Optimization of direct arylation polymerization (DArP) through the identification and control of defects in polymer structure

Direct arylation of fluoroarenes toward linear, bent-shaped and branched π-conjugated polymers: polycondensation post-polymerization approaches

A direct arylation polycondensation of fluoroarenes with 2,7-dibromo-9,9-dioctylfluorene,F8, was achieved in a low polar solvent, toluene.

Dramatically different charge transport properties of bisthienyl diketopyrrolopyrrole-bithiazole copolymers synthesized via two direct (hetero)arylation polymerization routes

Two diketopyrrolopyrrole-bithiazole copolymers with same building blocks synthesized via direct (hetero)arylation polymerization through different routes show dramatically different charge transport properties.

Impact of structure and homo-coupling of the central donor unit of small molecule organic semiconductors on solar cell performance

Next to the molecular structure, homo-coupling of the central donor moiety has a profound influence on organic solar cell efficiency.

Palladium-catalyzed oxidative direct arylation polymerization (Oxi-DArP) of an ester-functionalized thiophene

A palladium-catalyzed dehydrogenative polycondensation is reported, resulting in high quality polymers from an unsymmetrical ester-containing monomer without preactivation.

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.

High Mobility Ambipolar Diketopyrrolopyrrole-Based Conjugated Polymer Synthesized Via Direct Arylation Polycondensation

A diketopyrrolopyrrole-based conjugated polymer, PDPP-4FTVT, which exhibits ambipolar transport behavior in air with hole and electron mobilities up to 3.40 and 5.86 cm(2) V(-1) s(-1), respectively, is synthesized via direct arylation polycondensation. Incorporation of F-atoms in β-positions of thiophene rings dramatically improves the efficiency of direct arylation polycondensation.

Enabling high-mobility, ambipolar charge-transport in a DPP-benzotriazole copolymer by side-chain engineering

In this article we discuss the synthesis of four new low band-gap co-polymers based on the diketopyrrolopyrrole (DPP) and benzotriazole (BTZ) monomer unit.

In this article we discuss the synthesis of four new low band-gap co-polymers based on the diketopyrrolopyrrole (DPP) and benzotriazole (BTZ) monomer unit. We demonstrate that the BTZ unit allows for additional solubilizing side-chains on the co-monomer and show that the introduction of a linear side-chain on the DPP-unit leads to an increase in thin-film order and charge-carrier mobility if a sufficiently solubilizing, branched, side chain is attached to the BTZ. We compare two different synthetic routes, direct arylation and Suzuki-polycondensation, by a direct comparison of polymers obtained via the two routes and show that direct arylation produces polymers with lower electrical performance which we attribute to a higher density of chain Furthermore we demonstrate that a polymer utilizing this design motif and synthesized via Suzuki-polycondensation ((l-C₁₈)-DPP-(b-C₁₇)-BTZ) exhibits exceptionally high and near balanced average electron and hole mobilities >2 cm² V^–1 s^–1 which are among the highest, robustly extracted mobility values reported for DPP copolymers in a top-gate configuration to date. Our results demonstrate clearly that linear side chain substitution of the DPP unit together with co-monomers that allow for the use of sufficiently long or branched solubilizing side chains can be an attractive design motif for solution processable, high mobility DPP copolymers.

Synthesis of π-Conjugated Polymers Containing Benzodipyrrole Moieties in the Main Chain through Cleavage of C-H Bonds in 1,4-Bis(acetylamino)benzene

Rhodium-catalyzed copolymerization between 1,4-bis(acetylamino)benzene and diynes through C-H bond cleavage afforded π-conjugated polymers containing benzodipyrrole moieties. The polymers with substituted benzene units exhibited nearly the same absorption peaks and HOMO levels. Fluorenone and benzothiadiazole moieties can be also introduced as electron-acceptor units to the main chain by polymerization in tert-amyl alcohol and tetrahydropyran as mixed solvent, leading to absorption at longer wavelength.

Conjugated Polymers à la Carte from Time-Controlled Direct (Hetero)Arylation Polymerization

Direct (hetero)arylation polymerization (DHAP) shows great promise for simple, cheap, and environmentally benign preparation of conjugated polymers, but seems to involve a lack of selectivity when different aromatic C-H bonds are present. We report that some time-controlled DHAP reactions can yield well-defined and processable semiconducting polymers. Following these procedures, various aromatic compounds have been efficiently polymerized, including 2,7-dibromofluorene, 2,7-dibromocarbazole, 1,4-dibromobenzene, bithiophene, dithienyl-benzothiadiazole, and diketopyrrolopyrrole derivatives. All resulting polymers have shown comparable, if not slightly better, properties than their Stille- and Suzuki-synthesized analogs. These findings (re)open the door for the low-cost production of many conjugated polymers for plastic electronics.

The effect of a solvent on direct arylation polycondensation of substituted thiophenes

A suitable solvent for direct arylation polycondensation is related to an electronic nature of thiophene derivatives.

Third-order nonlinear optical properties of 3,4-ethylenedioxythiophene copolymers with chalcogenadiazole acceptors

3,4-Ethylenedioxythiophene–chalcogenadiazole copolymers with a low optical limiting threshold have been synthesized via direct arylation.

Direct arylation polycondensation for efficient synthesis of narrow-bandgap alternating D–A copolymers consisting of naphthalene diimide as an acceptor

Direct arylation polycondensation enables efficient synthesis of narrow-bandgap, well-defined alternating D–A copolymers consisting of naphthalene diimide as the acceptor unit.

Chloride-promoted Pd-catalyzed direct C–H arylation for highly efficient phosphine-free synthesis of π-conjugated polymers

We have successfully demonstrated a chloride-promoted Pd-catalyzed phosphine-free direct C–H arylation for highly efficient synthesis of high molecular weight π-conjugated polymers.

Identifying Homocouplings as Critical Side Reactions in Direct Arylation Polycondensation

Homocouplings are identified as major side reactions in direct arylation polycondensation (DAP) of 4,7-bis(4-hexyl-2-thienyl)-2,1,3-benzothiadiazole (TBT) and 2,7-dibromo-9-(1-octylnonyl)-9H-carbazole (CbzBr₂). Using size exclusion chromatography (SEC) and NMR spectroscopy, we demonstrate that both TBT and Cbz homocouplings occur at a considerable extent. TBT homocoupling preferentially occurs under phosphine-free conditions but can be suppressed in the presence of a phosphine ligand. Cbz homocoupling is temperature-dependent and more prevalent at higher temperatures. By contrast, evidence for chain branching as a result of unselective C-H arylation is not found for this monomer combination. These results emphasize that particular attention has to be paid to homocouplings in direct arylation polycondensations as a major source of main-chain defects, especially under phosphine-free conditions.