NMR Relaxation Study of Microdynamics for a CHClF₂ Molecule Adsorbed on a NaY Zeolite

抄録

For H and F nuclei in CHClF₂ adsorbed on a NaY zeolite, dependences of T₁ on temperature, an observation frequency and a pore filling factor are observed. All of these T₁ data are sucessfully analyzed on the basis of both the nucleus–electron dipolar interaction with a Fe³⁺ ion substituting Al³⁺ in the zeolite framework, and the translational diffusion model for adsorbate motion of capture on and release from an adsorption site Na⁺ which compensates charge of Al³⁺ in the aluminosilicate. From these relaxation analyses under the assumption of isotropic random jump of the absorbate molecule, temperature and loading rate dependences of an adsorption lifetime, a mean squared jump distance and a diffusion coefficient are determined. Then, microdynamics of the CHClF₂ molecule are discussed by use of these variables in physical adsorption.