Features that make macromolecules 2D polymers

The article compares two-dimensional (2D) polymers with their congeners, the abundantly available linear polymers (1D) to show that both kinds of macromolecules are in fact polymer molecules. Repeat units and end (or edge) groups fully describe both kinds of structures. Both structures are obtainable as individual entities. Growth mechanisms well known for 1D polymers have now also been either elucidated or postulated for the first few 2D polymers. 2D copolymers are accessible by reacting different monomers in different feed ratios. Molar masses and molar mass distributions are obtainable when analysing 2D polymers in monolayer sheet form. The author therefore concludes that 2D polymers are in fact polymer molecules, very much as their linear 1D counterparts and that both kinds of structures therefore belong in this very subcategory of macromolecules. Dimensionality differences come with significant property differences and may therefore justify dividing the subcategory ‘polymer molecules’ further into 1D, 2D and – in the near future - 3D polymer molecules. In terms of materials, 2D polymers establish a subclass of organic 2D materials with the unique characteristic of meeting the conditions for polymer molecules. [Display omitted] •Molar mass determination by area measurements.•Polymerization mechanism elucidated by single crystal X-ray diffraction.•Linear and 2D polymers meet the same criteria, −except for dimensionality.