A nanoporous two-dimensional polymer by single-crystal-to-single-crystal photopolymerization.
Nat Chem
; 6(9): 774-8, 2014 Sep.
Article
em En
| MEDLINE
| ID: mdl-25143211
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 (~1â nm) material that combines precisely defined monodisperse pores of ~9â Å with a high pore density of 3.3 × 10(13) poresâ 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.
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MEDLINE
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Ano de publicação:
2014
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Article