Synthesis, Properties, and Tunable Supramolecular Architecture of Regioregular Poly(3-alkylthiophene)s with Alternating Alkyl and Semifluoroalkyl Substituents

Abstract

A series of regioregular poly(3-alkylthiophene)s, Rg(Th- m,n/p ) (m = 5, 8, 11; n = 4; p = 4, 8, 12), with alternating alkyl and semifluoroalkyl substituents has been synthesized by the GRIM polymerization method. Compared with their regiorandom analogues, Rn(Th- m,n/p ), the regioregular analogues exhibit a red shift in electronic transitions in both solution and the solid state as well as considerably higher melting and crystallization temperatures. Increasing the length of alkyl side chains decreases the melting and crystallization transitions significantly. X-ray diffraction indicates that Rg(Th- m,n/p ) polymers form highly ordered bilayer lamellar structures based on the assembly of the amphiphilic Janus-type structure. This supramolecular architecture can be tuned readily by varying the lengths of alkyl (p) and alkylene (m) fragments, affording interlayer distances of 40.1 Å for Rg(Th-5,4/4) and 57.8 Å for Rg(Th-11,4/8). Charge mobility was measured in organic field-effect transistors fabricated using Rg(Th-5,4/12) as the semiconductor layer. Hole mobilities of up to 1.45 × 10−2 cm2/(V s) were measured in FET devices after thermal annealing of the organic semiconductor.

Synthesis and Characterizations of Regioregular Poly(3‐alkylthiophene) with Alter1483ting Dodecyl/1H,1H,2H,2H‐Perfluorooctyl Side Chains

“…3-Dodecylthiophene (4) and its boronic acid ester (5) were synthesized as reported previously. [20,21] tallization. This yield is similar with coupling reaction starting with 2-bromo-3-semifluoroalkyl-thiophenes with longer spacers between the fluoroalkyl chains and thiothene, [20] which indicates that the short ethylene spacer does not affect the reactivity of the coupling with 5.…”

“…[ 20] Polymerizations P3DDFT was synthesized from the monomer 7 via the Grignard metathesis (GRIM) reaction with subsequent Nicatalyzed polymerization, which has been used to polymerize a variety of substituted 2, 2 0 -bithiophenes. [5,6,13] It has been reported that bromine-metal exchange exclusively takes place at the 5-position of the bithiophene ring, leading to the formation of regioregular P3HTs, [20] owing to steric and electronic effects.…”

“…[5,6,13] It has been reported that bromine-metal exchange exclusively takes place at the 5-position of the bithiophene ring, leading to the formation of regioregular P3HTs, [20] owing to steric and electronic effects. P3DDFT showed poor solubility in organic solvents at room temperature, but fairly soluble in chlorobenzene at 100 8C or higher.…”

“…The broad peaks at approximately 2.67-2.74 and 3.01-3.09 ppm are assigned to the regiorandom sequences of a-methylenes in the alkyl and semifluoroalkyl chains, respectively. [20] The ratio of the integrated peak intensity indicates that this polymer has a regioregularity higher than 95%. This high regioregularity of P3DDFT indicates that the shorter spacer between the fluoroalkyl chain and thiophene ring did not largely affect the selectivity of the metal exchange reaction in the polymerization.…”

Novel Cross‐Linked Conducting Polythiophene with Yellow‐Green‐Light‐Emitting Properties and Good Thermal Stability

“…4 Also they can be applied as platform for highly sensitive chem-and bio-detection. 5 To improve the optoelectronic properties and to realize the special applications, chemical modifications have been well performed, 6 one of which is the introduction of substituents with functional groups. 7 The design and synthesis of new conjugated polymers with special functional substituents are highly desirable.…”