A novel threefold interpenetrated zirconium metal-organic framework exhibiting separation ability for strong acids.

We report on the synthesis and selective adsorption property of a novel threefold interpenetrated Zr-based metal-organic framework (MOF), [Zr 12 O 8 (OH) 8 (HCOO) 15 (BPT) 3 ] (BPT 3- = [1,1'-biphenyl]-3,4',5-tricarboxylate) (abbreviated as Zr-BPT). This MOF shows a high tolerance to acidic conditions and has permanent pores, the size of which (approx. <5.6 Å) is the smallest ever reported among porous Zr-based MOFs with high acid tolerance. Zr-BPT selectively adsorbs aryl acids due to its strong affinity for them and exhibits separation ability, even between strong acid molecules, such as sulfonic and phosphonic acids. This is the first demonstration of a MOF exhibiting selective adsorption and separation ability for strong acids.