Low potential electrosyntheses of free-standing polyfluorene films in boron trifluoride diethyl etherate

High quality free-standing polyfluorene (PFe) films were synthesized electrochemically by direct anodic oxidation of fluorene in pure boron trifluoride diethyl etherate (BFEE) on stainless steel sheet. The oxidation potential of fluorene in this medium was measured to be only 1.1 V versus SCE, which was much lower than that determined in acetonitrile + 0.1 mol L⁻¹ TBATFB. PFe films obtained from this medium showed good electrochemical behavior, good thermal stability with conductivity of 0.25 S cm⁻¹, indicating that BFEE is a better medium than acetonitrile for the electrosyntheses of PFe films. FTIR and ¹H NMR spectral investigations indicated that the polymerization of fluorene occurred mainly at 2, 7 position. As-formed PFe films can be partly dissolved in acetone, acetonitrile, tetrahydrofuran, etc.     

Electrosyntheses of free-standing poly(dibenzo-18-crown-6) films in boron trifluoride diethyl etherate on stainless steel electrode

High-quality free-standing poly(dibenzo-18-crown-6) (PDBC) films with a conductivity of 4.1 × 10⁻² S cm⁻¹ and good thermal stability were synthesized electrochemically on stainless steel electrode by direct anodic oxidation of dibenzo-18-crown-6 (DBC) in pure boron trifluoride diethyl etherate (BFEE). In this medium, the oxidation potential onset of DBC was measured to be only 0.98 V vs. SCE, which was much lower than that in acetonitrile + 0.1 mol L⁻¹ Bu₄NBF₄ (1.45 V vs. SCE). PDBC films obtained from this medium showed good redox activity and stability in BFEE. The structural characterization of PDBC was performed using UV-vis, FTIR spectroscopy. The results of quantum chemistry calculations of DBC monomer and FTIR spectroscopy of PDBC films indicated that the polymerization mainly occurred at C₍₄₎ and C₍₅₎ positions). Fluorescent spectral studies indicated that PDBC was a blue light emitter. To the best of our knowledge, this is the first report on the electrodeposition of free-standing PDBC films.     

Electrosyntheses and characterization of poly(9-bromophenanthrene) in boron trifluoride diethyl etherate

A novel semi-conducting polymer poly(9-bromophenanthrene) (P9BP) was synthesized electrochemically by direct anodic oxidation of it is monomer 9-bromophenanthrene (9BP) in boron trifluoride diethyl etherate (BFEE). The oxidation onset potential of 9BP in this medium was measured to be only 1.33 V vs. saturated calomel electrode (SCE). P9BP films obtained from BFEE showed good electrochemical behavior and nice thermal stability with electrical conductivity of 0.03 S cm⁻¹. FTIR and ¹H NMR spectra together with theoretical quantum chemistry calculations indicated that the P9BP was mainly grown via the coupling of the monomer at C₃ and C₆ positions. Furthermore, P9BP exhibited strong electrochromic nature from opaque green to light yellow between the doped and dedoped states on ITO electrode in solid state. Fluorescence spectral studies indicated that P9BP was a blue light emitter.     

Electrosyntheses of poly(2,3-benzofuran) films in boron trifluoride diethyl etherate containing poly(ethylene glycol) oligomers

Visible-light transparent high-quality substrate-supported poly(2,3-benzofuran) (PBF) film has been successfully electrosynthesized by direct anodic oxidation of 2,3-benzofuran on stainless steel sheet in boron trifluoride diethyl etherate (BFEE) containing 10% poly(ethylene glycol) (PEG) with molar mass of 400 (by volume). The oxidation potential of 2,3-benzofuran in this medium was measured to be only 1.0 V vs. SCE, which is lower than that determined in acetonitrile + 0.1 M Bu₄NBF₄ (1.2 V vs. SCE). The PBF films obtained in this media showed good electrochemical behaviors and good thermal stability with conductivity of 10⁻² S cm⁻¹, and the doping level of as-prepared PBF films was determined to be only 8.9%. The structure and morphology of the polymer were investigated by UV-vis, infrared spectroscopy and scanning electron microscopy (SEM), respectively. To the best of our knowledge, this is the first case for the syntheses of PBF films.     

