouver, ISO, and other styles

40

Böhm, Stanislav, and Otto Exner. "Estimation of Resonance Energy from Forced Nonplanar Conformations of Conjugated Molecules." Collection of Czechoslovak Chemical Communications 70, no. 10 (2005): 1577–88. http://dx.doi.org/10.1135/cccc20051577.

Full text

Abstract:

Energies of 39 derivatives of buta-1,3-diene in the twisted conformation were calculated within the framework of the density functional theory at the B3LYP/6-311+G(d,p) level. By comparing with the same molecules in their natural minimum-energy conformations, a scale of resonance effects of various substituents was obtained and expressed in terms of isodesmic reactions. Comparison with other similar scales revealed that this model is not particularly advantageous, its main shortcoming being the relatively small effect. In any case it confirmed that the scales of resonance effects obtained from

APA, Harvard, Vancouver, ISO, and other styles

41

Furet, Pascal, George Hallak, Robert L. Matcha, and Richard Fuchs. "Substituent effects on acetylene stability. A comparison of STO-3G, 6-31G, 6-31G**, and 6-311G** calculations." Canadian Journal of Chemistry 63, no. 11 (1985): 2990–94. http://dx.doi.org/10.1139/v85-496.

Full text

Abstract:

Abinitio calculations using STO-3G, 6-31G, 6-31G**, and 6-311G** basis sets and standard geometries, and 6-31G and 6-311G** basis sets with 6-31G optimized geometries have been performed on a series of acetylene derivatives (H—C≡C—R; –R is —CH3, —Li, —C≡N, [Formula: see text] —NH2,—C≡CH, —CH—CH2, and —F). Substituent effects on stability have been studied using isodesmic methyl exchange reactions (H—C≡C—R + CH4 → H—C≡C—H + CH3R). STO-3G and 6-31G calculations have been carried out for methyl exchange reactions involving several large substituents including phenyl, and for the tert-butyl exchan

APA, Harvard, Vancouver, ISO, and other styles

42

Selmi, Massimo, and Jacopo Tomasi. "Ab-initio calculations and semiempirical corrections to obtain enthalpies of formation of hydrocarbons through isodesmic reactions." Journal of Physical Chemistry 99, no. 16 (1995): 5894–98. http://dx.doi.org/10.1021/j100016a025.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Charaya, Sumit, and Joseph W. Bozzelli. "Thermochemistry, Bond Energies and Internal Rotor Potentials of Acetic Acid Hydrazide, Acetamide, N-Methyl Acetamide (NMA) and Radicals." Thermo 1, no. 1 (2021): 15–31. http://dx.doi.org/10.3390/thermo1010002.

Full text

Abstract:

Structures, thermochemical properties, bond energies, and internal rotation potentials of acetic acid hydrazide (CH3CONHNH2), acetamide (CH3CONH2), and N-methyl acetamide (CH3CONHCH3), and their radicals corresponding to the loss of hydrogen atom, have been studied. Gas-phase standard enthalpies of formation and bond energies were calculated using the DFT methods B3LYP/6-31G(d,p), B3LYP/6-31G(2d,2p) and the composite CBS-QB3 methods employing a series of work reactions further to improve the accuracy of the ΔHf°(298 K). Molecular structures, vibration frequencies, and internal rotor potentials

APA, Harvard, Vancouver, ISO, and other styles

44

Liu, Hong Xia, and Hui Liu. "Study of the Thermodynamic Properties for Polychlorinated 5,10-Dihydrophenarsazine." Advanced Materials Research 546-547 (July 2012): 42–47. http://dx.doi.org/10.4028/www.scientific.net/amr.546-547.42.

Full text

Abstract:

136 polychlorinated 5,10-dihydrophenarsazine (PCPhZ) in the ideal gas state at 298.15 K and 101.3 kPa have been calculated at the B3LYP/6-31G* level using Gaussian 03 program, and their thermodynamic parameters were obtained. The isodesmic reactions were designed to calculate standard enthalpy of formation (ΔfHө) and standard free energy of formation (ΔfGө) of PCPhZ congeners. The relations of these thermodynamic parameters with the number and position of Cl atom substitution (NPCS) were discussed, and it was found that there exist high correlation between thermodynamic parameters (heat capaci

APA, Harvard, Vancouver, ISO, and other styles

45

YU, HONG-BO, FENG-CHAO CUI, YONG-XIA WANG, HONG-XIA LIU, and JING-YAO LIU. "DIRECT DENSITY FUNCTIONAL THEORY DYNAMICS STUDY FOR THE CH3OCF2CF2OCH3 + OH REACTION." Journal of Theoretical and Computational Chemistry 10, no. 02 (2011): 231–44. http://dx.doi.org/10.1142/s0219633611006402.

Full text

Abstract:

The mechanism and kinetics of the reaction of CH3OCF2CF2OCH3 with OH radicals have been studied theoretically by a direct density functional theory dynamics method. All possible H -abstraction channels and displacement processes taking place on two different conformers of CH3OCF2CF2OCH3 have been taken into consideration. The potential energy surface information including the optimized geometries and harmonic vibrational frequencies of all the stationary points and barrier heights involved in these channels were obtained at the BB1K/6-31+G(d,p) level of theory. The rate constants were calculat

APA, Harvard, Vancouver, ISO, and other styles

46

Sivaramakrishnan, R., Robert S. Tranter, and K. Brezinsky. "Ring Conserved Isodesmic Reactions: A New Method for Estimating the Heats of Formation of Aromatics and PAHs." Journal of Physical Chemistry A 109, no. 8 (2005): 1621–28. http://dx.doi.org/10.1021/jp045076m.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Lories, Xavier, Jacques Vandooren, and Daniel Peeters. "Heats of formation and hydrogenation of fused bicyclic benzene isomers: The use of Ring Conserving Isodesmic Reactions." Computational and Theoretical Chemistry 966, no. 1-3 (2011): 244–49. http://dx.doi.org/10.1016/j.comptc.2011.03.007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Abronin, I. A., and L. V. Volkova. "On the relationship between the energy characteristics of the isodesmic reactions of polychlorinated dioxins and their toxicity." Russian Chemical Bulletin 68, no. 4 (2019): 867–69. http://dx.doi.org/10.1007/s11172-019-2498-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Ochiai, Masahito, Takuya Sueda, Kazunori Miyamoto, Paul Kiprof та Viktor V. Zhdankin. "trans Influences on Hypervalent Bonding of Arylλ3-Iodanes: Their Stabilities and Isodesmic Reactions of Benziodoxolones and Benziodazolones". Angewandte Chemie 118, № 48 (2006): 8383–86. http://dx.doi.org/10.1002/ange.200603055.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Ochiai, Masahito, Takuya Sueda, Kazunori Miyamoto, Paul Kiprof та Viktor V. Zhdankin. "trans Influences on Hypervalent Bonding of Arylλ3-Iodanes: Their Stabilities and Isodesmic Reactions of Benziodoxolones and Benziodazolones". Angewandte Chemie International Edition 45, № 48 (2006): 8203–6. http://dx.doi.org/10.1002/anie.200603055.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!