Fig. 1: Schematic illustration of XB-assisted SPP, compounds used in this work, monomer cocrystal and polymer structures, and PXRD patterns before and after polymerization.

a Schematic illustration of XB-assisted SPP of acetylene. b Schematic illustration of polyacetylene synthesis, 2D CMP formation after linker removal, and metal ion adsorption of 2D CMP. The inserted photos show PPDA-CMP-1, 2, and 3 generated from monomer cocrystals 1·6, 1·7, and 1·8, respectively (after linker removal). c Monomers, linkers, and photo-initiator used in this work. d (A) Monomer cocrystal structure of 1·6 determined by single-crystal X-ray diffraction and a possible polymer structure expected from the monomer cocrystal structure. The figure extracts a single x-y plane of the monomer cocrystal and its possible polymer structure, which is a ladder-shaped polymer growing on the x-axis. The ladder-shaped polymer is further connected to the neighboring ladder-shaped polymers on the y-axis, forming a nanosheet in the x-y plane. The discussion of the polymer structure is given in Supplementary Information (Supplementary section 2.2 and Supplementary Fig. 1). B A possible multilayer structure of PPDA-CMP-1, showing that the nanosheets form a layer-by-layer structure on the z-axis. e PXRD patterns of pure XB linker 6 (orange), monomer cocrystal 1·6 (blue), and the polymer obtained from 1·6 via SPP (green), and their calculated PXRD patterns (in gray color and overlapped with the experimental spectra). 60% of the PXRD pattern of the polymer matched that of the monomer cocrystal. f PXRD patterns of pure solid monomer 1 (blue) and the polymer obtained from 1 via solution-phase polymerization (green), and their calculated PXRD patterns (gray). 6% of the PXRD pattern of the polymer matched that of the solid monomer.