Abstract:
Synthetic chemists have developed robust methods to synthesize discrete molecules, linear and branched polymers, and disordered cross-linked networks. However, two-dimensional (2D) polymers prepared from designed monomers have been long missing from these capabilities, both as objects of chemical synthesis and in nature. Recently, new polymerization strategies and characterization methods have enabled the unambiguous realization of 2D, covalently linked macromolecular sheets. In the early realization of this synthetic challenge, polymerization conditions were identified empirically by screening polymerization conditions through powder x-ray diffraction analysis of the insoluble powder products, which provided polycrystalline samples with crystalline domains with average in-plane dimensions of 25-50 nm. More recently, we have developed tools to study these polymerizations experimentally and computationally, which has given rise to the first controlled two-dimensional polymerizations, along with materials of improved quality. I will present these approaches and the properties of high-quality 2D polymers that are now starting to emerge.