New Hyper-Crosslinked Partly Conjugated Networks with Tunable Composition by Spontaneous Polymerization of Ethynylpyridines with Bis(bromomethyl) arenes: Synthesis, Spectral Properties, and Activity in CO2 Capture
Abstrakt
Spontaneous catalyst-free polymerizations of 4-ethynylpyridine (4EPy) and 2-ethynylpyridine with bifunctional quaternizing agents (QAs) of bis(bromomethyl)arenes provide highly crosslinked polymer networks in high yields. 13C cross-polarization magic-angle spinning (CP/MAS) NMR, Fourier transform IR (FTIR) and diffuse reflectance vis spectroscopy confirm that these networks consist of polyacetylene main chains substituted with pyridyl and pyridiniumyl groups, the latter interconnected with -CH 2(arylene)CH2- linkers. Variation of the 4EPy/QA ratio in the polymerization feed results in networks with different extents of crosslinking and pyridyl/pyridiniumyl ratio (N/N+ from 0 to 1.32).
Networks exhibit photoluminescence and are also moderately active in CO 2 capture (the highest uptake is 16.4 cm3 (STP) g -1 at 293 K and an equilibrium CO2 pressure of 750 Torr). Polymerizations of 4-, and 2-ethynylpyridine with bifunctional quaternizing agents of bis(bromomethyl)arenes provide highly crosslinked networks with polyacetylene main chains substituted by pyridyl and pyridiniumyl groups and crosslinked via -CH2(arylene)CH2- linkers.
Depending on the synthesis conditions, the networks differ in crosslinking extent and pyridyl/pyridiniumyl ratio. The networks exhibit photoluminescence and CO 2 capture.