Isolated Hexanuclear Hydroxo Lanthanide Secondary Building Units in a Rare-Earth Polymeric Framework Based on <i>p</i>-Sulfonatocalix[4]arene

RPF9 is a new family of catalytically active metal−organic frameworks (MOFs) prepared with rare-earth elements and p-sulfonatocalix[4]arene, hexanuclear hydroxo lanthanide clusters forming the secondary building units in an open-framework with two-dimensional channels. The synthesis, characterization, and evaluation of sorption properties and catalytic activity of this new rare-earth polymeric framework type are here described.