Highly Porous Scandium(III) Tetrafluoroisophthalate\nFramework for Adsorptive Separation of Light Alkanes

The\nseparation of light alkanes is one of the most important tasks\nfor modern industry due to the widespread use of ethane and propane\nas chemical feedstocks. Their extraction from natural gas is a challenging\ntask and is now carried out by cryogenic distillation at a limited\nnumber of plants around the world. The development of new materials\nfor adsorption separation is therefore important. Among the different\ntypes of adsorbents, metal–organic frameworks (MOFs) are one\nof the most interesting due to their infinite design possibilities.\nHere we present a highly porous perfluorinated MOF [Sc(OH)(1,3-tFbdc)]\n(<b>1</b>,1,3-<i>t</i>Fbdc<sup>2–</sup>1,3-C<sub>6</sub>F<sub>4</sub>(COO)<sub>2</sub><sup>2–</sup> tetrafluoroisophthalate\nlinker) with a BET surface area greater than 1000 m·g<sup>–1</sup> and its ability to separate light alkanes was investigated. The\nability of <b>1</b> to separate light hydrocarbons at 0 and\n25 °C is demonstrated by IAST calculation of selectivity factors\nas well as by dynamic breakthrough experiments. The role of fluorine\nsubstituents within the organic linker of MOF <b>1</b> in gas\nadsorption is revealed by quantum chemical calculations.