title: Rapid, Low Temperature Formation of Imine-Linked Covalent Organic Frameworks Catalyzed by Metal Triflates.
abstract: Imine-linked two-dimensional covalent organic frameworks (2D COFs) are crystalline polymer networks with enhanced stability compared to boronate ester-linked systems and with broad monomer scope. They are traditionally prepared by condensing polyfunctional aldehydes and amines at elevated temperature in a mixture of organic solvents and aqueous CH3CO2H, which catalyzes imine formation and exchange. Here we employ metal triflates, which are water-tolerant Lewis acids, to accelerate 2D imine-linked COF synthesis and improve their materials quality. Low catalyst loadings provide crystalline polymer networks in nearly quantitative yields. These conditions are demonstrated for several COFs, including heteroatom-containing systems of interest for optoelectronic applications.
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Michio
authors.identifier: http://orcid.org/0000-0002-6037-0228
authors.initials: M
authors.lastname: Matsumoto
authors.affiliation: School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Raghunath R
authors.identifier: http://orcid.org/0000-0002-3237-7334
authors.initials: RR
authors.lastname: Dasari
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Woojung
authors.identifier: http://orcid.org/0000-0001-5329-0628
authors.initials: W
authors.lastname: Ji
authors.affiliation: School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Cameron H
authors.initials: CH
authors.lastname: Feriante
authors.affiliation: School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Timothy C
authors.identifier: http://orcid.org/0000-0002-0270-0364
authors.initials: TC
authors.lastname: Parker
authors.affiliation: School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Seth R
authors.identifier: http://orcid.org/0000-0001-6921-2536
authors.initials: SR
authors.lastname: Marder
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: William R
authors.identifier: http://orcid.org/0000-0002-3635-6119
authors.initials: WR
authors.lastname: Dichtel