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We designed a new fluorescent conjugated polymer thin film sensor via direct electropolymerization of the corresponding electroactive monomer M onto the surface of ITO electrode, and the thin film-Fe 3+ complex was used for the highly-selective detection of fluoride ion (F − ) in water environmental samples. The as-obtained thin film could effectively detect Fe 3+ as a selective turn-off fluorescent sensor, and exhibited outstanding reversibility. This film in the presence of Fe 3+ showed a highly selective turn-on response toward F − over other anions with a 5-fold enhancement in the fluorescence intensity. F − with a relatively wide concentration range from 10 μM to 3 mM could be determined in a rather simple and sensitive manner with a detection limit of 6.78 μM (0.128 ppm). Analytical applicability of the film-Fe 3+ complex for determining the levels of F − in environmental water samples has been successfully demonstrated by fluorescent analysis with satisfactory results. This strategy will provide a new approach for the facile design of new molecular sensing devices and practical application in environments. [ABSTRACT FROM AUTHOR]

In this paper, poly[poly( N-vinyl-carbazole)] (PPVK) films electrodeposited in tetrahydrofuran (THF) containing 12 % boron trifluoride diethyl etherate (BFEE) were studied as electrode active material for supercapacitors. The morphology and thermal property were characterized by SEM, atomic force microscopy (AFM), and thermogravimetry (TG), respectively. The electrochemical capacitive behaviors of the PPVK films were also investigated by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The electrochemical results showed that the specific capacitance of PPVK films in CHCN solution was about 126 mF cm at 1.5 mA cm and the capacitance retention was only 14.4 % after 1000 cycles. It was exciting to improve the specific capacitance up to 169.3 mF cm at 1.5 mA cm and to make the cyclic stability increase to 81.8 % capacitance retention after 5000 cycles when the equivalent BFEE was added into the CHCN solution containing 0.05 M BuNBF electrolyte. These results clearly demonstrated that BFEE was an efficient promoter for the enhancement of the capacitance performance of PPVK films. Therefore, with the help of BFEE electrolyte, the PPVK films have potential application as capacitive materials in high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

A fluorescent conjugated polymer thin film sensor via the electropolymerization for fluorescent detection of Fe 3+ in aqueous solution was successfully fabricated using a poly(5-cyanoindole) (P5CI), which was electrochemically prepared in the mixed electrolyte of boron trifluoride diethyl etherate, diethyl ether and tetrabutylammonium tetrafluoroborate on ITO electrodes by successive cyclic voltammetry. The thickness of the electropolymerized P5CI thin film could be precisely controlled by optimizing scan cycles and scan rates. The as-obtained fluorescent P5CI thin film sensor could effectively recognize Fe 3+ with outstanding sensitivity, selectivity, reversibility and reproducibility over other commonly coexistent metal ions and anions, and realize the quantitative determination of Fe 3+ in a linear range of 0.2 μM–0.5 mM with a detection limit of 0.897 ppb. The reversibility and reproducibility of P5CI thin film sensor were assessed. Satisfactory results indicated that fluorescent conjugated polymers via the electropolymerization provided a promising candidate for fluorescent thin film sensor. [ABSTRACT FROM AUTHOR]

Theasymmetrical sulfur analog of 3,4-ethylenedioxythiophene (EDOT),thieno[3,4-b]-1,4-oxathiane (EOTT), was synthesized,and its electropolymerization was comparatively investigated by employingdifferent solvent–electrolyte systems (room temperature ionicliquid 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF6), CH2Cl2–Bu4NPF6, and CH2Cl2–BmimPF6). Further, the effect of solvents and supporting electrolytes onthe structure, morphology, electrochemical, electronic, and opticalproperties and electrochromic performance of the obtained poly(thieno[3,4-b]-1,4-oxathiane) (PEOTT) films were minutely studied. PEOTTfilm with a band gap (Eg) of about 1.6eV could be facilely electrodeposited in all the solvent-electrolytesand displayed excellent electroactivity, outstanding redox stabilityin a wide potential window, and improved thermal stability. Cyclicvoltammetry showed that EOTT could be electropolymerized at a loweroxidation potential in BmimPF6(∼1.0 V vs Ag/AgCl)due to several advantanges of RTIL BmimPF6itself, suchas high intrinsic conductivity and mild chemical conditions, etc.,and the resulting PEOTT film exhibited compact morphology with betterelectroactivity and stability and higher electrical conductivity.On the other hand, PEOTT films from all the sovent-electrolytes alsoshowed the electrochromic nature by color changing from gray blueto green, and further kinetic studies revealed that PEOTT had decentcontrast ratios (36%), higher coloration efficiencies (212 cm2/C in BmimPF6), low switching voltages, moderateresponse time (1.2 s), excellent stability, and color persistence.From these results, PEOTT provides more plentiful electrochromic colorsand holds promise for display applications. [ABSTRACT FROM AUTHOR]

Abstract: The electrosyntheses of poly(3-methoxythiophene) (PMOT) by direct anodic oxidation of MOT in novel ionic liquid microemulsions, BmimPF6/Tween 20/H2O, have been investigated. Among water-in-BmimPF6 (W/IL), bicontinuous (BC), and BmimPF6-in-water (IL/W) sub-regions, IL/W was found to be the most suitable medium for the electropolymerization of MOT. The use of IL/W microemulsions remarkably reduces the amount of IL, which is really expensive as electrolyte. BmimPF6 serves both as the core of IL/W microemulsions and as the supporting electrolyte and thus presents a novel microenvironment for the electropolymerization of MOT. Thus, MOT microdroplets were assembled on a bare ITO electrode and polymerized into PMOT microcups. In addition, the oxidation onset potential of MOT in IL/W microemulsions was lower than that in micellar aqueous solutions or conventional organic solvents. As-formed PMOT films obtained in IL/W microemulsions had an electrical conductivity of 3.8S/cm and could be dissolved in many conventional organic solvents, including dichloromethane, chloroform, acetonitrile, and dimethyl sulfoxide with green-light emitting property. [Copyright &y& Elsevier]

