Towards a tunable pore size utilizing oxidative pillaring of the mica ferrous tainiolite

Based on the synthetic mica ferrous tainiolite, Cs(Fe2+2Li)Si4O10F2, microporous pillared inter-layered clays (PILCs) are obtained by a facile oxidative intercalation of the organic dication Me2DABCO2+ (N,N-dimethyl-1,4-diazabicyclo[2.2.2]octane dication). By applying increasingly severe oxidative environments, the concept of tuning the pore size of the PILCs by oxidatively decreasing the layer charge and consequently the pillar density in the interlayer space was probed. Unfortunately, the pillar density can only be reduced to a certain extent upon oxidation of structural iron. Further oxidation promotes vacancy formation in the octahedral layer instead of de-intercalation of pillar molecules from the interlayer space to ensure charge neutrality during the oxidation process.