A microporous metal–organic framework containing an exceptional four-connecting 4264 topology and a combined effect for highly selective adsorption of CO2 over N2

Abstract

Reported here is a new microporous metal–organic framework, namely [Zn₂(L)(btc)(Hbtc)] [NH₂(CH₃)₂]·(DMF)₂ (H₂O)₄(1), which is synthesized solvo(hydro)thermally by the self-assembly of Zn(NO₃)₂, N⁴,N⁴-di(pyridin-3-yl)-[1,1′-biphenyl]-4,4′-dicarboxamide (L) and 1,3,5-benzenetricarboxylate acid (H₃btc). Its topology can be described as a four-connecting 4²6⁴ matrix containing both tetrahedral metal and ligand nodes. Interestingly, such a matrix has the same topology symbol as that observed in the well known sodalite (SOD) net, but the td10 of 434 is different from the td10 of 791 for the SOD net, indicative of an exceptional four-connecting 4²6⁴ net. Another outstanding point is the highly selective adsorption of CO₂ over N₂, possibly contributed by a combined effect from the charged skeleton, the existence of functional groups of –CONH– and –COOH in 1.