[Display omitted] • We develop a PEDOT-MeOH:PSS/PDA interface by a two-step electropolymerization method. • The prepared interface shows strong adhesion with 93% area retention after sonication for 20 min. • We further demonstrate the PEDOT-MeOH:PSS/PDA interface integrated on an ultrasmall Pt-Ir wire microelectrode with a diameter of only 10 μm. • The modified implantable neural microelectrodes display two orders of magnitude lower impedance than commercial products, and also superior long-term stability after 10,000,000 biphasic input pulse cycles. Conducting polymers are emerging as promising neural interfaces towards diverse applications such as deep brain stimulation due to their superior biocompatibility, electrical, and mechanical properties. However, existing conducting polymer-based neural interfaces still suffer from several challenges and limitations such as complex preparation procedures, weak interfacial adhesion, poor long-term fidelity and stability, and expensive microfabrication, significantly hindering their broad practical applications and marketization. Herein, we develop an adhesive and long-term stable conducting polymer neural interface by a simple two-step electropolymerization methodology, namely, the pre-polymerization of polydopamine (PDA) as an adhesive thin layer followed by electropolymerization of hydroxymethylated 3,4-ethylenedioxythiophene (EDOT-MeOH) with polystyrene sulfonate (PSS) to form stable interpenetrating PEDOT-MeOH:PSS/PDA networks. As-prepared PEDOT-MeOH:PSS/PDA interface exhibits remarkably improved interfacial adhesion against metallic electrodes, showing 93% area retention against vigorous sonication for 20 min, which is one of the best tenacious conducting polymer interfaces so far. Enabled by the simple methodology, we can facilely fabricate the PEDOT-MeOH:PSS/PDA interface onto ultrasmall Pt-Ir wire microelectrodes (diameter: 10 μm). The modified microelectrodes display two orders of magnitude lower impedance than commercial products, and also superior long-term stability to previous reports with high charge injection capacity retention up to 99.5% upon 10,000,000 biphasic input pulse cycles. With these findings, such a simple methodology, together with the fabricated high-performance and stable neural interface, can potentially provide a powerful tool for both advanced neuroscience researches and cutting-edge clinical applications like brain-controlled intelligence. [ABSTRACT FROM AUTHOR]

Most recently, bithiophene unit has became a good choice as monomer unit for alternating π-conjugated copolymers for optoelectronic materials, because it gives good charge mobility to the corresponding polymers and serves as an appropriate donor unit in donor–acceptor polymers with narrow energy band gap. Herein, in order to get a comprehensively understanding of the structure–property relationship of the bithiophene based comonomers and copolymers, five hybrid oligomers which employed alkyl (C n H 2 n + 1 , n = 0, 1, 6, 8, 12) functionalized bithiophene unit as the core and 3,4-ethylenedioxythiophene unit as the terminals were synthesized. Structure–property relationships of these oligomers and the corresponding polymers were analyzed by optical, electrochemical techniques, theoretical calculations, and spectroelectrochemistry. It was found that as the pendant alkyl length increased from the H to the hexyl, the electronic spectra of these oligomers were blue-shifted while the fluorescence quantum yield reduced and the oxidation peaks were positively shifted. When the number of carbon atoms in the linear alkyl chain was higher than six, these values of them became almost stable. Density functional theory calculations confirmed these trends by comparing with the dihedral angles of each oligomer because of the steric effect caused by alkyl substitution. And the steric hindrance of the alkyl substitution still remains in the polymer films although the effects are very slight. These results clearly indicated that by the simple alky chain engineering, the optoelectronic and electrochemical properties of the oligo-/polythiophenes would be tuned due to the steric hindrance of the alkyl substituent. The hybrid polymers with band gap range from 1.75 to 1.83 eV and electrochromic nature with color changing from violet and purplish in the reduced form to transparent sky blue/green upon oxidation. Combining with good stability and favorable electrochemical activity, these materials hold promise for electrochromic devices and display applications. [ABSTRACT FROM AUTHOR]

Abstract: Polyselenophenes, which are extensively employed in organic electronics most recently, exhibit several special properties and potential advantages over polythiophenes as thermoelectric materials, such as lower band gap, higher carrier mobility, stronger intermolecular interactions, etc. This paper herein investigated the thermoelectric performances of different types of polyselenophene (PSE) prepared by different methods/conditions. Surprisingly, PSE exhibits very high Seebeck coefficient (>180μV K-1) despite its relatively low electrical conductivity (10-5∼10-2 S cm-1) at room temperature. To improve its electrical conductivity, the electrochemical copolymerization of selenophene (SE) with 3-methylthiophene under different feed ratios in boron trifluoride diethyl etherate (BFEE) was further investigated. The as-formed free-standing copolymer films showed a remarkable increase in electrical conductivity (100∼101 S cm-1) but a loss in Seebeck coefficient (45∼98μV K-1). Its maximum thermoelectric figure-of-merit ZT value was estimated to be as high as 3.4×10-2, much higher than those of the most organic thermoelectric materials reported previously. With the high Seebeck coefficient now reported, future work may focus on fully describing new polyselenophenes and polyselenophenes-based copolymers and further exploring their thermoelectric properties. [Copyright &y& Elsevier]

