title: A nanoporous two-dimensional polymer by single-crystal-to-single-crystal photopolymerization.
abstract: In contrast to the wide number and variety of available synthetic routes to conventional linear polymers, the synthesis of two-dimensional polymers and unambiguous proof of their structure remains a challenge. Two-dimensional polymers-single-layered polymers that form a tiling network in exactly two dimensions-have potential for use in nanoporous membranes and other applications. Here, we report the preparation of a fluorinated hydrocarbon two-dimensional polymer that can be exfoliated into single sheets, and its characterization by high-resolution single-crystal X-ray diffraction analysis. The procedure involves three steps: preorganization in a lamellar crystal of a rigid monomer bearing three photoreactive arms, photopolymerization of the crystalline monomers by [4 + 4] cycloaddition, and isolation of individual two-dimensional polymer sheets. This polymer is a molecularly thin (~1 nm) material that combines precisely defined monodisperse pores of ~9 Å with a high pore density of 3.3 × 10(13) pores cm(-2). Atomic-resolution single-crystal X-ray structures of the monomer, an intermediate dimer and the final crystalline two-dimensional polymer were obtained and prove the single-crystal-to-single-crystal nature and molecular precision of the two-dimensional photopolymerization.
authors.affiliation: Department of Chemistry, University of Nevada, Reno, Nevada, 89557-0216, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kissel
authors.affiliation: Department of Chemistry, University of Nevada, Reno, Nevada, 89557-0216, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Murray
authors.affiliation: Department of Chemistry, University of Nevada, Reno, Nevada, 89557-0216, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Wulftange
authors.affiliation: Department of Chemistry, University of Nevada, Reno, Nevada, 89557-0216, USA.
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Catalano
authors.affiliation: Department of Chemistry, University of Nevada, Reno, Nevada, 89557-0216, USA.
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: King