Creating libraries of porous materials derived from γ-zirconium phosphate: Pillaring with polyphenylethynyl diphosphonates

The synthesis of polyphenylethynyl diphosphonic acids was accomplished as well as their incorporation to γ-ZrP by topotactic phosphate/phosphonate partial exchange. The materials, characterized by solid-state NMR, XRD, elemental analysis and molecular modelling, bore truly pillared structures with a high degree of ultramicroporosity. The remaining surface phosphates from the partial phosphate/phosphonate replacement were further exchanged with methylphosphonate, phosphite or hypophosphate leading to a library of new materials that retained the pillared ultramicroporous structure. The porous solids displayed reasonable capacities to store hydrogen by physisorption.

Figure optionsDownload as PowerPoint slideResearch highlights
► Layered ZrP is a versatile inorganic salt.
► Diphosphonates of any structure are readily accessible.
► Their topotactic exchange into γ-ZrP leads to microporous structures.
► Multiple topotactic exchange leads to libraries of materials.
► The properties of these materials like physisorption can be confronted to subtle structure changes.