Summary: Poly(2,7‐bis(carbazol‐9‐yl)‐9,9‐dimethylfluorene) (PBCMF) polymer with porous structure was fabricated, and its electropolymerization was studied comparatively in dichloromethane (CH2Cl2) systems in the presence of different contents of boron trifluoride diethyl etherate (BFEE). When adding BFEE in CH2Cl2 solution, the oxidation potential of BCMF could be decreased obviously. When the content of BFEE increased to 40%, BCMF was oxidized at 0.47 V, while it was oxidized at 1.07 V in pure CH2Cl2 solution. A series of experiments showed that the polymer PBCMF films could be easily obtained in CH2Cl2‐BFEE systems, and films obtained from the 40 vol% BFEE system showed best electrochemical behavior and best fluorescence property. Fourier transform infrared spectra and UV‐Vis proved the longer conjugated chains of polymers. And scanning electron microscopy images of polymer films showed that all these polymer films made from BFEE systems had a good porous structure. [ABSTRACT FROM AUTHOR]

Electrochromic technologies require electrochromic π-conjugated polymers to reversibly transition between highly transmissive and broadly absorbing achromatic states, fast response time, and high kinetic stability. In this work, yellow-to-transmissive electrochromic poly(dibenzothiophene/dibenzofuran-bithiophene) (PDBT-2Th and PDBF-2Th) were prepared by electropolymerization of monomers DBT-2Th and DBF-2Th. Attaching bithiophene at both the 2 and 8 positions of dibenzothiophene and dibenzofuran, the extended conjugation of both electrochromic π-conjugated polymers showed good redox activity with two obvious redox peaks, high optical contrast (41% at 950 nm, PDBF-2Th), favorable response time (1.4 s for PDBT-2Th), decent coloration efficiency (359 cm2 C−1 at 547 nm, PDBF-2Th), and excellent kinetic stability (both remained 93% after 1000 s). [ABSTRACT FROM AUTHOR]

Electrochromic devices based on high-performance polymer materials with exceptional optical contrast, superior cycling stability, and large coloration efficiency are critical for the advancement of electrochromics, and have the potential to innovate a broad range of applications, including flexible displays and wearable electronics. Here, we design and synthesize three precursors of fluorobenzene-3-methylthiophene D-A-D type polymers through one-step Stille coupling, and then prepare the corresponding polymer films with good electrochemical and electrochromic properties via low-potential electropolymerization at 0.52 V vs Ag/AgCl. Interestingly, such polymers exhibit overall high electrochromic performances during the electrochemical reaction with inversible color changes between yellow and dark blue, including high optical contrast (83% at 1050 nm), fast response time (1.4 s / 0.8 s), and long-term stability (< 2% reduction after 250 cycles). As-fabricated electrochromic devices display excellent cycling stability (< 3% optical contrast degradation after 1,000 cycles) at a low drive voltage (0.8 V). Due to these excellent electrochromic properties, d -A-D type polymers based on fluorobenzene-3-methylthiophene can be further developed for practical applications such as near-infrared camouflage and E-displays. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract In recent years, polyselenophene and its derivatives have been paid more attention due to their unique properties such as lower band gaps and redox potentials. However, the poor solubility and molecular rigidity of polyselenophene and its derivatives limit them to use in flexible optoelectronic devices. Therefore, in order to enrich the structures and properties, fully understand the structure-property relationship and further improve the electrochromic performances of polyselenophene and its derivatives, we synthesized its propyl-analogues as precursors, to electrosynthesize three conducting polymers, poly(3,4‑propylenedioxyselenophene) (PProDOS) and its alkyl-modified derivatives, poly(3,3′‑dimethyl‑3,4‑dihydro‑2H‑selenopheno[3,4‑b][1,4]dioxepine) (PProDOS-C 1) and poly(3,3′‑dibutyl‑3,4‑dihydro‑2H‑selenopheno[3,4‑b][1,4]dioxepine) (PProDOS-C 4). The electrochemical and spectroelectrochemical behaviors of PProDOS and PProDOS-C n (n = 1, 4) were investigated in detail in an ionic liquid, 1‑butyl‑3‑methylimidazolium hexafluorophosphate (BmimPF 6). Results showed that PProDOS-C 1 and PProDOS-C 4 exhibited superior electrochromic performances such as high optical contrast (62%) and excellent coloration efficiency (573 cm2 C−1). In addition, as the alkyl chains increased, the onset oxidation potentials of monomers and the optical band gaps of polymer films decreased and the electrochemical activity of polymers increase. These polymers supply varied electrochromic colors and have prospect in display application. Graphical abstract Poly(3,4‑propylenedioxyselenophene) and its alkyl-modified derivatives films were facilely electrosynthesized in an ionic liquid, 1‑butyl‑3‑methylimidazolium hexafluorophosphate. The attached alkylic molecular structures improved electrochemical and electrochromic performances of alkyl-modified derivatives. Alkyl-modified derivatives of poly(3,4‑propylenedioxyselenophene) exhibit high transmittance changes (~62%) and coloration efficiency (~573 cm2 C−1) and reversible color changes from blue to light green. Unlabelled Image Highlights • The electrosynthesis electrochemical performances of three alkyl-modified poly(3,4-propylenedioxyselenophene)s were researched in BmimPF 6. • PProDOS-C 4 exhibited favorable stability (~87% after 5000 cycles) in BmimPF 6. • Alkyl-modified derivatives of PProDOS exhibited high optical contrast (62%), excellent coloration efficiency (573 cm2 C-1). [ABSTRACT FROM AUTHOR]

