Superacidity in sulfated metal-organic framework-808

Juncong Jiang; Felipe Gándara; Yue-Biao Zhang; Kyungsu Na; Omar M Yaghi; Walter G Klemperer

doi:10.1021/ja507119n

Superacidity in sulfated metal-organic framework-808

J Am Chem Soc. 2014 Sep 17;136(37):12844-7. doi: 10.1021/ja507119n. Epub 2014 Sep 5.

Authors

Juncong Jiang¹, Felipe Gándara, Yue-Biao Zhang, Kyungsu Na, Omar M Yaghi, Walter G Klemperer

Affiliation

¹ Department of Chemistry, University of California, Berkeley and Kavli Energy NanoSciences Institute at Berkeley , Berkeley, California 94720, United States.

PMID: 25157587
DOI: 10.1021/ja507119n

Abstract

Superacids, defined as acids with a Hammett acidity function H0 ≤ -12, are useful materials, but a need exists for new, designable solid state systems. Here, we report superacidity in a sulfated metal-organic framework (MOF) obtained by treating the microcrystalline form of MOF-808 [MOF-808-P: Zr6O5(OH)3(BTC)2(HCOO)5(H2O)2, BTC = 1,3,5-benzenetricarboxylate] with aqueous sulfuric acid to generate its sulfated analogue, MOF-808-2.5SO4 [Zr6O5(OH)3(BTC)2(SO4)2.5(H2O)2.5]. This material has a Hammett acidity function H0 ≤ -14.5 and is thus identified as a superacid, providing the first evidence for superacidity in MOFs. The superacidity is attributed to the presence of zirconium-bound sulfate groups structurally characterized using single-crystal X-ray diffraction analysis.