The Cyclization of Alkyl Side Chains of Naphthalenes: The GC/Potential Energies/FTIR Approach


Gas chromatographic measurements of the retention times of alkyl naphthalenes on packed columns with polar and non-polar stationary phases have proven that the logarithm of the relative retention time increases bi-linearly (not linearly) with the number of carbon atoms in a molecule. This is caused by a strong inclination of alkyl side chains toward intramolecular cyclization. A FTIR spectral analysis has shown that longer alkyl side chains of alkyl naphthalenes are cyclized through an interaction between the terminal CH3 group and the aromatic ring. Conventional aromatic-aliphatic molecules thus become new molecules with quasi-alicyclic rings. This, however, alters the effect of non-covalent van der Waals attractive forces both inside and outside the molecules, which is reflected in an exponential increase of the retention times of alkyl naphthalenes with a side chain longer than propyl and in the bi-linearity of the logarithmic dependence of the relative retention times on the number of carbons in the molecule.

Share and Cite:

Straka, P. , Novotná, M. , Buryan, P. and Bičáková, O. (2014) The Cyclization of Alkyl Side Chains of Naphthalenes: The GC/Potential Energies/FTIR Approach. American Journal of Analytical Chemistry, 5, 957-968. doi: 10.4236/ajac.2014.514103.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Buryan, P. and Macák, J. (1982) Partial Explanation of the Anomaly in the Relationship between the Logarithm of Retention and the Carbon Number of Monohydric Phenols. Journal of Chromatography A, 237, 381-388.
[2] Macák, J., Nabivach, V., Buryan, P. and Sindler, S. (1982) Dependence of Retentions Indices of Alkylbenzenes on Their Molecular Structure. Journal of Chromatography A, 234, 285-302.
[3] Straka, P. and Buryan, P. (2011) A Study of the Behavior of Alkyl Side Chains Phenols and Arenes in Polar and Nonpolar GC Stationary Phases. American Journal of Analytical Chemistry, 2, 324-331.
[4] Risby, T.H., Hsu, T.-B., Sehnert, S.S. and Bhan, P. (1990) Physicochemical Parameters of Individual Hexachlorobiphenyl Congeners. Environmental Science & Technology, 24, 1680-1687.
[5] Janssen, F. (1982) Glass Capillary Gas Chromatography with Liquid Crystals. Chromatographia, 15, 33-37.
[6] García-Raso, A., Ballester, P., Bergueiro, R., Martínez, I., Sanz, J. and Jimeno, M.L. (1987) Estimation of the Polarity of Stationary Phases by Proton Nuclear Magnetic Resonance Spectroscopy Application to Phenyl and Methyl Silicones (OV and SE Series). Journal of Chromatography A, 402, 323-327.
[7] Mathews, J.P. and Chaffee, A.L. (2012) The Molecular Representations of Coal—A Review. Fuel, 96, 1-14.
[8] Howard, A., McIver, J. and Collins, J. (1994) HyperChem Computational Chemistry. Hypercube Inc., Waterloo.
[9] Becker, U. and Allinger, N.L. (1982) Molecular Mechanics. American Chemical Society, Washington DC.
[10] Allinger, N.L. and Yuh, Y.H. (1982) Quantum Chemistry Program Exchange. Indiana University, Bloomington.
[11] Allinger, N.L., Yuh, Y.H. and Lii, J.H. (1989) Molecular Mechanics. The MM3 Force Field for Hydrocarbons. Journal of the American Chemical Society, 111, 8551-8566.

Copyright © 2021 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.