Graphical abstract A high-sensitive fluorescent sensor based on electrosynthesized poly(Fmoc- l -serine) enables ultra-trace analysis of Cr 2 O 7 2− in agro-product samples. Highlights • An electrosynthesized conjugated polymer PFOLS was first provided. • PFOLS has been used as a fluorescent probe for Cr 2 O 7 2− at ultra-trace levels. • Employing fluorescent conjugated polymer is a strategy designing high-sensitive sensors. Abstract A fluorescent sensor based on the electrosynthesized conjugated polymer poly(Fmoc- l -serine) (PFOLS) for highly sensitive analysis of Cr 2 O 7 2− at ultra-trace levels in water and agro-product samples was reported. PFOLS was obtained by potentiostatical electropolymerization of corresponding monomer Fmoc- l -serine in CH 2 Cl 2 -boron trifluoride diethyl etherate system. The introduction of serine group in PFOLS efficiently avoided the interference of anions and other acid substances in agro-products. Although metal ion Fe3+ could also quench the fluorescence of PFOLS , EDTA could recover the fluorescence of PFOLS -Fe3+ system. So in the presence of EDTA, PFOLS had a high-selectivity to Cr 2 O 7 2− and it could detect Cr 2 O 7 2− in linear ranges of 80 pM to 1.95 mM with a low detection limit of 72 pM. Then PFOLS was used to detect Cr 2 O 7 2− in water samples (tap water, lake water, and wastewater) and agro-product samples (white rice, red rice, and black rice) with satisfactory results, revealing that PFOLS could be as a practical sensing platform for ultra-trace analysis of Cr 2 O 7 2− in environment and agro-product samples. [ABSTRACT FROM AUTHOR]

The selenium analogue of 3,4-ethylenedioxythiophene (EDOT), 3,4-ethylenedioxyselenophene (EDOS), has been facilely electropolymerized with a low oxidation potential at 0.9 V to poly(3,4-ethylenedioxyselenophene) (PEDOS) films in microemulsion system with deionized water (DW) as solvent, sodium dodecyl benzene sulfonate (SDBS) as surfactant and LiClO 4 as supporting electrolyte. The effect of microemulsion on the structure, morphology, electrochemical, and optical properties as well as electrochromic performances of PEDOS films was investigated. PEDOS films displayed satisfactory electroactivity, eminent redox stability with compact morphology. PEDOS films prepared from aqueous microemulsion exhibited the electrochromic blue color conversion from deep (reduced) to light (oxidized), and had ordinary coloration efficiencies (24 cm 2 /C, 20 cm 2 /C, 19 cm 2 /C in microemulsion, BmimPF 6 and ACN, respectively), decent contrast ratios (25% in BmimPF 6 ), low switching voltages, and color persistence. [ABSTRACT FROM AUTHOR]

A dissolvable conjugated polymer oligo(1-pyreneboronic acid) (OPYBA) as the fluorescent sensor was facilely electrosynthesized for highly selective analysis of Cu 2+ at ultra-trace levels in real samples. OPYBA was obtained by potentiostatical electropolymerization of corresponding monomer at 1.0 V vs. Ag/AgCl in acetonitrile containing tetrabutylammonium tetrafluoroborate and dedoped with dilute HCl. The tetrahydrofuran-solvable OPYBA showed good fluorescent properties and could specifically recognize Cu 2+ , and then it was employed for the quantification of Cu 2+ in linear ranges of 25 pM–88.2 μM and 188 μM–750 μM with a low detection limit of 23 pM. As the fluorescent sensor, OPYBA displayed a high sensitivity and selectivity for Cu 2+ over other substances existing in environment and agro-products such as metal ions, anions, organic acids, amino acids, and carbohydrates. Also, it was used to detect Cu 2+ in tap water, lake water, white rice, Chinese cabbage, and cropland soil samples with satisfactory results, revealing that OPYBA could be as a practical sensing platform for ultra-trace analysis of Cu 2+ in environment and agro-product samples. [ABSTRACT FROM AUTHOR]

Poly(3,4-ethylenedioxyselenophene) (PEDOS) prepared via electropolymerization was investigated as an active electrode material for supercapacitor in 0.1 M CH 3 CN-LiClO 4 . Meanwhile, Poly(3,4-ethylenedioxythiophene) (PEDOT) as a contrast was prepared and measured under the same conditions. The resultant polymers were characterized by EQCM, FT-IR, SEM, CV and EIS. Although EDOS possessed higher molar mass which may result in lower specific capacitance in theory, but the higher doping level ( y = 0.53) make the specific capacitance of PEDOS over that of PEDOT. Based on this, PEDOS has the potential to become a good supercapacitor material. The compact PEDOS electrode afforded a higher specific capacitance of 208 F g −1 at 25 mV s −1 compared with PEDOT (205 F g −1 ). Furthermore, the specific capacitance of the symmetric full cell based on two PEDOS electrodes reached 42.02 F g −1 at 25 mV s −1 . [ABSTRACT FROM AUTHOR]

The derivative of terthiophene oligomer 2-(2,5-di(thiophen-2-yl)thiophen-3-yl)acetic acid (TTAA) was synthesized, and its electropolymerization was researched comparatively by using three systems (CH 3 CN-Bu 4 NPF 6 , CH 2 Cl 2 -Bu 4 NPF 6 , and BFEE). The effects of solvent on the electrochemical, morphology, redox stability, spectroelectrochemical properties and electrochromic performance of the achieved poly(2-(2,5-di(thiophen-2-yl)thiophen-3-yl)acetic acid) (PTTAA) films were studied in detail. PTTAA could be electrosynthesized in all the three systems facilely and displayed wonderful electroactivity and prominent redox stability in a wide potential window. The PTTAA films obtained in CH 3 CN-Bu 4 NPF 6 and CH 2 Cl 2 -Bu 4 NPF 6 had similar electrochemistry property except morphology. PTTAA formed in BFEE had lower oxidation potential (0.4 V) and better cycling stability. Also, it showed moderate response time (1.2 s) and excellent coloration efficiency (391 cm 2 C −1 ), enhanced its possible application as electrochromic material. So compared with common solvents CH 3 CN and CH 2 Cl 2 , TTAA could electrochemical polymerization at a lower potential and got higher quality polymer films in the strong Lewis acid BFEE. And this also made PTTAA as-formed in BFEE had better redox stability and electrochromic perfromance. [ABSTRACT FROM AUTHOR]

