Thienothiophene-Based Organic Porous Polymers Combining Different Linkers and Functional Groups: Design, Synthesis, Photophysical, and Charge Transport Properties

Organic covalent frameworks (COFs) are essential for various applications, including solar cells, capacitors, hydrogen production, cancer therapy, bacterial treatment, chemical sensors, and light-emitting diodes. This study presents the design and synthesis of novel conjugated triazine-type porous polymers (P1–P6) and their conjugated monomers (M1--M6), incorporating thienothiophene (TT) rings as π-bridges, along with cyanophenyl, phenyl, and heptyl as different functional groups, and triphenylamine (TPA), tetraphenylethylene (TPE), and carbazole (Cbz) as linkers. The polymers were synthesized via acid-catalyzed trimerization. Photo-injected charge carriers of the polymers and impact of molecular doping on the conductivities with iodine doping were analyzed. The highest photoconductivity, φ∑μ, reached 2.4 × 10⁻⁸ m² V⁻¹ s⁻¹ when doped with I₂ for the heptyl chain-substituted P6 (Cbz-linkage) among the analyzed porous polymers.