2D conjugated microporous polyacetylenes synthesized via halogen-bond-assisted radical solid-phase polymerization for high-performance metal-ion absorbents.

The paper reports the first free-radical solid-phase polymerization (SPP) of acetylenes. Acetylene monomers were co-crystalized using halogen bonding, and the obtained cocrystals were polymerized. Notably, because of the alignment of acetylene monomers in the cocrystals, the adjacent C≡C groups were close enough to undergo radical polymerization effectively, enabling the radically low-reactive acetylene monomers to generate high-molecular-weight polyacetylenes that are unattainable in solution-phase radical polymerizations.

Solid-Phase Radical Polymerization of Halogen-Bond-Based Crystals and Applications to Pre-Shaped Polymer Materials.

Liquid vinyl monomers were converted into solid crystals via halogen bonding. They underwent solid-phase radical polymerizations through heating at 40 °C or ultraviolet photo-irradiation (365 nm). The X-ray crystallography analysis showed the high degree of monomer alignment in the crystals.