Substituent and heteroatom effects on the electrochromic properties of similar systems

Electrochromic polymers called poly(3,4‐dihydro‐3,3‐bis ((naphthalen‐1‐yl)methyl)‐2H‐thieno[3,4‐b][1,4]dioxepine) (PProDOT‐Np₂), poly(3,3‐dibenzyl‐3,4‐dihydro‐2H‐selenopheno[3,4‐b][1,4]dioxepine), and poly(3,3‐dibenzyl‐3,4‐dihydro‐2H‐thieno[3,4‐b][1,4]dioxepine) were synthesized electrochemically and the effect of substituents and heteroatoms on the electrochromic properties were investigated for the similar systems. All polymers show electrochromism from a colored state when neutralized to transmissive when oxidized. Although, increasing bulky size (PProDOT‐Np₂) causes lower coloration efficiency (CE) as well as lower optical contrast, the replacement of S atom by Se atom resulted in a lower band gap polymer with a higher CE than its thiophene analog. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

[1,2,5]thiadiazolo[3,4‐g]quinoxaline acceptor‐based donor–acceptor–donor‐type polymers: Effect of strength and size of donors on the band gap

Electrochromic polymers based on [1,2,5]thiadiazolo[3,4‐g]quinoxaline acceptor and thiophene, 3,4‐ethylenedioxythiophene and 3,3‐didecyl‐3,4‐proylenedioxythiophene donors, namely poly(6,7‐diphenyl‐4,9‐di(thiophen‐2‐yl)‐[1,2,5]thiadiazolo[3,4‐g]quinoxaline) ( P1 ), poly(4‐(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐5‐yl)‐9‐(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐7‐yl)‐6,7‐diphenyl‐[1,2,5]thiadiazolo[3,4‐g]quinoxaline) ( P2 ), and poly(4‐(3,3‐didecyl‐3,4‐dihydro‐2H‐thieno[3,4‐b][1,4]dioxepin‐6‐yl)‐9‐(3,3‐didecyl‐3,4‐dihydro‐2H‐thieno[3,4‐b][1,4]dioxepin‐8‐yl)‐6,7‐diphenyl‐[1,2,5]thiadiazolo[3,4‐g]quinoxaline) ( P3 ), respectively, were electrochemically and/or chemically synthesized and characterized. Electrochemical and optical properties of the polymers were then investigated. The results, which were obtained electrochemically and optically, indicate that the polymers bearing the same acceptor and different donor units have a band gap range of 0.59–1.24 eV depending on the strength and size of the donor units and band gap determination method. A significant finding in this study was the phenomenon that when the acceptor is physically huge, the general rule that a weak donor would have a high band gap whereas a strong donor would have low band gap can be broken due to the torsional angles/steric hindrances involved with physically large donor molecules. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3483–3493     

Synthesis and characterization of isoindigo‐based polymers using CH‐arylation polycondensation reactions for organic photovoltaics

A series of three new low bandgap donor–acceptor–donor–acceptor^/ (D–A–D–A^/) polymers have been successfully synthesized based on the combination of isoindigo as the electron‐deficient acceptor and 3,4‐ethylenedioxythiophene as the electron‐rich donor, followed by CH‐arylation with different acceptors (4,7‐dibromo[c][1,2,5]‐(oxa, thia, and/or selena)diazole ( 4a‐c )). These polymers were used as donor materials for photovoltaic applications. All of the polymers are highly stable and show good solubility in chlorinated solvents. The highest power conversion efficiency of 1.6% was achieved in the bulk heterojunction photovoltaic device that consisted of poly ((E)?6‐(7‐(benzo‐[c][1,2,5]‐thiadiazol‐4‐yl)?2,3‐dihydrothieno‐[3,4‐b][1,4]dioxin‐5‐yl)?6′‐(2,3‐dihydrothieno‐[3,4‐b][1,4]‐dioxin‐5‐yl)?1,1′‐bis‐(2‐octyldodecyl)‐[3,3′‐biindolinylidene]‐2,2′‐dione) as the donor and PC₆₁BM as the acceptor, with a short‐circuit current density (J_sc) of 8.10 mA/cm², an open circuit voltage (V_oc) of 0.56 V and a fill factor of 35%, which indicates that these polymers are promising donors for polymer solar cell applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2926–2933     

Poly(ProDOT‐Et2): A High‐Contrast,High‐Coloration Efficiency Electrochromic Polymer

The synthesis and electrochemical polymerization of 3,3‐diethyl‐3,4‐dihydro‐2H‐thieno‐[3,4‐b][1,4]dioxepine (ProDOT‐Et₂) was performed resulting in a stable electrochromic polymer capable of switching between an absorbing blue neutral state and a highly transmissive sky‐blue oxidized state in sub‐second time frames. High optical switching contrast ratios (up to 75% at λ_max) and high composite coloration efficiencies (505 cm²/C) were measured.     

