Synthesis and Characterization of Regioregular Polymers Containing Substituted Thienylene/Bithienylene and Phenylene Repeating Units

Abstract

Regioregular polymers poly(3-alkyl-2,5-thienylene-alt-1,4-phenylene) (PBTCn, n ) 4, 8, 12) and poly [1,4-bis(3-alkyl-2-thienyl)phenylene] (PBTBCn, n ) 4, 8, 12), which contain alternating phenylene and substituted thienylene or bithienylene repeating units, have been chemically and/or electrochemically synthesized and characterized. Their structures are consistent with that expected as indicated by NMR, FTIR, and microanalysis. The change in glass transition temperature and UV-vis and fluorescence spectra with modification of polymer backbone and increase of the alkyl chain length has been observed and discussed. The PBTCn series shows better thermal stability in air, and the compounds in the series are partially crystalline. The PBTCn polymers have liquid crystalline properties as shown by MDSC, XRD, and polarized optical microscopy. XPS study performed on both the neutral and doped states shows the formation of charge carrier in the polymer backbone when doped. The polymers are both p-and n-dopable as indicated by cyclic voltammetry. Electrochromism when the polymers are p-doped is also evidenced by the spectral changes in UV-vis-NIR region.

A novel multichromic copolymer of 1,4-bis(3-hexylthiophen-2-yl)benzene and 3,4-ethylenedioxythiophene prepared via electrocopolymerization

“…In addition, PBHThBe film presents dual-color electrochromism, which exhibits yellow (neutral state) and blue (doped state) during the redox loop. Structurally similar polymers were reported by Reynolds and co-workers [18] and Chan and co-workers [17] to show very similar phenomena. Table 1 reveals the electrochromic switching behavior of PBHThBe film monitored at 396 and 1100 nm in 0.1 M LiClO 4 / ACN solution between 0.60 V and 1.10 V with a residence time of 8 s. The optical contrast (DT%) for PBHThBe at 396 nm and 1100 nm are 24% and 30%, respectively.…”

“…In order to overcome these drawbacks, various thiophene-based oligomers have been invented [15,16]. Recently, Chan and co-workers have reported a serial of oligomers containing alternating phenylene and alkyl-substituted thienylene units whose polymers are regioregular and soluble in organic solvents [17]. Reynolds and co-workers have designed three discrete oligomeric systems and have successfully constructed the first oligomer-based photopatterned EC device [18].…”

Absorption and photoluminescence of a new thienylene–phenylene copolymer

“…Over the past years, great efforts have been made in polymer science for better elucidation and prediction of the structure and properties of synthetic polymers [10][11][12]. In this paper, the first study of the optical properties of thin films of thienylene-dialkoxyphenylene is reported.…”

Solid-state deep blue and UV fluorescent dyes based on para-bis(2-thienyl)phenylene

“…[25,26]. For the synthesis of the tetra-fluorinated "in" alkylated compound (D), magnesium and a catalytic amount of iodine were stirred with anhydrous THF at reflux.…”