Investigation of hydrogen bonding in p-sulfonatocalix[4]arene and its thermal stability by vibrational spectroscopy

• Published in: Journal of molecular structure 2019-11, Vol.1195, p.403-410
• Main Authors: Furer, V.L., Vandyukov, A.E., Khamatgalimov, A.R., Kleshnina, S.R., Solovieva, S.E., Antipin, I.S., Kovalenko, V.I.
• Format: Article
• Language: English
• Subjects: Calixarenes; DFT; Hydrogen bonding; IR spectra; Raman spectra
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2019.06.008

The vibrational spectra of p-sulfonatocalix [4] arene were studied. The geometrical parameters, the energies, the frequencies and the intensities of the bands in the IR and Raman spectra are calculated for four conformations. The most stable conformation of the p-sulfonatocalix[4]arene is the cone due to the cooperative cyclic intramolecular hydrogen bonding system. The strength of the hydrogen bonds depends on the type of substituent on the upper rim of the calixarene molecules. We studied the process of destruction of calixarenes using IR spectroscopy and TGA methods. Characteristic bands for each conformation were selected. HOMO covers aromatic units with notable conjugation, and LUMO belongs to sulfonate groups. TGA heating curves of samples of p-sulfonatocalix [4]arene (SC4) and p-tertbutylcalix [4]arene (TB4) molecules from room temperature to 600 °C. The inset images show the three IR spectra of the gas phase released during a) 220 °C, (b) 290 °C, (c) 400 °C. [Display omitted] •The FTIR and FT-Raman spectra of p-sulfonatocalix [4]arene were studied.•Normal mode analysis were performed for p-sulfonatocalix [4]arene.•The IR and Raman spectra of p-sulfonatocalix [4]arene were calculated and interpreted.