A 'Thermodynamically Stable' 2D Ni-MOF over a Wide pH Range with Scalable Preparation for Efficient C2s over C1 Hydrocarbon Separations.

Design and construction of 'thermodynamically stable' MOFs surviving in liquid water, boiling water, acidic/basic solutions over a wide pH range is highly desirable for many practical applications especially adsorption based gas separations with obvious scalable preparations. Herein, we have designed a new thermodynamically stable Ni-MOF, {[Ni(L)(1,4-NDC)(H 2 O) 2 ]} n , IITKGP-20 displaying moderate porosity with 218 m 2 g -1 BET surface area and micropores along [1 0 -1] direction. As an alternate to cost intensive cryogenic high pressure distillation process for the separation of hydrocarbons, recently MOFs have shown the promise of such separation. Thus, towards application standpoint, this MOF exhibits relatively higher uptake of C 2 s hydrocarbons over the C 1 hydrocarbon at ambient conditions with one of the highest selectivities based on IAST method. Combination of two strategies (presence of stronger metal-N coordination on the spacer and the hydrophobicity on the aromatic moiety of the organic ligand) possibly makes the framework highly robust even stable in boiling water and over a wide range of pH 2-10 and representing the first example of 'thermodynamically stable' MOF displaying 2D structural network. Moreover, this material is easily scalable by refluxing the reaction mixture overnight. Because, such separations are performed in presence of water vapor and acidic gases, there is a great need to explore 'thermodynamically stable' MOFs retaining not only the structural integrity but also the porosity of frameworks.