Surface and intercalate chemistry of layered silicates. Part III. X-Ray investigation of tetrahydropyran and 1,4-dioxan intercalates of montmorillonite

Abstract

Electron-density maps of intercalates of sodium- and strontium-exchanged montmorillonites show that both the interlamellar tetrahydropyran, (I), and 1,4-dioxan molecules, (II), are oriented essentially perpendicular to the aluminosilicate layers. The number of organic molecules per formula unit of silicate [idealised Al₄Si₈O₂₀(OH)₄] lies between 1·0 and 1·3. It is also demonstrated that changes in basal spacings, used alone, yield misleading information concerning the orientation taken up by the organic guest species.