The dependence of the line shifts in NMR spectra of adsorbed molecules on surface coverage with complex formation; 13C-NMR study of the interaction of acetone with OH groups of a silica Gel

Abstract

Equations for the dependence of observed line shifts in NMR spectra of adsorbates on surface coverage under conditions of fast exchange between physisorbed and chemisorbed molecules are derived. These equations were used to explain 13C-NMR data for adsorption of acetone on the surface of the silica gel. The real chemical shifts of 13CO in spectra from acetone when coordinated by OH groups, the equilibrium constants for complex formation, and the concentrations of surface hydroxyl groups were determined experimentally.