Electrosyntheses of high‐quality poly(5‐nitroindole) films in boron trifluoride diethyl etherate containing additional diethyl ether

High‐quality poly(5‐nitroindole) (PNP) films were synthesized electrochemically by the direct anodic oxidation of 5‐nitroindole in boron trifluoride diethyl etherate (BFEE) containing additional 10% diethyl ether (EE) (by volume). The addition of EE to BFEE could improve the solubility of the monomer. The oxidation potential onset of 5‐nitroindole in this medium was measured to be only 1.04 V versus a saturated calomel electrode (SCE), which was much lower than that determined in acetonitrile and 0.1 mol L^?1 tetrabutylammonium tetrafluoroborate (1.53 V vs SCE). PNP films obtained from this medium showed good electrochemical behavior and good thermal stability with a conductivity of 10^?2 S cm^?1; this indicated that BFEE containing 10% EE was a suitable medium for the electrosyntheses of PNP films. Structural studies showed that the polymerization of the 5‐nitroindole ring occurred at the 2,3‐position. As‐formed PNP films were thoroughly soluble in the strong polar organic solvent dimethyl sulfoxide and partly soluble in tetrahydrofuran or acetone. Fluorescent spectral studies indicated that PNP was a good green‐light emitter, with excitation and emission wavelengths of 420 and 550 nm, respectively. To the best of our knowledge, this is the first time that nitro‐group‐substituted high‐quality conducting polymer films have been electrodeposited. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3986–3997, 2005     

Low potential electrosyntheses of free‐standing poly(dibenzofuran) films in mixed electrolytes of boron trifluoride diethyl etherate and trifluoroacetic acid

Free‐standing poly(dibenzofuran) (PDBF) films were synthesized electrochemically by direct anodic oxidation of dibenzofuran in mixed electrolytes of boron trifluoride diethyl etherate (BFEE) containing certain amount of trifluoroacetic acid (TFA). The oxidation potential of dibenzofuran in pure BFEE was measured to be only 1.31 V versus saturated calomel electrode (SCE). This value was much lower than that determined in acetonitrile + 0.1 mol L^?1 TBATFB (2.14 V vs. SCE). The addition of TFA to BFEE can further decrease the oxidation potential of the monomer to 1.07 V versus SCE in the mixed electrolyte of BFEE + 30% TFA. PDBF films obtained from this medium showed good electrochemical behavior, good electrochromic properties, and good thermal stability with conductivity of 10⁰ S cm^?1. FTIR and ¹H NMR spectra showed that the polymer was grown mainly via the coupling of the monomer at C₍₃₎ C₍₁₀₎ or C₍₄₎ C₍₉₎ positions (Scheme 1). As‐formed PDBF films were partly soluble in tetrahydrofuran (THF) or chloroform. Fluorescent spectral studies indicated that either soluble or PDBF in solid state was a good blue light PDBF emitter. To the best of our knowledge, this is the first report that free‐standing PDBF films can be electrodeposited. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1125–1135, 2006     

Electrosynthesis of highly conducting poly(1,5-dihydroxynaphthalene) in BF3·Et2O

Direct anodic oxidation of 1,5-dihydroxynaphthalene (DHN), an important derivative of naphthalene, led to the formation of high-quality semiconducting poly(1,5-dihydroxynaphthalene) (PDHN) on stainless steel sheets in boron trifluoride diethyl etherate (BFEE). The onset oxidation potential of DHN in this medium was measured to be only 0.78 V vs. SCE, which was lower than that determined in traditional acetonitrile containing 0.1 mol/L tetrabutylammonium tetrafluoroborate (0.98 V vs. SCE). As-formed PDHN films showed good redox activity and stability, together with interesting electrochromic property from brown (doped) to yellow-green (dedoped). Structural characterization, including FTIR, ¹H NMR, and quantum chemistry calculations, indicated that the polymerization of DHN probably occurred at C₄ and C₈ positions. Moreover, thermal analysis revealed that PDHN displayed better thermal stability than that synthesized by chemical method. The fluorescence spectral studies, together with the electrical tests, showed that PDHN was a good blue light-emitter (fluorescence quantum yield higher than 0.1) with an electrical conductivity of as high as 0.46 S/cm.     

