Synthesis of side-chain regioregular and main-chain alternating poly(bichalcogenophene)s and an ABC-type periodic poly(terchalcogenophene)

Abstract

Three unsymmetrical diiodobichalcogenophenes SSeI2, STeI2, and SeTeI2 and a diiodoterchalcogenophene SSeTeI2 were prepared to synthesize a new class of polychalcogenophenes with precisely controlled sequences by catalyst-transfer polycondensation.

Group 16 conjugated polymers based on furan, thiophene, selenophene, and tellurophene

“…Such trimers can be prepared by starting with previously prepared dimers and reacting them with a stannylated third heterocycle. 57,144,145 While furan-containing alternating copolymers had slightly lower MWs and yields than expected, it is significant that all the alternating copolymers polymerized with Kumada CTP in this manner had generally predictable MWs and low Đ , indicating good catalyst-furan ring affinity and that catalyst ring-walking still occurs over monomeric trimers and over three different heterocycles. 38,144…”

“…72 Heavier polychalcogenophenes in general are more red-shifted due to their stabilization of lower lying LUMO levels, alongside more quinoidal character, higher coplanarity, and greater π-electron delocalization. 145,159,161,162…”

Temperature triggered alternating copolymerization of epoxides and lactones via pre-sequenced spiroorthoester intermediates

“…The strategy to control the alternating sequence without using comonomer pairs is the polymerization of pre-sequenced monomers, however, the synthesis of such monomers can require multiple steps, and may suffer from low yields and limited functional group tolerance in the resulting polymers. 13 Namely, a wide range of spiroorthoesters (SOEs), a class of pre-sequenced monomer, can be synthesized through the coupling of epoxides and lactones ( Scheme 1A ). 14 However, Lewis-acid-catalyzed formation and polymerization 15 of spiroorthoesters to date have suffered from poor selectivity, resulting in the need for distillation, low monomer yields (<50%), low molecular weights, and high dispersities for the resulting polymers.…”

Precision Synthesis of Various Low‐Bandgap Donor–Acceptor Alternating Conjugated Polymers via Living Suzuki–Miyaura Catalyst‐Transfer Polymerization

“…Pioneered by Yokozawa's group, catalyst-transfer polymerization (CTP), where the propagating catalysts do not dissociate from the growing polymers, has been a representative method for the chain-growth polymerization of (hetero)arene monomers. [20][21][22][23] Thus far, CTP based on Kumada (KCTP), [20][21][22][23][24][25][26][27][28][29] Suzuki-Miyaura (SCTP), [30][31][32][33][34][35][36] and Stille cross-couplings [37] have been extensively investigated for the polymerization of simple (hetero)arenes (e.g., thiophene, phenylene, fluorene, and benzotriazole), as well as DD biaryl monomers (e.g., thiophene-phenylene, [38] bichalcogenophene, [39,40] and cyclopentadithiophenephenylene [41] ). However, only a few reports with limited scope have demonstrated the controlled synthesis of DA ACPs because of challenges in efficient ring-walking between D and A.…”