Achieving Amphibious Superprotonic Conductivity in a CuI Metal-Organic Framework by Strategic Pyrazinium Salt Impregnation

Sajal Khatua; Arun Kumar Bar; Javeed Ahmad Sheikh; Abraham Clearfield; Sanjit Konar

doi:10.1002/chem.201704088

Achieving Amphibious Superprotonic Conductivity in a Cu^I Metal-Organic Framework by Strategic Pyrazinium Salt Impregnation

Chemistry. 2018 Jan 19;24(4):872-880. doi: 10.1002/chem.201704088. Epub 2017 Dec 13.

Authors

Sajal Khatua¹, Arun Kumar Bar¹, Javeed Ahmad Sheikh^{1

2}, Abraham Clearfield², Sanjit Konar¹

Affiliations

¹ Department of Chemistry, IISER Bhopal, Bhopal By-Pass Road, Bhopal, 462066, Madhya Pradesh, India.
² Department of Chemistry, Texas A&M University, College Station, TX, 77843-3255, USA.

PMID: 29064595
DOI: 10.1002/chem.201704088

Abstract

Treatment of a pyrazine (pz)-impregnated Cu^I metal-organic framework (MOF) ([1⊃pz]) with HCl vapor renders an interstitial pyrazinium chloride salt-hybridized MOF ([1⊃pz⋅6 HCl]) that exhibits proton conductivity over 10^-2 S cm^-1 both in anhydrous and under humid conditions. Framework [1⊃pz⋅6 HCl] features the highest anhydrous proton conductivity among the lesser-known examples of MOF-based materials exhibiting proton conductivity under both anhydrous and humid conditions. Moreover, [1⊃pz] and corresponding pyrazinium sulfate- and pyrazinium phosphate-hybridized MOFs also exhibit superprotonic conductivity over 10^-2 S cm^-1 under humid conditions. The impregnated pyrazinium ions play a crucial role in protonic conductivity, which occurs through a Grotthuss mechanism.

Keywords: fuel cells; interpenetrated hosts; porous metal-organic frameworks; proton carrier guests; superprotonic conductivity.