MOBILITY AND REACTIONS OF VO2+ ON HYDRATED SMECTITE SURFACES

The electron spin resonance (ESR) spectra of varying quantities of vanadyl ion (VO**2** plus ) adsorbed on hydrated hectorite indicated that hydrolysis of VO**2** plus was promoted at low levels of adsorption. The hydrolyzed product was adsorbed on the clay surfaces, with a ligand environment that was partially aqueous and partially hydroxide in nature. Greater amounts of VO**2** plus adsorbed on wetted hectorite obscured the ESR spectrum of the strongly adsorbed hydrolysis product with a solution like spectrum. An approximately 50% reduction in rotational mobility of VO**2** plus relative to solution was indicated by the linewidth of this spectrum. Loss in mobility occurred with reduction of the interlamellar spacing until, under strongly dehydrating conditions, the VO(H//2O)//5**2** plus ions became aligned with the V equals O bond axis normal to the plane of the clay platelets. Refs.