ELECTRON-SPIN RELAXATION AND ROTATIONAL-DYNAMICS OF TETRAMETHYLETHYLENE RADICAL-CATION IN ZSM5

Electron spin relaxation and methyl rotation dynamics of the tetrameth ylethylene radical cation in ZSM5 were examined to probe the zeolite-g uest and sorbate-sorbate interactions. T1 and T2 relaxation times and the intensity of the E lines due to tunneling rotation of methyl group s were measured as a function of temperature, sorbate loading and co-a dsorbed argon. The EPR results demonstrate that site heterogeneity and sorbate-induced lattice distortions can affect the measured quantitie s. Sorbate-sorbate interactions, when they occur, can also be detected . (C) 1998. Published by Elsevier Science B.V. All rights reserved.