Three isostructural anionic frameworks {[(Hdma)(H3O)][In-2(L-1)(2)] center dot 4DMF center dot 5H(2)O}(infinity) (NOTT-206-solv), {[H(2)ppz][In-2(L-2)(2)]center dot 3.5DMF center dot 5H(2)O}(infinity) (NOTT-200-solv), and {[H(2)ppz][In-2(L-3)(2)]center dot 4DMF center dot 5.5H(2)O}(infinity) (NOTT-208-solv) (dma = dimethylamine; ppz = piperazine) each featuring organic countercations that selectively block the channels and act as pore gates have been prepared. The organic cations within the as-synthesized frameworks can be replaced by Li+ ions to yield the corresponding Li+-containing frameworks {Li-1.2(H3O)(0.8)[In-2(L-1)(2)]center dot 14H(2)O}(infinity) (NOTT-207-solv), {Li-1.5(H3O)(0.5)[In-2(L-2)(2)]center dot 11H(2)O}(infinity) (NOTT-201-solv), and {Li-1.4(H3O)(0.6)[In-2(L-3)(2)]center dot 4acetone center dot 11H(2)O}(infinity) (NOTT-209-solv) in which the pores are now unblocked. The desolvated framework materials NOTT-200a, NOTT-206a, and NOTT-208a display nonporous, hysteretic and reversible N2 uptakes, respectively, while NOTT-206a and NOTT-200a provide a strong kinetic trap showing adsorption/desorption hysteresis with H2. Single crystal X-ray analysis confirms that the Li+ ions are either tetrahedrally (in NOTT-201-solv and NOTT-209-solv) or octahedrally (in NOTT-207-solv) coordinated by carboxylate oxygen atoms and/or water molecules. This is supported by Li-7 solid-state NMR spectroscopy. NOTT-209a, compared with NOTT-208a, shows a 31% enhancement in H-2 storage capacity coupled to a 38% increase in the isosteric heat of adsorption to 12 kJ/mol at zero coverage. Thus, by modulating the pore environment via postsynthetic cation exchange, the gas adsorption properties of the resultant MOP can be fine-tuned. This affords a methodology for the development of high capacity storage materials that may operate at more ambient temperatures.