Putting aromatic compounds to work: Rational synthesis of organic 2D polymers

Abstract

This contribution describes two different approaches aimed at the synthesis of monolayer molecular sheets with internal order, or, in other words, 2D polymers. First, an interfacial strategy is presented in which terpyridene-based hexafunctional monomers spread at the air/water interface are connected to one another with the help of metal salts. While this approach leads to micrometer-sized monolayer sheets that are mechanically stable enough to be spanned over several micrometer-sized holes, their internal structure could not yet be proven. The second approach rests upon solid-state photochemistry, and properly designed monomers are covalently connected with one another while being held in layered geometries owing to crystal packing. Exfoliation to single sheets can be achieved, and molecular structure is supported by a Raman spectroscopic analysis. We consider this the first case of a rational synthesis of 2D polymers and briefly touch on the impact this may have.

Room Temperature Synthesis of a Covalent Monolayer Sheet at Air/Water Interface Using a Shape-Persistent Photoreactive Amphiphilic Monomer

“…Because these two 2DP cases rest upon the single crystal approach, structure elucidation was comparably easy. We also reported a variety of covalent and metal–organic monolayer sheets at the air/water interface. − Determining the internal structure of those sheets is a more challenging matter because, in contrast to the single crystal approach, the structure of the monomer assembly at the interface, and thus the starting situation, is not normally known. The covalent monolayer sheet reported here was obtained from the amphiphilic monomer 2 .…”

Strategies in Organic Synthesis for Condensed Arenes, Coronene, and Graphene

“…The perfect graphene sheet extends indefinitely, representing an ideal 2D polymer [103][104][105]. Most examples shown so far described the synthesis of distinct molecular PAHs.…”

Isomeric Routes to Schiff‐Base Single‐layered Covalent Organic Frameworks

“…Two‐dimensional structure‐robust porous nanostructures with covalent linkages, what we called single‐layered covalent organic frameworks (sCOFs), have recently attracted enormous interest due to their higher chemical stability and wide range of potential applications, such as nanofiltration, molecular electronics sensors and so on . The bottom‐up strategy proves to be an effective synthetic strategy to construct sCOFs . Recently, the strategies of thermodynamic equilibrium control, kinetic growth process control, and surface‐catalyzed polymerization have been developed to construct large‐scale high‐quality sCOFs .…”