High fluorescent ethyl acrylate modified PEDOT‐MeNH2 with enhanced electrochromic performance

Two poly(2'‐aminomethyl‐3,4‐ethylenedioxythienylene) (PEDOT‐MeNH₂) derivatives were successfully synthesized by electrochemical polymerization of precursors, diethyl 3'‐(((2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐2‐yl) methyl)azanediyl)dipropanoate ( monomer 1 ) and ethyl 3‐(((2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐2‐yl) methyl)amino)propanoate ( monomer 2 ), respectively. Structure–property relationships of monomers and polymers, including electrochemical, optical properties, and morphology, were systematically explored. Significantly, the designed polymers exhibited red and orange emission signatures with high fluorescence quantum yields (Φ_F) of 0.044 and 0.045 compared with those of monomers; they may be used as building blocks for rational design of fluorescent materials. Moreover, cyclic voltammetry and spectroelectrochemistry studies demonstrated that poly(diethyl 3'‐(((2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐2‐yl)methyl)azanediyl) dipropanoate) ( P1 ) and poly(ethyl 3‐(((2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐2‐yl)methyl)amino) propanoate) ( P2 ) can be reversibly oxidized and reduced accompanied by obvious color changes from light purple to light blue for P1 , and from purple to blue for P2 . Furthermore, both P1 and P2 displayed higher optical contrasts (40–70%) in the visible region, favorable coloration efficiency (typically 50–230 cm² C^?1). From these results, the two polymers would be promising candidate materials for display applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2081–2091     

Multichromic benzimidazole‐containing polymers: Comparison of donor and acceptor unit effects

This study reports a comparative study on electrochromic properties of two donor–acceptor–donor (DAD)‐type polymers namely poly(2‐heptyl‐4,7‐di(thiophen‐2‐yl)‐1H‐benzo [d]imidazole) (BImTh) and poly(4,7‐bis(2,3‐dihydrothieno[3,4‐b] [1,4]dioxin‐5‐yl)‐2‐heptyl‐1H‐benzo[d]imidazole) (BImEd). DAD‐type monomers were polymerized electrochemically on indium tin oxide‐coated glass slides to determine the optical properties of the polymers. Electrochemical p‐doping experiments were performed to determine the band gap and absorption band values of the polymer films at different redox states. Polymerization of BImTh and BImEd yields multichromic polymers. Donor and acceptor effects are studied by comparing the PBImEd and PBImTh with corresponding benzotriazole derivatives. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Fused structures in the polymer backbone to investigate the photovoltaic and electrochromic properties of donor–acceptor‐type conjugated polymers

In this study, two new benzotriazole (BTz) and dithienothiophene (DTT) containing conjugated polymers were synthesized. After successful characterizations of the monomers by proton‐nuclear magnetic resonance (¹H NMR) and carbon‐NMR (¹³C NMR) techniques, poly(4‐(dithieno[3, 2‐b:2′,3′‐d]thiophen‐2‐yl)‐2‐(2‐octyldodecyl)‐2H‐benzo[d][1,2,3] triazole) P1 and poly(4‐(5‐(dithieno[3,2‐b:2′,3′‐d]thiophen‐2‐yl)thiophen‐2‐yl)‐2‐(2‐octyldodecyl)‐7‐(thiophen‐2‐yl)‐2H‐benzo[d][1,2,3]triazole) P2 were synthesized via a typical Stille coupling. Electrochemical and spectroelectrochemical studies showed that both polymers can be multipurpose materials and used in electrochromic and photovoltaic applications. Reported study indicated that incorporation of DTT into the structure leads to fast switching times compared with BTz‐based polymers and competent percentage transmittance in the near‐infrared region. Multichromism is important in the context of low‐cost flexible display device technology and both polymers are ambipolar and processable as well as multichromic. Throughout the preliminary photovoltaic studies, the best performances of photovoltaic devices were found as V_oc = 0.49 V, J_sc = 0.83 mA/cm², fill factor (FF) = 34.4%, and power conversion efficiency (PCE) = 0.14% for P1 , and as V_oc = 0.35 V, J_sc = 1.57 mA/cm², FF = 38.2%, and PCE = 0.21% for P2 . © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Syntheses and optoelectronic properties of quinoxaline polymers: The effect of donor unit

