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Abstract: 2-Dodecyl benzotriazole (BTz) and benzothiadiazole (BTd) containing alternating copolymers poly(4-(2-dodecyl-2H-benzo[d][1,2,3]triazol-4-yl)benzo[c][1,2,5]thiadiazole (P1), poly(4-(5-(2-dodecyl-7-(thiophen-2yl)-2H-benzo[d][1,2,3]triazol-4-yl)thiophen-2-yl)benzo[c] [1,2,5] thiadiazole (P2) and poly(4-(5-(2-dodecyl-7-(4-hexylthiophen-2-yl)-2H-benzo[d] [1,2,3]triazol-4-yl) -3-hexylthiophen-2-yl) benzo[c][1,2,5] thiadiazole (P3) were synthesized via Suzuki polycondensation reactions. The solubility of the polymers enabled spray coating to carry out the electrochemical and optical studies. Electronic and optical properties of resulting polymers showed that P2 is a great candidate to be used as processable blue electrochromic polymer which can switch to transparent upon oxidation. P3 was also investigated in terms of its electrochromic performance which has two different colored and a transparent states, whereas P1 does not exhibit any spectral change upon applied potentials. HOMO and LUMO values, band gaps and kinetic behavior of polymers upon externally applied potential are reported in detail. [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: A benzothiadiazole bearing donor–acceptor–donor (D–A–D) type monomer (M3) was synthesized using the combination of 3, 4-ethylenedioxythiophene (EDOT) and thiophene donor units to understand the effect of donor strength on the optoelectronic and electrochemical properties. The resulting monomer was polymerized electrochemically (P3) and compared with its symmetrical thiophene (P1) and EDOT (P2) bearing homologues whether there exists a combination of the electrochemical and optical characteristics. Also, copolymer studies were performed with symmetrical thiophene (M1) and EDOT (M2) containing monomers in order to compare the results with P3. Cyclic voltammetry (CV) and spectroelectrochemistry results revealed that P3 is a low band gap polymer (1.18eV) having both p-and n-type property which is superior to the copolymers synthesized using M1 and M2. [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]

Abstract: New classes of EDOT coupled-benzotriazole bearing π-conjugated monomers containing benzyl units on electron-withdrawing benzotriazole moiety were synthesized. The effect of structural differences on electrochemical and optoelectronic properties of the resulting polymers (PBBTES and PBBTEA) was investigated. The results showed that the insertion of benzyl substituent to benzotriazole from different positions changes the electronic structure of polymer which results in completely different electrochemical and optical properties. PBBTES has a very low oxidation potential (0.13V) compared to the oxidation potential of PBBTEA (0.98V). Spectroelectrochemical analyses revealed that PBBTES is blue in its neutral state with a π–π* transition at 625nm whereas PBBTEA is orange in its neutral state with a π–π* transition at 477nm. The band gap (E g) values for PBBTES and PBBTEA were calculated as 1.48eV and 1.57eV, respectively. PBBTEA can be switched between blue neutral state and light blue oxidized state while PBBTEA reveals orange color at the neutral state and gray color at oxidized state. [Copyright &y& Elsevier]

Abstract: A new neutral state green polymer, poly (2,3-bis(4-tert-butylphenyl)-5,8-di(1H-pyrrol-2-yl) quinoxaline) (PTBPPQ) was synthesized and its potential use as an electrochromic material was investigated. Spectroelectrochemistry studies showed that polymer reveals two distinct absorption bands as expected for a donor–acceptor type polymer, at 408 and 745nm. In addition, polymer has excellent switching properties with satisfactory optical contrasts and very short switching times. Outstanding optical contrast in the NIR region and stability make this polymer a great candidate for many applications. It should be noted that PTBPPQ is one of the few examples of neutral state green polymeric materials with superior switching properties. Hence, PTBPPQ can be used as a green polymeric material for display technologies. [Copyright &y& Elsevier]