High-resolution solid-state 13C nuclear magnetic resonance study of the dynamic behaviour of tetramethylammonium ions trapped in zeolites

Abstract

High-resolution solid-state ¹³C n.m.r. spectra have been measured for various zeolites that trap tetramethylammonium ions in their cages. Various modes of pulse sequence were used to demonstrate that the ions move freely in the cage. ¹³C spin–lattice relaxation times have also been measured, and can be related to the size of the cage similarly to the ¹³C chemical shift. The site occupancy of the ions in the zeolite framework has been discussed quantitatively, realting to the templating effect of the organic base during the crystallization of the zeolites.