Relative to those polymers based on thiophene, the polymers derived from planar symmetrical thieno[3,2- b ]thiophene moieties exhibit highly ordered crystalline, fast charge transport behaviors and good stability. Herein, the effects of the polymerization solvent, potential, and temperature on the structure, morphology, thermal stability and capacitive performance of the electrodeposited poly(thieno[3,2 -b ]thiophene) (PTT) film were studied by FT-IR, SEM, TG and electrochemical methods, respectively. It was found that the PTT film had a very high specific capacitance (627.5 F g −1 at 15 A g −1 ) in acetonitrile/0.1 M LiClO 4 , even at high current density of 100 A g −1 , its specific capacitance still reached 531 F g −1 . Additionally, the morphology and capacitance performance of PTT film were greatly affected by the polymerization solvent, potential, and temperature parameters. Therefore, it is believed that PTT can be a meaningful capacitive material if only the preparation condition is well optimized. [ABSTRACT FROM AUTHOR]

A purple emitting monomer, namely 5-(benzo[ d ][1,3]dioxol-5-yl)-2,3-dihydrothieno[3,4- b ][1,4]dioxine (EDOT-MDOB) was synthesized via Stille coupling reaction and was characterized by FT-IR and NMR. The corresponding blue-light-emitting polymer poly(5-(benzo[ d ][1,3]dioxol-5-yl)-2,3-dihydrothieno[3,4- b ] [1,4]dioxine) P(EDOT-MDOB) was prepared with high redox activity and fluorescence quantum yields. Optical band gaps of P(MDOB-EDOT) were determined from the overall absorption and found as 1.59 eV. Smooth and homogeneous P(EDOT-MDOB) remained constant color of dark brown under different applied voltages. Electrochromic switching studies showed that P(EDOT-MDOB) exhibited moderate transmittance with good stability in the visible and near-IR region. [ABSTRACT FROM AUTHOR]

Two novel furan and pyridinechalcogenodiazole based monomers, namely 4,7-di(furan-2-yl)-[1, 2, 5]thiadiazolo[3,4- c]pyridine (Fu-S-Fu) and 4,7-di(furan-2-yl)-[1, 2, 5]selenadiazolo [3,4- c]pyridine (Fu-Se-Fu), where a single atom in the pyridinechalcogenodiazole unit is varied from S to Se, were designed and synthesized via a donor-acceptor approach, and then the corresponding polymers, P(Fu-S-Fu) and P(Fu-Se-Fu), were electrosynthesized. Also, structure characterization and optoelectronic properties, including FTIR, SEM, DFT theoretical calculations, intramolecular charge transfer nature, optical and electrochemical behaviors, and electrochromic performance, were systematically investigated and comparatively discussed. The obtained monomers exhibited lower oxidation potential (Fu-S-Fu: 1.12 V; Fu-Se-Fu: 1.09 V), leading to the facile electrodeposition of uniform hybrid polymer films with outstanding electroactivity at low oxidation potentials. Optical spectroscopy of corresponding polymers showed that Se substitution led to a red-shift in the low-energy transition, while the high-energy band remains relatively constant in energy. [ABSTRACT FROM AUTHOR]

π-Conjugated monomer, namely 2,8-bis-(4-octoxythiophen-2-yl)-dibenzothiophene (DBT-3OctTh), containing dibenzothiophene moiety as the central unit and 3-octoxythiophene as the external unit have been synthesized via Stille coupling reaction. The monomer was obtained as white powder in a yield of 75 %. Its electropolymerization was comparatively investigated in different media (dichloromethane (DCM), propylene carbonate (PC), or boron trifluoride diethyl etherate (BFEE)), all using BuNPF as the electrolyte. In BFEE, DBT-3OctTh revealed the lowest onset oxidation potential (0.67 V vs. Ag/AgCl) than DCM (1.12 V) and PC (1.13 V), leading to a facile electrodeposition to prepare poly(2,8-bis-(4-octoxythiophen-2-yl)-dibenzothiophene) (PDBT-3OctTh) with less possibility occurring on the side reactions. Doping level was calculated to be 0.32 in DCM, 0.12 in BFEE, and 0.04 in PC, respectively. The structure and performances of as-prepared polymers were systematically studied by cyclic voltammetry and spectroelectrochemistry. Spectroelectrochemical analysis revealed that PDBT-3OctTh films prepared in these media all switched light grey in the neutral state whereas blue in the oxidized state. Further, the existence of polaron or/and bipolaron in the oxidation process demonstrated that PDBT-3OctTh was p-dopable. [ABSTRACT FROM AUTHOR]

Poly(9,10-dihydrophenanthrene) (PDHP) and polyphenanthrene (PPhe) were synthesized electrochemically by direct anodic oxidation of their corresponding monomers in an ionic liquid BmimPF 6 . The electropolymerization performances of 9,10-dihydrophenanthrene (DHP) and phenanthrene (Phe), together with the properties of both polymers, including electrochemistry, optical properties, thermal degradation, and morphology were comparatively illustrated. FT-IR spectral analysis manifested that the polymerization of DHP occurred primarily at C(2) and C(7) positions, while Phe mainly through the coupling at C(9) and C(10) sites, in good agreement with previous results. Both PDHP ( E g = 2.55 eV) and PPhe ( E g = 2.18 eV) were electroactive and exhibited moderate redox stability, as well as good thermal stability. Furthermore, two polymers could emit yellow–green light, while PDHP showed higher fluorescence quantum yield of 0.14. [ABSTRACT FROM AUTHOR]

In this study, the electropolymerization of a novel methyl substituted unsymmetrical nitrogen analog of 3,4-ethylenedioxythiophene (EDOT), N-methyl-3,4-dihydrothieno[3,4-b][1,4]oxazine (MDTO) in air and moisture stable ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF 6 ) was reported. Electrochemical study demonstrated that MDTO exhibited a significantly lowered oxidation potential (0.51 V) and the resultant PMDTO films possessed favorable electroactivity and excellent electrochemical stability and could be further doped by cyclic voltammetry to substantially improve its doping level. The polymers also provided an optical band gap of about 1.6 eV, switching from slight blue in the oxidized form to dark blue in the reduced form with good optical contrast (24.0%), moderate response time (6.8 s) and excellent switching stability and color persistence ability. [ABSTRACT FROM AUTHOR]

