Endo-complexation of alkylammonium ions by calix[4]arene cavity: facilitating cation-π interactions through the weakly coordinating anion approach

J Org Chem. 2014 Oct 17;79(20):9842-6. doi: 10.1021/jo5016689. Epub 2014 Sep 26.


Notwithstanding its small dimensions, the narrow cavity of p-tert-butylcalix[4]arene macrocycle is still able to host alkylammonium guests in the presence of the tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (TFPB(-)) weakly coordinating (or "superweak") anion. As an artificial analogue of biological receptors, cone-shaped calix[4]arene 1d is able to recognize a n-BuNH3(+) guest mainly through a 4-fold cation-π interaction aided by a weak H-bonding interaction. This recognition motif can be used to assembly a 2:1 capsular architecture with a linear diammonium axle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anions / chemistry*
  • Borates / chemistry*
  • Calixarenes / chemistry*
  • Hydrocarbons, Fluorinated / chemistry*
  • Hydrogen Bonding
  • Molecular Structure
  • Phenols / chemistry*
  • Tetraethylammonium / chemistry*


  • Anions
  • Borates
  • Hydrocarbons, Fluorinated
  • Phenols
  • calix(4)arene
  • tetrakis(3,5-bis(trifluoromethyl)phenyl)borate
  • Calixarenes
  • Tetraethylammonium