NMR Relaxation Time Studies of Ionophoric Calixarene Esters

Abstract
Relaxation times of ethoxycarbonylmethyl derivatives of p-t-butylcalix[n]arenes (n = 4, 6, and 8) were estimated for the first time with 1H NMR. It was shown that the benzene units feature a “seesaw” motion around the ArCH2Ar circle and the motion is suppressed by Na+ serving as a template ion.