Two novel EDOT end-capped monomers, namely, 2,8-di-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl-dibenzothiophene (DBT-EDOT), and 2,8-di-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl-dibenzofuran (DBF-EDOT), were synthesised via Stille coupling and electropolymerised to form conjugated polymers P(DBT-EDOT) and P(DBF-EDOT). The monomers exhibited blue-light-emitting characteristics, and DFT calculations revealed band gap values of 4.20 eV for DBT-EDOT and 4.34 eV for DBF-EDOT, while those of the corresponding polymers were brought down to 2.46 eV for P(DBT-EDOT) and 2.58 eV for P(DBF-EDOT), respectively. Moreover, both of the polymers displayed good electrochromic properties with colour switching between yellow in the reduced state and purple in the oxidised state. Structure characterisation and properties of monomers and as-formed polymers using FTIR spectroscopy, UV-vis spectroscopy, surface morphology, fluorescence spectroscopy, electrochemistry, and spectroelectrochemistry, together with structure–property relationships, were systematically investigated and comprehensively discussed. [ABSTRACT FROM AUTHOR]

Here, three new 3,4-ethylenedioxythiophene bis-substituted bithiophene containing alkyl side chain groups (alkyl = hexyl, octyl, and dodecyl) comonomers, 5,5′-(4,4′-dihexyl-[2,2′-bithiophene]-5,5′-diyl) bis(2,3-dihydrothieno[3,4-b][1,4]dioxine (BEDOT-BT-BH), 5,5′-(4,4′-dioctyl-[2,2′-bithiophene]-5,5′-diyl) bis(2,3-dihydrothieno[3,4-b][1,4]dioxine (BEDOT-BT-BO), and 5,5′-(4,4′-di dodecyl -[2,2′-bithiophene]-5,5′-diyl) bis(2,3-dihydrothieno[3,4-b][1,4]dioxine (BEDOT-BT-BD) were synthesized, and the three comonomers were facilely formed into PBEDOT-BT-BH, PBEDOT-BT-BO, and PBEDOT-BT-BD polymers on platinum electrode by direct anodic oxidation, respectively. The structure and morphology of the polymers were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and thermal analysis. Electrochemical performances of the polymers were also studied by galvanostatic charge–discharge, cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical results showed that three polymers showed good cycle ability and favorable capacitive performance, namely, for PBEDOT-BT-BH, PBEDOT-BT-BO, and PBEDOT-BT-BD, the specific capacitance was 132.5 F/g, 135.4 F/g, and 129.3 F/g (three electrode configurations) at 1 A/g, respectively, the capacitance retention was nearly 50.1%, 84.6% and 77.1% after 1000 cycles. The energy density of the symmetric full cell based on two PBEDOT-BT-BO electrodes was 9.5 Wh/kg −1 at a power density of 13.8 kW/kg −1 . These results implied that the three conducting polymers will be a kind of promising electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]

Novel solution-processable fluorescent oligo(1-aminopyrene) was readily electrosynthesized by direct anodic oxidation of its momomer 1-aminopyrene in neutral medium CH 2 Cl 2 –Bu 4 NPF 6 (0.1 mol L −1 ). FT-IR spectrum demonstrated that the polymerization of 1-aminopyrene probably occurred at C 3 and C 8 positions. In addition, the resulting oligo(1-aminopyrene) film showed good redox activity, water-solubility and enhanced fluorescence property in comparison with its monomer, indicating potential application as fluorescent materials. Oligo(1-aminopyrene) was also employed as fluorescent chemosensor to sense Fe(III) and Pd(II) in aqueous solution, and it showed pronounced sensitivity and fast response. [ABSTRACT FROM AUTHOR]

High polymerization degree is critical for polypyrene applying in fluorescent sensing field, which closely related to high sensitivity. However, polypyrene films reported are either insoluble and unprocessable or soluble with few repeat units. In this work, we synthesized a poly(1-pyrenebutyric acid) (PPBA) via electrochemical polymerization in boron fluoride ethyl ether system and the degree of polymerization was up to 43, which showed good fluorescence. The polymer showed high selectivity toward to Cr 2 O 7 2− among sixteen anions and twenty cations in ethyl alcohol system, and the limit of detection was as low as 1.58 fM. Transmission electron microscope results showed that the quenching mechanism of the PPBA was Cr 2 O 7 2−-induced inter- and intra-polymer aggregation of polymer chains in solution. Finally, PPBA was successfully applied in milk detection, implying that PPBA can realize the ultra-trace detection of Cr 2 O 7 2− in practical application. High degree of polymerization of poly(1-pyrenebutyric acid) fluorescence sensor that can specifically recognize Cr 2 O 7 2−. [Display omitted] • The fluorescence sensor PPBA with high polymerization degree was obtained by electropolymerization. • PPBA was highly sensitive to Cr 2 O 7 2− and the limit of detection was as low as 1.58 fM. • PPBA had a high anti-interference ability when sensing Cr 2 O 7 2−, avoiding the interference of common anions and cations. • PPBA was successfully used to detect Cr 2 O 7 2− in milk. [ABSTRACT FROM AUTHOR]

Highlights: [•] A novel 3,4-ethylenedioxythiophene bis-substituted bithiophene (BEDOT-BT) was synthesized. [•] BEDOT-BT was further electropolymerized into PEDOT-BT polymer. [•] PEDOT-BT had high thermal stability and electrochemical cycling stability. [•] The specific capacitance of PBEDOT-BT electrode reached 171 F g−1 at 1 A g−1. [ABSTRACT FROM AUTHOR]

