Structural characterization of 13C-labeled n-tetracosane adsorbed on the surface of silica gel by high-resolution solid-state 13C NMR spectroscopy

Abstract

13C CP/MAS and PST/MAS spectra of 10% 13C-labeled n-tetracosane adsorbed on the surface of silica gel were measured by means of high-resolution solid-state 13C NMR. From these experimental results, it is found that adsorbed n-tetracosane is in three regions with different molecular motion. In the immobile region, n-tetracosane takes a layer structure with triclinic-like form. In the mobile region, n-tetracosane is undergoing fast transition between trans and gauche conformations and fast rotation along the chain axis.