Superprotonic Conductivity of MOF-808 Achieved by Controlling the Binding Mode of Grafted Sulfamate

Amitosh Sharma; Jaewoong Lim; Seok Jeong; Somi Won; Junmo Seong; Seonghwan Lee; Yung Sam Kim; Seung Bin Baek; Myoung Soo Lah

doi:10.1002/anie.202103191

Superprotonic Conductivity of MOF-808 Achieved by Controlling the Binding Mode of Grafted Sulfamate

Angew Chem Int Ed Engl. 2021 Jun 21;60(26):14334-14338. doi: 10.1002/anie.202103191. Epub 2021 May 6.

Authors

Amitosh Sharma¹, Jaewoong Lim¹, Seok Jeong¹, Somi Won¹, Junmo Seong¹, Seonghwan Lee¹, Yung Sam Kim¹, Seung Bin Baek¹, Myoung Soo Lah¹

Affiliation

¹ Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.

PMID: 33960088
DOI: 10.1002/anie.202103191

Abstract

A metal-organic framework (MOF) having superprotonic conductivity, MOF-808, is prepared by modulating the binding mode of the sulfamate (SA) moieties grafted onto the metal clusters. The activation of the SA-grafted MOF-808 at 150 °C changes the binding mode of the grafted SA from monodentate to bridging bidentate, thus converting the neutral amido (-S-NH₂ ) moiety of the grafted SA to the more acidic cationic sulfiliminium (-S=NH₂⁺ ) moiety. Further, the acidic sulfiliminium moiety of MOF-808-4SA-150 results in more efficient proton conduction than the amido moiety of MOF-808-4SA-60. At 60 °C and 95 % relative humidity, MOF-808-4SA-150 is found to have a proton conductivity of 7.89×10^-2 S cm^-1 , which is more than 30-times higher than that of MOF-808-4SA-60. Moreover, this superprotonic conductivity is well maintained over 1000 cycles of conductivity measurements and for similar cyclic measurements each day for seven days.

Keywords: MOF-808; binding modes; metal-organic frameworks; proton conductivity; sulfamate.

Publication types

Research Support, Non-U.S. Gov't