title: Cyclic cooperative intramolecular hydrogen bond in p-tert-butylcalix[6]arene according to FTIR spectroscopy and DFT studies.
abstract: This article describes a comparative research of IR spectra and H-bonds in the p-tert-butylcalix[6]arene (TB6) and calix[6]arene (C6). IR spectra were computed for compressed cone conformation by DFT method. The assignment of the bands in the IR spectra of the TB6 and C6 was made. The effect of the bulky tert-butyl substituents on the structure and H-bonding in TB6 was established. Our research has shown that in TB6 and C6 the cyclic H-bond is realized, which ensures the existence of a compressed cone conformation. Introduction of tert-butyl substituents in TB6 leads to hardening of H-bonds. Examination of IR spectra showed that when heated TB6 remains in a compressed cone conformation. In a molecule of TB6 and C6 oxygen atoms are in a "boat" conformation.
authors.affiliation: Kazan State Architect and Civil Engineering University, 1 Zelenaya, 420043 Kazan, Russia. Electronic address: furer@kgasu.ru.
authors.forename: V L
authors.initials: VL
authors.lastname: Furer
authors.affiliation: Kazan State Architect and Civil Engineering University, 1 Zelenaya, 420043 Kazan, Russia.
authors.forename: L I
authors.initials: LI
authors.lastname: Potapova
authors.affiliation: A.E. Arbuzov Institute of Organic and Physical Chemistry, RAS, 8 Arbuzov Str., 420088 Kazan, Russia. Electronic address: koval@iopc.ru.
authors.forename: V I
authors.initials: VI
authors.lastname: Kovalenko
keywords: Calixarenes; DFT; Hydrogen bonding; IR spectra; Normal vibrations