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Abstract: 4,7-Bis(2,3-dihydrothieno [3,4-b] [1,4] dioxin-5-yl)-2-dodecyl-2H-benzo [1,2,3] triazole (BEBT) was polymerized both electrochemically (ePBEBT) and chemically (cPBEBT). Since chemical polymerization enabled a soluble polymer in common organic solvents, a single layer electrochromic device of ePBEBT was constructed. The polymer cPBEBT was also used in bulk heterojunction (BHJ) solar cells as the active layer in combination with a soluble fullerene derivative, 1-(3-methoxycarbonyl)-propyl-1-1-phenyl-(6,6)C61 PCBM. [Copyright &y& Elsevier]

Abstract: Electrochemical copolymerization was utilized to combine several properties into a single material in order to obtain a highly stable polymer with a low band gap to meet the requirements for color variation. In that sense, two new donor acceptor type electrochromic copolymers of 2,3-bis(4-tert-butylphenyl)-5,8-di(1H-pyrrol-2-yl) quinoxaline (TBPPQ) with bis(3,4-ethylenedioxythiophene) (BiEDOT) and with 4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2-dodecyl-2H-benzo [1,2,3] triazole (BEBT) were synthesized by electrochemical polymerization. Polymers revealed multicolor electrochromic properties with distinct accessible states and low operation potentials. Electrochromic and kinetic properties of polymers were investigated using cyclic voltammetry (CV) and in situ UV–vis–NIR spectroscopy. [Copyright &y& Elsevier]

Abstract: Two low band gap conjugated polymers, poly[4,9-bis(4-hexylthien-2-yl)-6,7-di(thien-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline] (PHTTQ) and poly[5,10-bis(4-hexylthien-2-yl)-2,3,7,8-tetra(thien-2-yl)pyrazino[2,3-g]quinoxaline] (PHTPQ), consisting of alternating electron-rich 3-hexylthiophene and electron-deficient 6,7-di(thien-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline (TTQ) and 2,3,7,8-tetra(thien-2-yl)-2,3-dihydropyrazino[2,3-g]quinoxaline (TPQ) units were synthesized electrochemically. The structures of the π-conjugated monomers were tailored using thiophene as the pendant group on the acceptor units (TTQ and TPQ). The electrochemical and optical properties of the polymers were investigated by cyclic voltammetry and UV–vis–NIR spectroscopy. The absorption spectra of PHTPQ, revealing a 1.0eV band gap, exhibited three maxima at 352nm, 535nm, and 750nm. Consequently, its absorption spectra cover the region between 400 and 800nm, which make the polymer almost black in appearance. PHTTQ shows a λ max value of 820nm and a band gap of 0.8eV which is very low among other [1,2,5]thiadiazolo[3,4-g]quinoxaline-containing donor–acceptor type polymers. [Copyright &y& Elsevier]

Abstract: Two new quinoxaline and ethylenedioxythiophene (EDOT) based polymers; poly(5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2-(phenyll)-3-ferrocenylquinoxaline) (P1) and poly(5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2,3-di(naphthalen-2-yl) quinoxaline) (P2) were synthesized and characterized in terms of their electrochemical and spectroelectrochemical properties. The polymers were both p and n-type dopable. The polymers can be switched between green and transparent states during p-doping/dedoping. They were compared with their previously reported analogues in order to investigate ferrocene pendant group effect on electrochromic characteristics. [ABSTRACT FROM AUTHOR]

Abstract: Donor–acceptor–donor (DAD) type benzimidazole (BIm) and 3,4 ethylenedioxythiophene (EDOT) bearing monomers were synthesized and electrochemically polymerized. Pendant group at 2-C position of the imidazole ring was functionalized with phenyl (P1), EDOT (P2) and ferrocene (P3) in order to observe substituent effect on electrochemical and electrochromic properties of corresponding polymers. Spectroelectrochemical results showed that different pendant groups resulted in polymers with slightly different optical band gaps (1.75, 1.69 and 1.77 eV respectively) and different number of achievable colored states. Optoelectronic performance and comparison of results with other well known π-accepting benzazole bearing DAD type polymers were reported in detail. [ABSTRACT FROM AUTHOR]

Abstract: Two electroactive monomers 1-benzyl-4,7-di(thiophen-2-yl))-2H-benzo[d][1,2,3]triazole (BBTA) and 2-benzyl-4,7-di(thiophen-2-yl))-2H-benzo[d][1,2,3]triazole (BBTS) were synthesized with satisfactory yields. The effect of substitution site on electrochemical and optical properties was investigated with cyclic voltammetry and spectroelectrochemical studies. Results showed that position of pendant group alters the electronic structure of the resulting polymer causing different optical and electrochemical behaviors. Symmetrically positioned benzyl unit on benzotriazole moiety resulted in a neutral state red polymer, PBBTS, having multi-colored property in its different oxidized and reduced states. Its analogue PBBTA exhibited maximum absorption at 390nm in its neutral state and also revealed multicolored electrochromic property upon stepwise oxidation. Very different optical band gap values were calculated: 1.55eV and 2.25eV for PBBTS and PBBTA, respectively. [Copyright &y& Elsevier]