Low potential electrochemical polymerization of diphenyl ether and characterization of its polymers

High‐quality poly(diphenyl ether) (PDPE) films with electrical conductivity of 4.4 × 10^?1 S cm^?1 were synthesized electrochemically by direct anodic oxidation of diphenyl ether (DPE) in boron trifluoride diethyl etherate (BFEE) containing 5% concentrated sulfuric acid (SA) (by volume). The oxidation potential onset of DPE in pure BFEE was measured to be only 1.37 V versus a saturated calomel electrode (SCE), which was much lower than that determined in acetonitrile + 0.1 mol L^?1 tetrabutylammonium tetrafluoroborate (1.98 V vs. SCE). The addition of SA to BFEE can further decrease the oxidation potential onset of the monomer to 1.18 V versus SCE in the mixed electrolyte of BFEE + 5% SA. PDPE films obtained from this medium showed good redox activity and stability even in concentrated SA. Dedoped PDPE films were partly soluble in the strong polar organic solvent dimethyl sulfoxide. Fluorescent spectral studies indicated that soluble PDPE was a good blue‐light emitter with a quantum yield of 0.30. Infrared spectroscopy and quantum chemistry calculations indicated that the electropolymerization of DPE occurred mainly at C₄ and C_4′. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5932–5941, 2007     

Direct electrosynthesis and characterization of a new soluble polyfluorene derivative containing carboxyl group in boron trifluoride diethyl etherate

High-quality poly(fluorene-9-acetic acid) (PFAA), a new soluble polyfluorene derivative, was synthesized electrochemically by direct anodic oxidation of fluorene-9-acetic acid (FAA) in boron trifluoride diethyl etherate (BFEE) containing a certain amount of trifluoroacetic acid (TFA). This electrolyte enables facile anodic oxidation of FAA monomer at lower potential (1.05 V vs. SCE). PFAA films with conductivity of 0.53 S cm⁻¹ obtained from this medium showed better redox activity and thermal stability in relation to unsoluble poly(fluorene-9-carboxylic acid). Fluorescent spectral studies indicate that PFAA film with high fluorescence quantum yields and photochemical stability is a good blue-light emitter. The structure and morphology of the polymer were studied by UV–vis, FT-IR, ¹H NMR spectra and scanning electron microscopy, respectively.     

Low-potential facile electrosyntheses of free-standing poly(5-methoxyindole) film with good fluorescence properties

High-quality free-standing poly(5-methoxyindole) (P5MIn) films were synthesized electrochemically by direct anodic oxidation of 5-methoxyindole (5MIn) in boron trifluoride diethyl etherate (BFEE). P5MIn films obtained from this medium showed good electrochemical behavior and good thermal stability with a conductivity of 0.12 S cm⁻¹. P5MIn films were insoluble in water, acetone and tetrahydrofuran. The structure of the polymer was studied by UV–visible spectroscopy and FT-IR spectroscopy, which indicated that the polymerization occurred at C₍₂₎ and C₍₃₎ position. Fluorescent spectral studies indicate that solid P5MIn film is a good blue emitter. Thermal stability of P5MIn film is higher than poly(5-methylindole) and poly(5-chloroindole) obtained from BFEE. To the best of our knowledge, this is the first report on the electrosyntheses of free-standing P5MIn films.     

Electrosyntheses of high‐quality polyphenanthrene in the electrolyte of boron trifluoride diethyl etherate containing trifluoroacetic acid

