Balanced Ambipolar Poly(diketopyrrolopyrrole-alt -tetrafluorobenzene) Semiconducting Polymers Synthesized via Direct Arylation Polymerization

“Greener” and modular synthesis of triazine-based conjugated porous polymers via direct arylation polymerization: structure–function relationship and photocatalytic application

Triazine-based conjugated porous polymers were synthesised by direct arylation polymerization and used as photocatalysts for aerobic oxidation of benzylamine.

Direct heteroarylation polymerization: guidelines for defect-free conjugated polymers

Direct (hetero)arylation polymerization (DHAP) has emerged as a valuable and atom-economical alternative to traditional cross-coupling methods for the synthesis of low-cost and efficient conjugated polymers for organic electronics. However, when applied to the synthesis of certain (hetero)arene-based materials, a lack of C-H bond selectivity has been observed. To prevent such undesirable side-reactions, we report the design and synthesis of new, bulky, phosphine-based ligands that significantly enhance selectivity of the DHAP process for both halogenated and non-halogenated electron-rich and electron-deficient thiophene-based comonomers. To better understand the selectivity issues, density functional theory (DFT) calculations have been performed on various halogenated and non-halogenated electron-rich and electron-deficient thiophene-based comonomers. Calculations showed that the presence of bromine atoms decreases the energy of activation (Ea) of the adjacent C-H bonds, allowing undesirable β-defects for some brominated aromatic units. Both calculations and the new ligands should lead to the rational design of monomers and methods for the preparation of defect-free conjugated polymers from DHAP.

Near-Infrared Light-Responsive Semiconductor Polymer Composite Hydrogels: Spatial/Temporal-Controlled Release via a Photothermal "Sponge" Effect

Near-infrared (NIR) light-responsive hydrogels are important for biomedical applications, such as remote-controlled release, but the NIR agents previously used were largely limited to heavy-metal inorganic materials such as gold nanoparticles. In this article, we report a new type of NIR photothermal-responsive hydrogel that can undergo structural changes in response to NIR light for biomedical applications in drug delivery and controlled release. The hydrogels synthesized by integrating a narrow-bandgap semiconductor polymer poly(diketopyrrolopyrrole-alt-3,4-ethylenedioxythiophene) with the polymerization of N-isopropylacrylamide show rapid and reversible mechanical shrinkage upon NIR light irradiation and can serve as carriers for anticancer drug loading and spatial/temporal control of drug release. These stimuli-responsive hydrogels, which can be prepared in different sizes and shapes, integrate photothermal properties and hydrogel characteristics and can provide on-demand, repeated, remote-controlled drug delivery for biomedical applications such as cancer treatment.

To branch or not to branch: C–H selectivity of thiophene-based donor–acceptor–donor monomers in direct arylation polycondensation exemplified by PCDTBT

The possibility for unselective C–H activation of a thiophene-based, donor–acceptor–donor monomer during direct arylation polycondensation is investigated.

C-H Arylation in the Synthesis of π-Conjugated Polymers

C-H activation reactions have allowed us to react traditionally chemically inert bonds in molecules to develop new methods for cross-coupling reactions. This type of reactivity can be applied to conjugated polymer materials in an effort to improve existing synthetic difficulties including harsh reaction conditions, multiple monomer functionalization steps, and organometallic reagent waste. In this Viewpoint, we highlight some of the encouraging advances in direct arylation polymerization (DArP) as well as ongoing challenges for future improvement and utility.

Direct arylation polymerization towards narrow bandgap conjugated microporous polymers with hierarchical porosity

Conjugated microporous polymers are synthesized via facile direct arylation polymerization, resulting in conjugated networks with hierarchical porosity and a narrow bandgap of 1.5 eV.

Narrow bandgap thienothiadiazole-based conjugated porous polymers: from facile direct arylation polymerization to tunable porosities and optoelectronic properties

Conjugated porous polymers with narrow bandgaps, tunable morphologies, porosities and optoelectronic properties are synthesized via facile direct arylation polymerization.