Toward n-type analogues to poly(3-alkylthiophene)s: influence of side-chain variation on bulk-morphology and electron transport characteristics of head-to-tail regioregular poly(4-alkylthiazole)s

Abstract

Annealed films of regioregular polythiazoles with tri(n-hexyl)silyloxymethyl-side-chains self-organize into crystalline lamellar domains, and show greatly enhanced electron mobility.

Diversifying Cross‐Coupling Strategies, Catalysts and Monomers for the Controlled Synthesis of Conjugated Polymers

“…Both dppp and dppe based catalysts have been used to polymerize a broad range of monomers (Figures and 4). These include phenylenes, thiophenes, pyrroles, furans, selenophenes, tellurophenes, thiazoles, pyridines, fluorenes, thienopyrazines, dithienosiloles, carbazole and rylene diimides . In each of these cases, dramatic differences arise when exploring these different conjugated building blocks.…”

“…Pammer and McNeil have both explored 4‐substituted thiazoles, a related but more electron deficient five‐membered aromatic . Both research teams have noted dramatic changes in solubility for this monomer with the nitrogen atom in the 5‐membered ring, and a large siloxy side chain was necessary to achieve well‐defined polymers with narrow molecular weight distributions.…”

“…Pammer and McNeil have both explored 4-substituted thiazoles, ar elated but more electron deficientf ive-membered aromatic. [53][54][55][56] Both research teams have noted dramatic changes in solubility for this monomer with the nitrogen atom in the 5membered ring, and al arge siloxy side chain was necessary to achieve well-definedp olymers with narrow molecular weight distributions. These studies have illustrated that side chain engineering, alongw ith binding of the metal catalystt ot he psystem,a re important parameters for designing successful chain-growth polymerizations.…”

“…The halogen (X group) most often employed for monomers is bromine because Ar−Br bonds provide an excellent balance between monomer stability and reactivity in oxidative addition (relative bond strengths: Ar−I<Ar−Br<Ar−Cl). Aryl chlorides have been used in a few select cases with nickel catalysts, and aryl iodides have been employed with several palladium‐based catalysts . Many of the monomers used in CTP have two different halogen substituents; this enables selective activation of one position on the arene to form a single regioisomer (X‐Ar‐Y) for subsequent polymerization.…”

Polymer semiconductors incorporating head-to-head linked 4-alkoxy-5-(3-alkylthiophen-2-yl)thiazole

“…As a less electron-rich arene (versus thiophene), thiazole is a commonly used heterocycle along with many of its derivatives that can effectively lower the FMOs of organic semiconductors. [36][37][38][39][40] Other possible benets are the formation of additional intramolecular noncovalent interactions promoted by the N atom of thiazole with other heteroatoms on the adjacent units, 36,41 steric hindrance reduction by elimination of the C-H moiety, 42 and increased intermolecular coulombic interaction contributed by the large polarity of the thiazole core. 36 It was found that the two distinct alkyl chains can well balance the solubility and crystallinity of the previously reported TRTORbased polymers, yielding highly promising device performance in both OTFTs and PSCs.…”