Tuning the bandgap of electrochromic polymers is one of the important research topics in electrochromism. To understand clearly the effect of donor unit in donor–acceptor–donor‐type polymers, 2,3‐bis(4‐tert‐butylphenyl)‐5,8‐di(thiophen‐2‐yl)quinoxaline and 2,3‐bis(4‐tert‐butylphenyl)‐5‐(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐ 5‐yl)‐8‐(thiophen‐2‐yl)quinoxaline were synthesized and polymerized potentiodynamically. Their electrochemical and spectroelectrochemical studies were performed, and the results were compared with those of poly(2,3‐bis(4‐tert‐butylphenyl)‐5,8‐bis(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐5‐yl)quinoxaline) (Gunbas et al., Adv Mater 2008, 20, 691–695). A blue shift in the polymer π–π* transitions revealed that the bandgap of such polymers with the same acceptor unit is related to the electron density of donor units. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Design and synthesis of 9,9‐dioctyl‐9H‐fluorene based electrochromic polymers

Two novel heterocycle‐fluorene‐heterocycle monomers, 2,2′‐(9,9‐dioctyl‐9H‐fluorene‐2,7‐diyl)dithiophene (Th‐F‐Th) and 5,5′‐(9,9‐dioctyl‐9H‐fluorene‐2,7‐diyl)bis(2,3‐dihydrothieno[3,4‐b][1,4]dioxine) (EDOT‐F‐EDOT), were synthesized via Stille coupling reaction and electropolymerized to form corresponding polymers P(Th‐F‐Th) and P(EDOT‐F‐EDOT). Furthermore, the optoelectronic properties of the obtained monomers and polymers were explored using cyclic voltammetry (CV), UV–vis, and emission spectra and in situ spectroelectrochemical techniques. The band gap values of monomers calculated by DFT were 3.75 eV for EDOT‐F‐EDOT and 4.03 eV for Th‐F‐Th, while that of P(EDOT‐F‐EDOT) and P(Th‐F‐Th) were brought down to 1.70 and 2.10 eV, respectively. Both polymers exhibited excellent redox activity and electrochromic performance. P(EDOT‐F‐EDOT) exhibited a maximum optical contrast of 25.8% at 500 nm in visible region with a response time of 1.2 s. In addition, the coloration efficiency of P(EDOT‐F‐EDOT) was calculated to be 220 cm² C^?1. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 325–334     

Novel chiral PEDOTs for selective recognition of 3,4‐dihydroxyphenylalanine enantiomers: Synthesis and characterization

Two new 3,4‐ethylenedioxythiophene (EDOT) derivatives, (2R)‐(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐2‐yl)methyl 2‐phenylpropanoate ((R)‐EDTM‐PP) and (2S)‐(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐2‐yl)methyl 2‐phenylpropanoate ((S)‐EDTM‐PP), were synthesized and electropolymerized in dichloromethane (CH₂Cl₂) and terabutylammonium hexafluorophosphate (Bu₄NPF₆) system. As chiral electrodes, poly((2R)‐(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐2‐yl)methyl 2‐phenylpropanoate) ((R)‐PEDTM‐PP) and poly((2S)‐(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐2‐yl)methyl 2‐phenylpropanoate) ((S)‐PEDTM‐PP)‐modified glassy carbon electrodes (GCEs) were employed to successfully recognize 3,4‐dihydroxyphenylalanine (DOPA) enantiomers. Cyclic voltammetry presents that (R)‐PEDTM‐PP and (S)‐PEDTM‐PP had good redox activity and stability. Spectroelectrochemistry studies revealed (R)‐PEDTM‐PP and (S)‐PEDTM‐PP polymers have electronic bandgap of 1.68 and 1.66 eV, and could be reversibly oxidized and reduced accompanying with obvious color changes from dark blue to light purple. In addition, the electrochemical behavior, structural characterization, thermal stability, morphology and circular dichroism of (R)‐PEDTM‐PP and (S)‐PEDTM‐PP films were investigated in detail. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2238–2251     

Donor–acceptor‐structured naphtodithiophene‐based copolymers for organic thin‐film transistors

