Tailoring the pore sizes of microporous pillared interlayered clays through layer charge reduction.

A F-rich potassium hectorite, [K(0.48(2))](inter)[Mg(2.54(8))Li(0.43)](oct)[Si(4)](tet)O(10)F(2), with a layer charge of x = 0.48 per formula unit (pfu) was synthesized by high temperature melt synthesis. After Mg-exchange, the layer charge could be reduced significantly post synthesis by annealing (250 °C) as confirmed by alkylammonium exchange and cation exchange capacity. By pillaring this new low charge material with Me(2)DABCO(2+) (N,N-dimethyl-1,1-diazabicyclo [2.2.2]octane dication) and Rh(bpy)(3)(3+) (rhodium-tris-2,2'-bipyridin trication), we observed a remarkable increase in micropore volume and pore diameter by Ar/Ar(l) physisorption measurements. This method allows the tailoring of pore sizes of pillared clays by reducing the layer charge and consequently the pillar density.