A NEW METHOD FOR GENERATING CHROMIUM(III) INTERCALATED CLAYS

A new approach to chromium(III) pillared clays involved intercalation of montmorillonite clay with polynuclear species prepared by the base catalysed polymerization of either [Cr(H2O)(6)](3+) or discrete polynu clear Cr(III) aqua ions. Sharp powder X-ray diffraction patterns with d(001) spacings of 15.5 to 18.0 Angstrom were obtained which increased with aging times and [Cr(III)]. Ion-exchange techniques revealed the presence of large, highly charged interlayer oligomers which became fi rmly bound to the clay structure upon drying. The room temperature air dried materials gave d(001) spacings of up to 18 Angstrom whilst thos e heated to 573 K gave d(001) spacings of about 16 Angstrom.