New donor–acceptor (D‐A) polymers, poly(4,5‐bis(2‐octyldodecyloxy)naphto[2,1‐b:3,4‐b']dithiophenebenzo[c][1,2,5]thiadiazole) (PNDT‐B) and poly(4,5‐bis(2‐octyldodecyloxy)naphto [2,1‐b:3,4‐b′]dithiophene‐4,7‐di(thiophen‐2‐yl)benzo[c][1,2,5]thiadiazole) (PNDT‐TBT), with the extended π‐electron delocalization of naphtho[2,1‐b:3,4‐b']dithiophene, were successfully synthesized by Suzuki and Stille coupling reactions. The structure and physical properties of polymers were characterized by DFT calculation, UV–vis absorption, cyclovoltammetry, TGA and DSC analyses. X‐ray diffraction studies indicated a relatively highly ordered intermolecular structure in PNDT‐TBT after annealing. This high degree of molecular order resulted from the crystallinity and increasing planarity, provided by the thiophene linker groups and the interdigitation of the long alkoxy side chains. The new D‐A polymer, PNDT‐TBT, exhibited a p‐type carrier mobility of 0.028 cm²/Vs and an on/off ratio of 5.9 × 10³. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 525–531     

Synthesis and photovoltaic properties of thieno[3,4‐b]pyrazine or dithieno[3′,2′:3,4;2″,3″:5,6]benzo[1,2‐d]imidazole‐containing conjugated polymers

Novel conjugated polymers composed of benzo[1,2‐b:4,5‐b′]dithiophene and thieno[3,4‐b]pyrazine or dithieno[3′,2′:3,4;2″,3″:5,6]benzo[1,2‐d]imidazole units are synthesized by Stille polycondensation. The resulting polymers display a longer wavelength absorption and well‐defined redox activities. The effective intramolecular charge‐transfer and energy levels of all polymers are elucidated by computational calculations. Bulk‐heterojunction solar cells based on these polymers as p‐type semiconductors and [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PC₆₁BM) as an n‐type semiconductor are fabricated, and their photovoltaic performances are for the first time evaluated. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1067–1075     

High‐performance amorphous donor–acceptor conjugated polymers containing x‐shaped anthracene‐based monomer and 2,5‐bis(2‐octyldodecyl)pyrrolo[3,4‐c]pyrrole‐1,4(2H,5H)‐dione for organic thin‐film transistors

New diketopyrrolopyrrole (DPP)‐containing amorphous conjugated polymers, such as poly(3‐(5‐((9,10‐bis((4‐hexylphenyl)ethynyl)‐6‐(prop‐1‐ynyl)anthracen‐2‐yl)ethynyl) thiophen‐2‐yl)‐5‐(2‐hexyldecyl)‐2‐(2‐octyldodecyl)‐6‐(thiophen‐2‐yl)pyrrolo[3,4‐c]pyrrole‐1,4(2H,5H)‐dione) ( 4 ), and poly(3‐(5‐((2,6‐bis((4‐hexylphenyl)ethynyl)‐10‐(prop‐1‐ynyl)anthracen‐9‐yl)ethynyl)thiophen‐2‐yl)‐2,5‐bis(2‐octyldodecyl)‐6‐(thio phen‐2‐yl)pyrrolo[3,4‐c]pyrrole‐1,4(2H,5H)‐dione) ( 7 ), were successfully synthesized via Sonogashira coupling reactions under microwave conditions. Copolymer 7 , incorporating a DPP moiety at the 9,10‐position of the anthracene ring through a triple bond, showed a much lower bandgap energy (E_g = 1.81 eV) than copolymer 4 (E_g = 2.13 eV). Tuning of the molecular frontier orbital energies was achieved by only changing the anchoring position of dithiophenyl‐DPP from the 2,6‐ to the 9,10‐position in the anthracene ring. Because of the donor–acceptor (D–A) interaction and the two‐dimensional planar structure of the X‐shaped donor monomer, the resulting polymers showed good interchain π?π stacking in the thin‐film state, despite being amorphous polymers. When the newly synthesized polymer 7 was used as a semiconductor material in an organic thin‐film transistor, the best mobility of up to 0.12 cm² V^?1 s^?1 (I_on/off = ～ 4.4 × 10⁶) was observed, which is one of the highest values recorded for amorphous polymer films reported to date. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Electrochromic enhancement of poly(3,4‐ethylenedioxythiophene) films functionalized with hydroxymethyl and ethylene oxide

