The theoretical study of the heats of formation of organic compounds containing the substituents CH/sub 3/, CF/sub 3/, NH /sub 2/, NF/sub 2/, NO/sub 2/, OH and F
(1988) Journal of Molecular Structure: THEOCHEM — Vol. 41, n° 3-4, p. 249-274 (1988)
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- The heats of formation of some small molecules containing one or more of the following groups -CH/sub 3/, -CF/sub 3/, -NH/sub 2 /, -NHF, NF/sub 2/, -NO/sub 2/, -OH,-F are studied. The calculations have been carried out theoretically, using the isodesmic procedure of W.J. Hehre et al. (1972). In most cases, the thermal corrections were introduced using experimental (when available) or theoretical (at the SCF 6-31G level) vibrational frequencies. It was found that this correction is relatively negligible (compared to the accuracy of the heats of formation determined); nevertheless, the vibrational frequencies remain useful for determining the heat capacity and the entropy. The authors observe that the heats of formation, in families such as XCH/sub 3-n/F/sub n/, XNH/sub 2-n/ and CH/sub 4-n/X/sub n/, are related by quasilinear relations ( Delta H/sub f/ ap /b a/+/b bn/). Finally, the -NF/sub 2 / and -NO/sub 2/ substituents have large and comparable destabilization effects on the heat of formation. All the other substituents are stabilizing; the importance of the stabilization effect depends on the number of fluorine atoms.
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Sana, M., Leroy, G., Peeters, D., & Wilante, C. (1988). The theoretical study of the heats of formation of organic compounds containing the substituents CH/sub 3/, CF/sub 3/, NH /sub 2/, NF/sub 2/, NO/sub 2/, OH and F. Journal of Molecular Structure: THEOCHEM, 41(3-4), 249-274. https://doi.org/10.1016/0166-1280(88)80147-7 (Original work published 1988)