The hydrogen bonding and conformations of p- tert-butylcalix[4]arene as studied by IR spectroscopy and by DFT calculations

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 62; no. 1; pp. 483 - 493
• Main Authors: Furer, V.L., Borisoglebskaya, E.I., Zverev, V.V., Kovalenko, V.I.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.11.2005
• Subjects: Calixarenes; Calixarenes - chemistry; Conformations; Hydrogen Bonding; IR spectra; Models, Molecular; Models, Theoretical; Molecular Conformation; Molecular Structure; Normal vibrations; Spectrophotometry; Spectrophotometry, Infrared; Valine - analogs & derivatives; Valine - chemistry; Vibration; Conformations; IR spectra; Normal vibrations; Calixarenes; Hydrogen bonding
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2005.02.001

IR and far IR spectra of p- tert-butylcalix[4]arene were recorded at various temperatures between 16 and 180 °C and spectra of solutions and crystalline solids were obtained. Ab initio density functional calculations gave vibrational frequencies and infrared intensities for four conformers: cone, partial cone, 1,2- and 1,3-alternate. Complete assignments were made for experimental IR spectra of the cone conformer. The bands characteristic for each conformation were defined. It was revealed that O H stretching low-frequency shift Δ ν in the cone conformation exceeds Δ ν shifts for other conformers. The effect was stipulated by a cooperative interaction of cyclic hydrogen bonds. The obtained spectra-structure correlation can be used for characteristic of calixarenes conformation.