Bulk Synthesis of Two-Dimensional Polymers: The Molecular Recognition Approach

Abstract

This manuscript describes the bulk synthesis of shape persistent two-dimensional (2D) polymers using the self-assembly of rigid precursor moelcules into bilayers. A precursor was synthesized with a structure that encodes for the necessary molecular recognition events to form bilayers with internal orientational order. These events include homochiral interactions and confine reactive functions to planes leading to covalent stitching of flat polymers. The resulting molecular objects have a monodisperse thickness of 5 nm and polydisperse planar dimensions on the order of hundreds or thousands of nanometers. One of the stitching reactions, the oligomerization of acrylate groups to form an all-carbon backbone, is catalyzed by the presence of dipolar stereocenters 13 atoms away from the double bond. These enantiomerically enriched stereocenters are substituted by nitrile groups which react to generate the second stitching backbone of the plate-shaped molecules. A computer simulation indicates that 2D polymers of molar mass in the range of millions can be formed with extremely short stitching backbones provided planar confinement of functions is achieved by molecular recognition events. `Bulk` syntheses of shape persistent 2D polymers which do not require external boundaries to confine monomers into 2D spaces may lead to many interesting advanced materials. 35 refs., 17 figs.