Comparison of Gas Sorption Properties of Neutral and Anionic Metal-Organic Frameworks Prepared from the Same Building Blocks but in Different Solvent Systems

Two different 3D porous metal-organic frameworks, [Zn4O(NTN)(2)]10DMA7H(2)O (SNU-150) and [Zn-5(NTN)(4)(DEF)(2)][NH2(C2H5)(2)](2)8DEF6H(2)O (SNU-151), are synthesized from the same metal and organic building blocks but in different solvent systems, specifically, in the absence and the presence of a small amount of acid. SNU-150 is a doubly interpenetrated neutral framework, whereas SNU-151 is a non-interpenetrated anionic framework containing diethylammonium cations in the pores. Comparisons of the N-2, H-2, CO2, and CH4 gas adsorption capacities as well as the CO2 adsorption selectivity over N-2 and CH4 in desolvated SNU-150 (BET: 1852m(2)g(-1)) and SNU-151 (BET: 1563m(2)g(-1)) samples demonstrate that the charged framework is superior to the neutral framework for gas storage and gas separation, despite its smaller surface area and different framework structure.