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This paper reviews the development of zincate-complex metathesis polymerization (ZCMP) and its application to protection-free direct synthesis of poly(3-(6-hydroxyhexyl)thiophene) as well as block copolythiophene. The modified ZCMP system using Ni(dcpe)Cl₂ as a catalyst accomplished the preparation of well-defined poly(3-hexylthiophene)s (P3HTs) (M_n up to 35 000 g mol⁻¹) with extremely low PDI (1.03∼1.11). In addition, the first example of all-conjugated block copolythiophene, P3HT-b-poly(3-octadecylthiophene), could be synthesized on the basis of the sequential monomer addition approach based on ZCMP.

Designing intrinsically stretchable semiconducting polymers with suitable charge transport and mechanical properties required for stretchable electronic devices remains a challenge. Here, the authors report terpolymer-based semiconductors with intrinsically high stretchability and mobility.

Strategic design and synthesis of semiconducting polymers with intrinsic ductility and/or stretchability are introduced in this review. The best polymer films show high charge mobilities over 1 cm²V⁻¹s⁻¹ even at 100% tensile strain. On the other hand, their mechanical properties remain inadequate, with high elastic moduli over 0.1 GPa. For semiconducting polymers to be promising candidates in applications such as wearable electronics, electronic skins, and bioelectronics, the trade-off relationship between their electronic and mechanical performance must be prevented by further developing and combining versatile and efficient approaches.

Intrinsically stretchable semiconducting polymer materials have been sought for meeting requirements in the development of wearable intelligent electronic devices. In this focus review, our recent progress in main-chain engineering for development of intrinsically stretchable n-type semiconducting materials is described. The topics include four strategies, namely, (i) a conjugation-break spacer approach, (ii) a block copolymer approach, (iii) an all-conjugated statistical terpolymer approach, and (iv) a sequence random copolymer approach, in which specially designed stress-relaxation units or sequences are incorporated along the main chains of naphthalene-diimide-based n-type semiconducting polymers.

A novel block copolymer, poly(3-hexylthiophene)-b-poly(vinyl catechol) (P3HT-b-PVC) was successfully synthesized via a Click reaction between chain-endfunctionalized P3HT with an alkyne group (P3HT-Alkyne) and chain-end-functionalized poly(3,4-di-tert-butyldimethylsilyloxystyrene) with an azide group (PSVC-Azide), followed by deprotection of tert-butyldimethylsilyloxy groups from the PSVC-Azide segment. Tape test results showed that the adhesion property of the P3HT-b-PVC film was considerably better than that of the corresponding P3HT film. Furthermore, despite the presence of an insulating PVC block in P3HT-b-PVC, the P3HT-b-PVC thin film exhibited a hole mobility comparable to that of the corresponding P3HT thin film.

Thermally stable and photosensitive polymers have been widely developed in recent years for their applications in the electronic packaging such as buffer coating, passivation layers, and insulation layers for redistribution in microelectronics due to their excellent thermal and reasonable dielectric properties. This review describes the recent progress of TSPSPs in the last decade and focuses on their design concept. After a brief introduction of the basic patterning procedure, various chemistries on the design of TSPSPs are highlighted along with two major patterning methodologies such as positive- and negative-working polymers. Furthermore, new applications of TSPSPs, such as low dielectric materials, high refractive index lenses, resists for ITO patterning, and π-conjugated polymers for organic-field effect transistors, are also introduced.

In this study, stoichiometry-independent Migita–Kosugi–Stille coupling polycondensation was performed between 2,5-bis(trimethylstannyl)thiophene and an ester-functionalized dibromo monomer, bis(2-butyloctyl) 2,5-dibromoterephthalate, to obtain high-molecular-weight π-conjugated poly(phenylene thienylene) (M_n = 16,800). The method uses a 2-fold excess of the dibromo monomer toward the distannylated monomer. Such successful nonstoichiometric polycondensation may be derived from the intramolecular Pd(0) catalyst transfer on the aromatic dibromo monomer after the first coupling reaction between the dibromo monomer and stannylated compounds during polymerization.

An efficient method to decrease dielectric constant (ɛ) of poly(2,6-dihydroxy-1,5-naphthylene) (PDHN) by introducing bulky alkyl side chains was reported. Poly(2,6-dialkoxy-1,5-naphthylene)s (PDANs) were prepared by the O-alkylation of PDHN with alkyl halides. The ɛ values of PDANs at 10 GHz decreased as the length and size of side chains increased. Especially, PDCHMN exhibited the lowest dielectric constant (ɛ = 2.29). The ε value results were also supported by refractive index measurement.

We have demonstrated that the phase-transfer polycondensation of bisphenol A with 4,4'-dichlorodiphenyl sulfone catalyzed by 18-crown-6 provided poly(arylene ether sulfone)s with high molecular weights even in the non-dehydrated N,N-dimethylacetamide. The obtained poly(arylene ether sulfone)s showed similar or higher number average molecular weights (M_n) compared with that prepared by the conventional polycondensation using azeotropic distillation.

Well-defined aniline-chain-end-functionalized regioregular poly(3–hexylthiophene)s (P3HT-NH₂) have been synthesized on the basis of Grignard metathesis polymerization. The selectivity of monofunctionalization and the high degree of amine functionality (85–92%) were confirmed by MALDI-TOF mass spectroscopy. A block copolymer through ionic interaction was successfully synthesized simply by blending P3HT-NH₂ with carboxy chain-end-functionalized polystyrene. Thermal and optical properties of the block copolymer are investigated by DSC, TGA and UV-vis spectroscopy. The self-assembly behavior of the polymer was observed by AFM showing nanofibril structures with 12–15 nm width.

Herein, we synthesize a new organic-inorganic hybrid material by direct coordination of a chain-end-functionalized naphthalene diimide (NDI)-based n-type semiconducting polymer with thiol group(s), PNDI-SH, to lead sulfide quantum dots (PbS-QDs). The synthesized hybrid n-type material, PNDI-SH:PbS-QD (70:30, w-w), was found to show good dispersibility in organic solvents and excellent atmospheric stability even after storage for 8 months. The formation of PbS-QD nanoclusters is confirmed by transmission electron microscopy (TEM) for a PNDI-SH:PbS-QD (70:30, w-w) thin film, which is also supported by ultraviolet-visible-near-infrared (UV-Vis-NIR) absorption spectroscopy.

We developed the donor–acceptor (D-A) type π-conjugated polymers including the 1,3,4-thiadiazole unit (TDz) with dodecyl side chains for the polymer solar cell application (PSC). The PSC using TDz polymers showed high open-circuit voltage up to 0.965 V based on the deep highest occupied molecular orbital energy levels in the range −5.50 to −5.20 eV. Especially, the D-A polymer with the thienylene vinylene unit yielded the highest J_sc and power conversion efficiency of 0.529% among all the polymers.

This paper reviews the synthetic strategies for HBPs with controlled DB by specially designing monomer architectures. Several research groups including our group have been overcoming the statistical determination of DB in a random polymerization by tuning the rate constant of the first substitution reactions (k₁) and that of the second reaction (k₂) of an AB₂ monomers. As a result, HBPs with 100% DB, linear polymers (0% DB) and HBPs with any percentage of DB have been successfully synthesized.