2‐((2,3‐Dihydrothieno[3,4‐b]dioxin‐2‐yl)methoxy)methyl oxirane (EDOT‐MO) was successfully synthesized by the reaction of epichlorohydrin with hydroxymethylated‐3,4‐ethylenedioxylthiophene (EDOT‐MeOH), which was synthesized via a simple four‐step sequence. Poly(hydroxymethylated‐3,4‐ethylenedioxylthiophene) (PEDOT‐MeOH) and poly(2‐((2,3‐dihydrothieno[3,4‐b]dioxin‐2‐yl)methoxy)methyl oxirane) (PEDOT‐MO) were electrosynthesized through electropolymerization of EDOT‐MeOH and EDOT‐MO, respectively. Structural, electrochemical, optical, and thermal properties of as‐formed polymers were investigated by FTIR, cyclic voltammetry, UV–vis, and thermogravimetry. Spectroelectrochemistry studies demonstrated that PEDOT‐MeOH and PEDOT‐MO could be reversibly oxidized and reduced accompany with obvious color changes. Further kinetic studies demonstrated that the introduction of hydroxymethyl or ethylene oxide group significantly improved electrochromic properties of 3,4‐ethylenedioxythiophene (PEDOT) and resulted in high contrast ratios (57.3% at 585 nm) and coloration efficiencies (338.5 cm² C^?1), low switching voltages, and fast response time. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1989–1999     

Crosslinked polyamide based on main‐chain type polybenzoxazines derived from a primary amine‐functionalized benzoxazine monomer

Two types of main‐chain type polybenzoxazines with amide and benzoxazine groups as repeating units in the main chain, termed as poly(amide‐benzoxazine), have been synthesized. They have been prepared by polycondensation reaction of primary amine‐bifunctional benzoxazine with adipoyl and isophthaloyl dichloride using dimethylacetamide as solvent. Additionally, a model reaction is designed from the reaction of 3,3′‐(4,4′‐methylenebis(4,1‐phenylene))bis(3,4‐dihydro‐2H‐benzo[e][1,3]oxazin‐6‐amine) with benzoyl chloride. The structures of model compound and polyamides are confirmed by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (¹H NMR) spectroscopies. Differential scanning calorimetry and FTIR are also used to study crosslinking behavior of both the model compound and polymers. Thermal properties of the crosslinked polymers are also studied by thermogravimetric analysis. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Poly(1,4‐diketo‐3,6‐diphenylpyrrolo[3,4‐c]pyrrole‐alt−3,6‐carbazole/2,7‐fluorene) as high‐performance two‐photon dyes

This article reports the synthesis, one‐ and two‐photon absorption, and excited fluorescence properties of poly(1,4‐diketo‐3,6‐diphenylpyrrolo[3,4‐c]pyrrole‐alt‐N‐octyl‐3,6‐carbazole/2,7‐fluorene) ( PDCZ / PDFL ). PDCZ and PDFL are synthesized by the Suzuki cross‐coupling of 2,5‐dioctyl‐1,4‐diketo‐3,6‐bis(p‐bromophenylpyrrolo[3,4‐c]pyrrole and N‐octyl‐3,6‐bis(3,3‐dimethyl‐1,3,2‐dioxaborolan‐2‐yl)carbazole or 2,7‐bis(3,3‐dimethyl‐1,3,2‐dioxaborolan‐2‐yl)fluorene and have number‐average molecular weights of 8.5 × 10³ and 1.14 × 10⁴ g/mol and polydispersities of 2.06 and 1.83, respectively. They are highly soluble in common organic solvents and emit strong orange one‐ and two‐photon excited fluorescence (2PEF) in THF solution and exhibit high light and heat stability. The maximal two‐photon absorption cross‐sections (δ) measured in THF solution by the 2PEF method using femtosecond laser pulses are 970 and 900 GM per repeating unit for PDCZ and PDFL , respectively. These 1,4‐diketo‐pyrrolo[3,4‐c]pyrrole‐containing polymers with full aromatic structure and large δ will be promising high‐performance 2PA dyes applicable in two‐photon science and technology. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 944–951     

Synthesis and properties of fluorene‐based polyheteroarylenes for photovoltaic devices