Highlights: [•] C4-EDOT-COOH monomer with good solubility in water was synthesized by an efficient five-step route. [•] That acidic conditions were favorable for the electropolymerization of C4-EDOT-COOH. [•] The resulting high-quality polymer film can be employed for the fabrication of chemo/bio-sensors and optical sensors. [•] These as-prepared sensors can be applied to the simple, fast and sensitive detection of different analytes. [ABSTRACT FROM AUTHOR]

A simple and sensitive method is described for the electrochemical determination of shikonin, a widely used anti-tumoral agent, based on its electrochemical oxidation at a nanostructured poly(hydroxymethylated-3,4-ethylenedioxy-thiophene) (PEDOT-MeOH) electrode, which was fabricated by a facile electropolymerization method. Compared with bare and poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes, the PEDOT-MeOH film exhibited a distinctly higher activity for the electrooxidation of shikonin. The PEDOT-MeOH electrode showed a wide linear response for shikonin in the concentration range from 1.0 nM to 10.0 µM with detection limit of 0.3 nM. Furthermore, the PEDOT-MeOH electrode displayed high stability, good reproducibility and high sensitivity for the detection of shikonin. [ABSTRACT FROM AUTHOR]

Highlights: [•] Electropolymerization of 3,4-ethylenedithiathiophene in BmimPF6 was reported. [•] The structure and optoelectronic properties of PEDTT film were studied. [•] PEDTT could be redoped by cyclic voltammetry to improve its doping level. [•] PEDTT reveals favorable electrochromic properties. [Copyright &y& Elsevier]

Abstract: In this paper we describe the electropolymerization of 9-fluorenemethanol (FMO) in boron trifluoride diethyl etherate, which leads to low-potential electrodeposition of semiconducting poly(9-fluorenemethanol) (PFMO) film under optimized conditions. The as-formed PFMO film shows favorable solubility in common organic solvents, good redox activity and stability with a conductivity of 10−2 Scm−1, good thermal stability, and uniform morphology. Besides, PFMO exhibits electrochromic nature with its color changing from pale brown in its reduced form to dark blue upon oxidation, but its electrochromic performances are relatively poor. Fluorescence spectral studies demonstrated that soluble PFMO is highly fluorescent with its maximum emission at 418nm and a quantum yield of 0.52, and it can emit bright blue light under 365nm UV light irradiation. [Copyright &y& Elsevier]

Abstract: Water-soluble poly(9-aminofluorene) (P9AF) was facilely synthesized by the direct electropolymerization of commercially available monomer 9-aminofluorene in boron trifluoride diethyl etherate, and its preliminary application as a fluorescent chemosensor for the highly selective and sensitive detection of Fe(III) and inorganic phosphates (Pi) in an organic buffer 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (HEPES) (pH 7.0) was investigated. The one-step electrosynthesized P9AF with high quality and water-solubility possessed good fluorescence properties. P9AF was employed to sense Fe(III) in aqueous solution, displaying high selectivity, pronounced sensitivity, low detection limit, and fast response. On binding to Fe(III), exceptional fluorescence quenching of P9AF occurred, demonstrated by a >94% reduction in the fluorescence intensity. P9AF–Fe(III) complex exhibited high sensitivity and rapid response to Pi with turn-on fluorescence. The working mechanism was proposed and confirmed by transmission electron microscopy. The determination of Fe(III) in real samples and the interaction of P9AF with Fe(III) and Pi in living cells were investigated with satisfying results, showing that the cost-effective, water-soluble, and electrosynthesized P9AF has potential application in biological system and environment. [Copyright &y& Elsevier]

Abstract: The direct anodic oxidation electropolymerization of 3,4-ethylenedioxythiophene (EDOT) in IL microemulsions, BmimPF6/Tween 20/H2O, has been investigated for the first time. Electrochemical measurements indicated that among water-in-BmimPF6 (W/IL), bicontinuous (B.C.), and BmimPF6-in-water (IL/W) sub-regions in BmimPF6/Tween 20/H2O system, IL/W was the most suitable for the electropolymerization of EDOT, while the electropolymerization did not happen in W/IL. The use of IL microemulsions remarkably reduces the amount of IL, especially for IL/W. UV–vis spectra confirmed the formation of PEDOT. Scanning electron microscopy results demonstrated that nanostructures of compact PEDOT films were still obtained as in pure IL, implying their possible utilization in ion-selective electrodes, ion-sieving films, and matrices for hosting catalyst particles. [Copyright &y& Elsevier]

