title: Ionic Covalent Organic Frameworks with Spiroborate Linkage.
abstract: A novel type of ionic covalent organic framework (ICOF), which contains sp(3)  hybridized boron anionic centers and tunable countercations, was constructed by formation of spiroborate linkages. These ICOFs exhibit high BET surface areas up to 1259 m(2)  g(-1) and adsorb a significant amount of H2 (up to 3.11 wt %, 77 K, 1 bar) and CH4 (up to 4.62 wt %, 273 K, 1 bar). Importantly, the materials show good thermal stabilities and excellent resistance to hydrolysis, remaining nearly intact when immersed in water or basic solution for two days. The presence of permanently immobilized ion centers in ICOFs enables the transportation of lithium ions with room-temperature lithium-ion conductivity of 3.05×10(-5)  S cm(-1) and an average Li(+) transference number value of 0.80±0.02. Our approach thus provides a convenient route to highly stable COFs with ionic linkages, which can potentially serve as absorbents for alternative energy sources such as H2, CH4, and also as solid lithium electrolytes/separators for the next-generation lithium batteries.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
authors.forename: Ya
authors.initials: Y
authors.lastname: Du
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
authors.forename: Haishen
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309, USA.
authors.forename: Justin Michael
authors.initials: JM
authors.lastname: Whiteley
authors.affiliation: Storagenergy Technologies, Inc., Salt Lake City, UT, 84120, USA.
authors.forename: Shun
authors.initials: S
authors.lastname: Wan
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309, USA.
authors.forename: Se-Hee
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA. wei.zhang@colorado.edu.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
keywords: covalent organic frameworks; gas adsorption; ionic polymers; lithium-ion conductivity; spiroborates