Novel thiophene-bearing conjugated microporous polymer honeycomb-like porous spheres with ultrahigh iodine uptake

Abstract

Two conjugated microporous polymers containing thiophene-moieties (SCMPs) were obtained by the polymerization of 3,3',5,5'-tetrabromo-2,2'-bithiophene and ethynylbenzene monomers through the palladium-catalyzed Sonogashira-Hagihara crosscoupling reaction. The resulting SCMPs show high thermal stability with a decomposition temperature above 300 °C. Scanning electron microscopy images show that the resulting SCMPs formed as an aggregation composed of micrometer-sized SCMP spheres, in which honeycomb-like porous spheres with penetrated pores on the surface were observed. Taking advantage of such a unique honeycomb-like porous morphology as well as π-conjugated structures, the SCMPs show ultrahigh absorption performance for iodine vapour with an uptake of up to 345 wt% obtained, which is the highest value reported to date for CMPs, thus making the resulting SCMPs ideal absorbent materials for reversible iodine capture to address environmental issues.

Flexible and UV Resistant Films Based on Thiophene‐Substituted Conjugated Microporous Polymers Bearing Alkyl Chains: Tuning of Rigidity into Soft

“…To ascertain the molecular structures of SCMPs, solid‐state and liquid‐state 13 C NMR spectroscopy ( Figure ) was performed. The principal peaks of the solid‐state 13 C NMR spectrogram are consistent with similar polymer synthesized previously . Carbon atoms in different chemical environments corresponding chemical shift were used to assign the peaks ( Table 1 ).…”

“…The SCMPs were synthesized from acetylenylbenzene and dibromothiophene with palladium catalyzed Sonogashira–Hagihara crosscoupling polycondensation (Scheme ), which was a reliable approach proved by previous work to construct CMPs . The representative molecular structures of SCMPs are shown in Scheme .…”

“…In order to clearly represent the carbon atoms of different chemical environments, the four carbon atoms in the thiophene ring are numbered 7, 8, 9, 18 ( Figure ). The peaks at ≈175 and 142 ppm correspond to two carbon atom connect with the acetylene bond in the thiophene ring (8 and 18) . According to the 13 C solid‐state NMR spectra, the peaks at 55 to 5 ppm are assigned to alkyl group units, and the methyl end groups in the high‐field state, which the peaks of lower chemical shift at ≈14 to 16 ppm ascribed to CH 3 end groups.…”

“…Among these mentioned POPs, CMPs are usually synthesized using metal‐catalyzed crosscoupling chemistry to form 3D networks with extended π‐conjugation. Owing to their finely tuned porosity, larger surface areas, high thermal and chemical stability (thermal decomposition temperature greater than 300 °C under nitrogen atmosphere) originated from rigid π‐conjugated structure, CMPs have gained wide attention due to their various potential applications such as gas storage, hydrogen production, catalysis, supercapacitors, light harvesting, iodine capture, sensors, separation, and so on.…”

Nitrogen-doped porous carbon nanoparticle derived from nitrogen containing conjugated microporous polymer as high performance lithium battery anode

“…These specific structures make CMP possesses high chemical, thermal stability and desirable porous structure. Therefore, CMP is widely applied in various domains such as electrodes [7,25,26], catalysis [27], carbon dioxide capture [28] and volatile iodine capture [29,30], etc. More interesting, CMP is the ideal precursor to construct porous carbon because of their tuned porous structure and π-conjugated skeletons.…”