A new anionic metal-organic framework based on tetranuclear zinc clusters: Selective absorption of CO2 and luminescent response to lanthanide (III) ions

A new anionic metal-organic framework, {[H3O](2)[Zn-4(mu(4)-O)(NSBPDC)(4)]center dot 16(H2O)]}(n) (1), was synthesized under solvothermal conditions using a predesigned multifunctional dicarboxylic acid (H2NSBPDC = 6-nitro-2,2'-sulfone-4,4'-dicarboxylic acid). Complex 1 contains 4-connected tetrahedral [Zn-4(mu(4)-O)(CO2)(8)] clusters, which are further linked by the bridging ligands, generating a threefold interpenetrated diamond-like network with ultra-microporous channels. Gas adsorption studies reveal that 1 has good adsorption selectivity for CO2 over CH4 and N-2. In addition, 1 can serve as a host to incorporate lanthanide cations via a targeted ion-exchanged process. Notably, the structure of 1 can be dehydrated and rehydrated reversibly.