Conformations of 1-heptene secondary ozonide as studied by low temperature FT-IR spectroscopy

Autor:	Justinas Ceponkus, Valdas Sablinskas, Ruta Bariseviciute, L. Kimtys
Rok vydání:	2007
Předmět:	Absorption spectroscopy Chemistry Organic Chemistry Matrix isolation Ring (chemistry) Photochemistry Heptene Spectral line Analytical Chemistry Inorganic Chemistry Crystallography chemistry.chemical_compound Ft ir spectroscopy Ozonide Conformational isomerism Spectroscopy
Zdroj:	Journal of Molecular Structure. :186-192
ISSN:	0022-2860
Popis:	Conformational diversity of the 1-heptene secondary ozonides (SOZ) in solid neat films as well as isolated in Ar or CO2 matrices was studied by the means of FT-IR absorption spectroscopy. The ozonization reaction was performed at 77 K in the neat films of the reactants. The spectra of the ozonide were analyzed by combining the experimental data with the results of theoretical calculations performed at B3LYP 6-311++G (3df, 3pd) level. It was found that the samples of 1-heptene secondary ozonide exist as a mixture of three dominating conformers. The most stable conformer is the one with O–O half-chair configuration of the five membered ring, the aliphatic radical attached to the ring in equatorial position and the aliphatic chain being in gauche (∠OCCC ≈ −60°) position. The other two stable conformers are equatorial with aliphatic chain in anti (∠OCCC ≈ 180°) and gauche (∠OCCC ≈ 60°) positions. It was found from Van’t Hoff plots that ΔH of the equatorial anti conformer is equal to 0.24 ± 0.03 kJ/mol. The experimental value of ΔH is in reasonable accordance to the calculated one – 0.5 kJ/mol.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::1a18c05e220f9313c9798b0dfdcd3294 https://doi.org/10.1016/j.molstruc.2007.04.041 Zobrazit plný text záznamu Full Text from ScienceDirect