Novel copolymers consisting of the alternating push–pull comonomers fluorene and thieno[3,4‐b]pyrazine/quinoxaline were synthesized by a palladium‐catalyzed Suzuki cross‐coupling reaction in 60–80% yields. The structure of the deeply colored copolymers was confirmed with ¹H and ¹³C NMR. All the new materials were characterized with spectroscopic and electrochemical methods. Bulk heterojunction organic solar cells based on some of the novel polymers in combination with the well‐known fullerene acceptor [6,6]‐phenyl C₆₁–butyric acid methyl ester were fabricated, and their photovoltaic parameters were measured. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6952–6961, 2006     

Dehydrocoupling and Diels–Alder reactions on siloxane polymers

Dehydrocoupling reactions between linear poly(methylhydrosiloxane) {Me₃SiO–[MeSi(H)O]_n–SiMe₃} and alcohols such as cholesterol, anthracene‐9‐carbinol, (12‐crown‐4)‐2‐carbinol, pyrene‐1‐carbinol, 4‐methyl‐5‐thiazoleethanol, and 4‐pyridilpropanol were introduced under catalytically mild conditions. The degrees of conversion of Si? H bonds in polysiloxane were monitored with ¹H NMR spectra. The reaction of the 9‐methoxyanthracene adduct on siloxane polymers and maleimide derivatives (maleimide, N‐ethylmaleimide, and maleic acid anhydride) produced [2+4]‐cycloadducts in very high yields. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4013–4019, 2002     

Synthesis and electrochromic properties of triphenylamine containing copolymers: Effect of π‐bridge on electrochemical properties

In this study, a series of benzotriazole (BTz) and triphenylamine (TPA)‐based random copolymers; poly4‐(5‐(2‐dodecyl‐7‐methyl‐2H‐benzo[d][1,2,3]triazol‐4‐yl)thiophen‐2‐yl)‐N‐(4‐(5‐methylthiophen‐2‐yl)phenyl)‐N‐phenylaniline ( P1 ), poly4′‐(2‐dodecyl‐7‐methyl‐2H‐benzo[d][1,2,3]triazol‐4‐yl)‐N‐(4′‐methyl‐[1,1′‐biphenyl]‐4‐yl)‐N‐phenyl‐[1,1′‐biphenyl]‐4‐amine ( P2 ), and poly4‐(5′‐(2‐dodecyl‐7‐(5‐methylthiophen‐2‐yl)?2H‐benzo[d][1,2,3]triazol‐4‐yl)‐[2,2′‐bithiophen]‐5‐yl)‐N‐(4‐(5‐methylthiophen‐2‐yl)phenyl)‐N‐phenylaniline ( P3 ) were synthesized to investigate the effect of TPA unit and π‐bridges on electrochemical and spectroelectrochemical properties of corresponding polymers. The synthesis was carried out via Stille coupling for P1 , P3 , and Suzuki coupling for P2 . Electrochemical and spectral results showed that P1 has an ambipolar character, in other words it is both p‐type and n‐type dopable, whereas P2 and P3 have only p‐doping property. Effect of different π‐bridges and TPA unit on the HOMO and LUMO energy levels, switching time, and optical contrast were discussed. All polymers are promising materials for electrochromic devices. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 537–544     

Spray‐processable thiazolothiazole‐based copolymers with altered donor groups and their electrochromic properties

Two novel thiazolo[5,4‐d]thiazole containing donor–acceptor type alternating copolymers, poly[2‐(5‐(2‐decyl‐2H‐benzo[d][1,2,3]triazol‐4‐yl)thiophen‐2‐yl)‐5‐(thiophen‐2‐yl)thiazolo[5,4‐d]thiazole] (BTzTh) and poly[2‐(5‐(2‐decyl‐2H‐benzo[d][1,2,3]triazol‐4‐yl)furan‐2‐yl)‐5‐(furan‐2‐yl)thiazolo[5,4‐d]thiazole] (BTzFr) were synthesized by Stille coupling polymerization and their electrochemical and electrochromic properties were explored. Electrochemical activities of the spray‐casted polymer films were determined by cyclic voltammetry. To evaluate the effect of thiophene and furan moieties on the optical properties of the copolymers, spectroelectrochemistry studies were performed. To examine the switching abilities, copolymer films were subjected to a double potential step chronoamperometry in their local maximum absorptions. Both thiazolothiazole‐containing copolymers showed multichromic properties with low band‐gap values 1.7 and 1.9 eV for BTzTh and BTzFr, respectively. The decent electrochromical properties together with solution processability make them important candidates for electrochromic applications. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3901–3906