Complexation of solvents and conformational equilibria in solutions of the simplest calix[4]arenes

Spectrochim Acta A Mol Biomol Spectrosc. 2015 Jan 5:134:121-6. doi: 10.1016/j.saa.2014.06.048. Epub 2014 Jun 13.

Abstract

Structure optimization and calculation of electronic adsorption spectra of 25,26,27,28-tetrahydroxycalix[4]arene and 25,27-dimethoxy-26,28-dihydroxycalix[4]arene conformers have been performed by density-functional theory using hybrid B3LYP functional in cc-p VTZ and cc-p VDZ basis sets in Gaussian 09 package. Analysis of experimental UV-Vis spectra of solutions of 25,26,27,28-tetrahydroxycalix[4]arene, 4-tert-butylcalix[4]arene and 25,27-dimethoxy-26,28-dihydroxycalix[4]arene in various solvents has been carried out. It was shown that the ratio of absorption maxima at characteristic wavelengths at ca. 274 and 283 nm may be used to assess the extent of calix[4]arene/solvent interactions. The conclusion is drawn that spectral characteristics of calix[4]arenes are strongly affected by acid-base interactions.

Keywords: Calix[4]arene; Conformational analysis; Solvent effects; Supramolecular chemistry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calixarenes / chemistry*
  • Molecular Conformation
  • Molecular Structure
  • Solutions
  • Solvents / chemistry*
  • Spectrophotometry, Ultraviolet

Substances

  • 25,26,27,28-tetrahydroxycalix(4)arene
  • 25,27-dimethoxy-26,28-dihydroxycalix(4)arene
  • Solutions
  • Solvents
  • Calixarenes