Deprotonation of calixarenes in acetonitrile.

作者： Ian D. Cunningham , Marc Woolfall

关键词: Hydrogen bond 、 Selectivity 、 Calixarene 、 Medicinal chemistry 、 Chemistry 、 Molecule 、 Acetonitrile 、 Titration 、 Spectrophotometry 、 Deprotonation 、 Inorganic chemistry

摘要: The pKa values for calixarenes in MeCN have been determined by selective titration with bases using a spectroscopic method. These are as follows: calix[4]arene pKa(1) = 19.06 ± 0.22, pKa(2) > 33; calix[6]arene 15.59 0.06, 23.85 0.35, pKa(3) calix[8]arene 17.20 0.20, 20.32 0.31, 33. trends acidity rationalized structures generated DFT model. For mono-deprotonation, the degree and nature of hydrogen bonding anion is dominant factor; di-deprotonation, spatial separation anionic charges becomes important.