An artificial sodium ion channel from calix[4]arene in the 1,3-alternate conformation

The synthesis of a calix[4]arene with pendent polyether substituents is described. The compound was shown by NMR to bind Na+ when in the 1,3-alternate conformation and computational simulations suggest metal binding within the calixarene annulus. 1H NMR indicated that the complexed cation attracts water and the formation of a stable dihydrate was also indicated by in silico methods. Lipid bilayer experiments confirmed that the 1,3-alt calixarene functions as an artificial transmembrane ion in the presence of Na+ but not K+.