Počet záznamů: 1
The formation of quasi-alicyclic rings in alkyl-aromatic compounds
- 1.0482185 - USMH-B 2019 RIV NL eng J - Článek v odborném periodiku
Straka, Pavel - Buryan, P. - Bičáková, Olga
The formation of quasi-alicyclic rings in alkyl-aromatic compounds.
Journal of Molecular Structure. Roč. 1154, Feb 15 (2018), s. 455-462. ISSN 0022-2860
Institucionální podpora: RVO:67985891
Klíčová slova: alkyl chain * retention times * molecular mechanics * Van der Waals interactions
Kód oboru RIV: CC - Organická chemie
Obor OECD: Organic chemistry
Impakt faktor: 2.120, rok: 2018
The alkyl side chains of n-alkyl phenols, n-alkyl benzenes and n-alkyl naphthalenes are cyclised, as demonstrated by GC measurements, FTIR spectroscopy and molecular mechanics calculations. Cyclisation occurs due to the intramolecular interaction between an aromatic ring (-delta) and a hydrogen of the terminal methyl group (+delta) of an alkyl chain. In fact, conventional molecules are not aliphatic aromatic, but quasi-alicyclic aromatic. With the aromatic molecules formed with a quasi-alicyclic ring, the effect of van der Waals attractive forces increases not only intramolecularly but also intermolecularly. This effect is strong in molecules with propyl and higher alkyl substituents. The increase of intermolecular van der Waals attractive forces results in bi-linearity in the GC retention time of the compounds in question, observed in the dependence of the logarithm of the relative retention time on the number of carbons in a molecule in both polar and nonpolar stationary phases with both capillary and packed columns. The role of van der Waals forces has been demonstrated using the potential energies of covalent and noncovalent interactions for 2-n-alkyl phenols, n-alkyl benzenes and 1-n-alkyl- and 2-n-alkyl naphthalenes.
Trvalý link: http://hdl.handle.net/11104/0277570