title: A two-dimensional polymer prepared by organic synthesis.
abstract: Synthetic polymers are widely used materials, as attested by a production of more than 200 millions of tons per year, and are typically composed of linear repeat units. They may also be branched or irregularly crosslinked. Here, we introduce a two-dimensional polymer with internal periodicity composed of areal repeat units. This is an extension of Staudinger's polymerization concept (to form macromolecules by covalently linking repeat units together), but in two dimensions. A well-known example of such a two-dimensional polymer is graphene, but its thermolytic synthesis precludes molecular design on demand. Here, we have rationally synthesized an ordered, non-equilibrium two-dimensional polymer far beyond molecular dimensions. The procedure includes the crystallization of a specifically designed photoreactive monomer into a layered structure, a photo-polymerization step within the crystal and a solvent-induced delamination step that isolates individual two-dimensional polymers as free-standing, monolayered molecular sheets.
authors.affiliation: Laboratory of Polymer Chemistry, Institute of Polymers, Department of Materials, ETH Zurich, Wolfgang-Pauli-Strasse 10, CH-8093                 Zurich, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kissel
authors.forename: Rolf
authors.initials: R
authors.lastname: Erni
authors.forename: W Bernd
authors.initials: WB
authors.lastname: Schweizer
authors.forename: Marta D
authors.initials: MD
authors.lastname: Rossell
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: King
authors.forename: Thomas
authors.initials: T
authors.lastname: Bauer
authors.forename: Stephan
authors.initials: S
authors.lastname: Götzinger
authors.forename: A Dieter
authors.initials: AD
authors.lastname: Schlüter
authors.forename: Junji
authors.initials: J
authors.lastname: Sakamoto
mesh_terms: D000873:Anthracenes / Q000737:chemistry; D003460:Crystallization; D018625:Microscopy, Atomic Force; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D012997:Solvents / Q000737:chemistry
chemical_list: D000873:Anthracenes; D011108:Polymers; D012997:Solvents