Additive bond-energy scheme with geminal H-H terms Applications to the enthalpies of formation of alkane derivatives

Abstract

The additive bond-energy scheme with geminal H–H terms, previously applied to hydrocarbons and alkyl radicals, has been extended to aliphatic alcohols, ethers, thiols, thioethers, amines, aldehydes and ketones, halogenoalkanes and alkanenitriles. Apart from C–X (X=O, N, S, Cl, Br, I, CN), X–H (X=O, N, S) and C=O terms, it is necessary to introduce an additional C–C term where either carbon atom is attached to an atom of significantly higher electronegativity (O, N, Cl), or to a carbonyl group. It is also necessary to adopt a different geminal H···H term for CH₂X groups. For alkanols, the anomalous methylene increment can be incorporated by postulating a linear dependence of the H···H term in RCH₂OH on the chain length. The agreement between calculated and experimental enthalpies of formation is slightly inferior to that obtained by the Allen method, but requires fewer parameters. A number of experimental enthalpies of formation are identified as being worthy of replication.

References

1. D. W. Smith, J. Chem. Soc., Faraday Trans., 1996, 92, 1141.
2. D. W. Smith, J. Chem. Soc., Faraday Trans., 1996, 92, 4415.
3. H. A. Skinner, J. Chem. Soc., 1962, 4396.
4. H. A. Skinner, in Thermochemistry and its Applications to Chemical and Biochemical Systems, ed. M. A. V. R. da Silva, Reidel, Dordrecht, 1984, p. 589.
5. K. Pihlaja and J. Kankare, Acta Chem. Scand., 1969, 23, 1745.
6. K. Pihlaja, Acta Chem. Scand., 1971, 25, 451.
7. K. Pihlaja, K. Rossi and P. Vainiotalo, J. Chem. Eng. Data, 1985, 30, 387.
8. K. Pihlaja, in Molecular Structure and Energetics, ed. J. F. Liebman and A. Greenberg, VCH, New York, 1987, vol. 2, p. 173.
9. N. Cohen and S. W. Benson, Chem. Rev., 1993, 93, 2419.
10. J. D. Cox and G. Pilcher, Thermochemistry of Organic and Organometallic Compounds, Academic Press, London, 1970, pp. 552–569.
11. J. B. Pedley, Thermochemical Data and Structures of Organic Compounds, TRC, College Station, TX, 1994, vol. 1.
12. M. W. Chase, C. A. Davies, J. R. Downey, D. J. Frurip, R. A. McDonald and A. N. Syverud, J. Phys. Chem. Ref. Data, 1985, 14, suppl. no. 1.
13. D. W. Smith, Aust. J. Chem., 1995, 48, 65.
14. E. L. Eliel, S. H. Wilen and L. N. Mander, Stereochemistry of Organic Compounds, Wiley, New York, 1994, p. 610.
15. G. J. Szasz, J. Chem. Phys., 1955, 23, 2449.
16. J. E. Huheey, Inorganic Chemistry, Harper and Row, New York, 3rd edn., 1983, p. 157.
17. J. P. McCullough and W. D. Good, J. Phys. Chem., 1961, 65, 1430.
18. V. A. Naumov, in Stereochemical Applications of Gas-Phase Electron Diffraction, ed. I. Hargittai and M. Hargittai, VCH, New York, 1988, part B, pp. 93–146.
19. A. J. Kalb, A. L. H. Chung and T. L. Allen, J. Am. Chem. Soc., 1966, 88, 2938.