Why, on interaction of urea-based receptors with fluoride, beautiful colors develop

J Org Chem. 2005 Jul 8;70(14):5717-20. doi: 10.1021/jo050528s.

Abstract

[reaction: see text] Urea-based receptors, containing electron-withdrawing chromogenic substituents, in a DMSO solution, in the presence of varying excess of fluoride, do not form H-bond complexes, but undergo stepwise deprotonation of the two N-H fragments, an event which is signaled by the development of vivid colors. Double deprotonation is also observed in the presence of hydroxide. Less basic anions (CH3COO-, H2PO4-) induce deprotonation of only one N-H.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetates / chemistry
  • Anions
  • Color
  • Dimethyl Sulfoxide / chemistry
  • Drug Interactions
  • Electrons
  • Fluorides / chemistry*
  • Hydrogen Bonding
  • Hydroxides / chemistry
  • Phosphates / chemistry
  • Protons
  • Urea / chemistry*

Substances

  • Acetates
  • Anions
  • Hydroxides
  • Phosphates
  • Protons
  • Urea
  • Fluorides
  • Dimethyl Sulfoxide