• Two donor-acceptor type pyrazine-EDOT hybrid polymers are electropolymerized and comparatively investigated. • High quality polymer films with excellent electrochemical stability are successfully obtained by low potential electropolymerization. • Pyrazine-EDOT hybrid polymer exhibits reversible color-changing nature from purple to gray with fast response time and high optical contrast in the NIR region. • Patterned flexible ECDs are fabricated by direct electropolymerization. • As-obtained ECDs display reversible color changes with decent optical stability and excellent mechanical stability. Two donor-acceptor type pyrazine-EDOT hybrid polymers are developed as high performance electrochromic materials and employed to fabricate flexible electrochromic devices via electropolymerization patterning. By coupling EDOT with pyrazine at 2,5-positions, the resultant precursor 2,5-BEP can facilely electropolymerize to yield high quality pyrazine-EDOT hybrid polymer films with excellent electrochemical stability. Spectroelectrochemistry and kinetic studies demonstrate that as-formed pyrazine-EDOT hybrid polymer exhibits reversible color-changing nature from purple to gray with high coloration efficiency (134 cm2 C−1), fast response time (0.2 s) and high optical contrast (> 55%) over a wide wavelength range of 800–2200 nm in near-infrared (NIR) region. To harness its excellent electrochromic performance as well as the ease of electropolymerization patterning, we fabricate patterned flexible electrochromic devices (ECDs) via facile electropolymerization and such ECDs display reversible color changes with decent optical stability (25% reduction in optical contrast upon 1000 cycling) and excellent mechanical stability (9.6% reduction in optical contrast upon bending 5000 cycles). The excellent electrochromic performance and stability of pyrazine-EDOT hybrid polymers as well as their-based ECDs make them good candidates towards near infrared electrochromic applications. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The porous structure produced by star -shaped molecules via electrochemical polymerization provides a number of transport channels, which will be beneficial for ions migration and improving electrochemical and electrochromic performance. Two novel star-shaped trithiophene and hexathiophene functionalized truxenes, Tr-3Th and Tr-6Th, were successfully synthesized. The corresponding porous polymers PTr-3Th and PTr-6Th, prepared by the electrochemical polymerization of the Tr-3Th and Tr-6Th, have provided compatible ion transport channels, which performed high electrochemical stability (maintain 99% electrochemical activity after 5000 cycles). PTr-3Th revealed colour change from light gray-green to dark gray-green upon oxidation, meanwhile, PTr-6Th presented the colour variations from light yellow to green. The result provides a new insight into the design of electrochromic polymers with good stability. Microporous polymers PTr-3Th and PTr-6Th, prepared by the electrochemical polymerization of monomers Tr-3Th and Tr-6Th, have provided compatible ion transport channels, which resulted into their high electrochemical stability (maintain 99% electrochemical activity after 5000 cycles). PTr-3Th revealed colour change from light gray-green to dark gray-green upon oxidation, meanwhile, PTr-6Th presented the colour variations from light yellow to green. Unlabelled Image • Two novel star-shaped trithiophene and hexathiophene functionalized truxenes, Tr-3Th and Tr-6Th were synthesized. • Porous PTr-3Th and PTr-6Th exhibited high electrochemical stability due to compatible ion transport channels. • PTr-6Th presented the obvious colour variations from light yellow to green. [ABSTRACT FROM AUTHOR]

The development of porous polymer films with high emission efficiency simultaneously overcomes the unprocessable and poor photofunctionality limitations faced in the conjugated porous polymers (CPPs) field, and therefore has attracted more and more attentions. In this work, monomer 1,1,2,2-tetrakis(4-(9H-carbazol-9-yl)phenyl)ethene that contained AIE-active tetraphenylethylene and carbazole units had been synthesized via McMurry reaction. And its corresponding CPP (PTCPE) films were easily obtained using the electropolymerization method in CH 2 Cl 2 -BFEE mixtures without adding any supporting electrolyte. These CPPs films exhibited high fluorescence in the solid state because of AIE-active TPE. Their electrochemical polymerization and fluorescence properties could be changed by adjusting the polymerization conditions. Image 1 • Highly luminescent photofunctional CPPs films were electrochemically prepared. • The electrochemical and fluorescence properties of polymer films can be adjusted by adjusting the BFEE content. • The high-throughput and facile electrochemical method can overcome the limitations faced in the CPPs field. [ABSTRACT FROM AUTHOR]

The introduction of fluorine into a compound or material is known to impart a range of interesting functionalities; however, the poor electrochemical capacity of existing fluorinated polymers limits their application in the field of energy storage. Thus, we herein report the successful preparation of several fluorinated polyindole materials exhibiting high energy storage behaviours using a simple electropolymerization strategy. Scanning and transmission electron microscopic images reveal that the monofluorinated polyindoles are mainly composed of one-dimensional (1D) nanofibers and nanorods, whereas 1D nanowires and two-dimensional (2D) nanosheets are obtained for the difluorinated polyindoles. Interestingly, the prepared fluorinated polyindoles are found to exhibit the highest specific capacitances among all reported fluorinated materials (i.e., 261–528 F g−1 at 18 A g−1). In addition, they exhibit a good cycle stability as well as a high rate capability. Our results indicate that fluorinated nano-polyindoles can be considered as promising electrode materials for energy storage applications. [ABSTRACT FROM AUTHOR]

Although much progress have been made on polyselenophenes-based molecular systems, the poor optoelectronic performance of parent polyselenophene still hamper both the fundamental understanding and practical applications of such materials due to the monomer instability during the polymerization process and the lack of suitable monomeric precursors. In this work, we develop an effective method to improve the optoelectronic performances and stability of parent polyselenophene by stepwise increasing the initial monomeric chain length for electrochemical polymerization. We find that the chain length increment of the monomeric structures from selenophene to bi- and tri-selenophenes dramatically reduces the electropolymerization potential and thus enables the formation of high quality polyselenophene films with better conjugated structures and less structural defects. As-formed polyselenophene from tri-selenophene reveals lowered optical band gap (1.72 eV), better redox activity and stability, and significantly improved electrochromic nature of reversible and stable color changes between red and blue with high performance including superior optical contrast up to 75%, high coloration efficiency up to 450 cm2 C−1, and very fast switching time (0.7 s for oxidation and 0.4 s for reduction). These advantageous properties of as-prepared polyselenophene films afford the successful fabrication of patterned flexible electrochromic devices, which exhibit reversible and stable color changes upon both doping-dedoping and mechanical bending. The chain length increment of the monomeric structures from selenophene to bi- and tri-selenophenes dramatically reduces their corresponding electrolysis potential and also structural defects of the resultant polyselenophene. Polyselenophene from bi- and tri-selenophene reveals superior optical contrast (60%), high coloration efficiency (224 cm2 C−1), and significantly improved redox stability. Flexible electrochromic devices display reversible and stable color changes upon long term bending. Image 1 • Stepwise enhancement from the chain length increment of varying selenophenes on the properties of polyselenophene. • Polyselenophene from bi- and tri-selenophene reveals superior electrochromic properties and redox stability. • Flexible electrochromic devices display reversible and stable color changes upon long term bending. [ABSTRACT FROM AUTHOR]