Hard-templating of Prussian blue analogues in mesoporous silica and organosilica

Prussian blue analogues (PBAs) have been constructed in chiral nematic mesoporous organosilica and silica templates. By functionalizing the surface of the mesoporous hosts with bipyridinium ligands, it was possible to construct PBAs in their interiors through hard templating. The optical properties of the composites were studied and the relationship between the circular dichroism (CD) signals and the UV-Vis absorption spectra was found through mathematical modeling. Efforts to remove the hard templates to give free-standing PBA films with high surface area and pore volume were met with limited success, but it was possible in the case of zinc/iron PBAs to obtain a highly porous PBA sponge that retained the overall morphology of the template. This work demonstrates the potential for hard templating of coordination polymers in mesoporous materials.