A novel inherently conducting polymer, high‐quality polyphenanthrene (PPh) films were synthesized electrochemically by direct anodic oxidation of phenanthrene (Ph) in boron trifluoride diethyl etherate (BFEE) containing a certain amount of trifluoroacetic acid (TFA). The oxidation potential of Ph in this medium was measured to be only 0.63 V versus SCE, which was greatly lower than that determined in acetonitrile + 0.1 mol L^?1 Bu₄NBF₄ (1.55 V vs. SCE). The electrolytes of BFEE containing TFA enable facile anodic oxidation of Ph monomer; however, similar oxidation using acetonitrile never produces such a polymeric material. PPh films obtained from this medium showed good redox activity and stability even in concentrated sulfuric acid. Dedoped PPh films were partly soluble in polar solvent such as CH₂Cl₂, acetone, tetrahydrofuran, and dimethyl sulfoxide. Fluorescent spectral studies indicate that PPh is a good blue‐light emitter. The structure and morphology of the polymer were studied by UV–vis spectroscopy, FTIR spectroscopy, ¹H NMR spectroscopy, and scanning electron microscopy, respectively. The results of quantum chemistry calculations of Ph monomer and the spectroscopies of dedoped PPh indicated the polymerization mainly occurred at C₍₉₎ and C₍₁₀₎ positions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3929–3940, 2007     

Electrosyntheses of freestanding polyindole films in boron trifluoride diethyl etherate

High‐quality freestanding polyindole (PIn) films were synthesized electrochemically through the direct oxidation of indole in pure boron trifluoride diethyl etherate (BFEE). The oxidation potential of indole in this medium was measured to be only 0.86 V versus a saturated calomel electrode, which was lower than that determined in acetonitrile/0.1 mol L^?1 Bu₄NBF₄. PIn films obtained from this medium showed better electrochemical behavior and better thermal stability with a conductivity of 10^?1 S cm^?1, and this indicated that BFEE was a better medium than acetonitrile for the electrosyntheses of PIn films. Structural studies showed that the polymerization of indole ring occurred at the 2,3‐position. As‐formed PIn films could be partly dissolved in acetone, acetonitrile, tetrahydrofuran, and so forth. Fluorescent spectral studies indicated that PIn was a good blue‐light emitter. To the best of our knowledge, this is the first report on the fluorescence of PIn. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1444–1453, 2005     

Electrosyntheses of freestanding poly (3-(4-fluorophenyl)thiophene) films in boron trifluoride diethyl etherate

High quality free-standing poly (3-(4-fluorophenyl)thiophene) (PFPT) films with conductivity of 10⁻¹ S/cm were electrosynthesized in boron trifluoride diethyl etherate (BFEE) by direct anodic oxidation of the monomer 3-(4-fluorophenyl)thiophene (FPT) on stainless steel sheet. As-formed flexible and shiny PFPT films can be cut into various shapes by a knife or a pair of scissors. The structure, thermal stability and morphology of PFPT films were studied by FT-infrared, UV-vis, Raman spectroscopy thermogravimetric analysis and scanning electron microscopy, respectively.     

Electrosyntheses and characterization of polyalkylenedioxybenzenes

Direct anodic oxidation of 1,2-methylenedioxybenzene (MDOB) and 1,2-ethylenedioxybenzene (EDOB), analogues of 3,4-alkylenedioxythiophene and 3,4-alkylenedioxypyrrole, led to the formation of polyacetylene derivatives, poly(1,2-methylenedioxybenzene) (PMDOB) and poly(1,2-ethylenedioxybenzene) (PEDOB), on a platinum sheet in pure boron trifluoride diethyl etherate (BFEE). IR, ¹H NMR, ¹³C NMR and quantum chemistry calculations confirmed that the polymerization occurred at C(4) and C(5) position on the benzene ring of the monomer, making the main backbone of PMDOB and PEDOB similar to polyacetylene. Both dedoped PMDOB and PEDOB in DMSO solution showed good fluorescence properties with quantum yields of 0.13 and 0.27, emitting blue and green light under excitation of 365 nm, respectively. PMDOB showed electrochromic properties from grass green (doped) to light nacarat (dedoped). PEDOB changed it from bottle green (doped) to nacarat (dedoped). Doped PMDOB and PEDOB own electrical conductivities of 0.1 S cm⁻¹ and 0.17 S cm⁻¹, respectively.     

三氟化硼乙醚溶液中聚(二苯并呋喃)的电化学合成

在三氟化硼乙醚-硫酸混合电解质溶液中,二苯并呋喃直接阳极氧化聚合可以获得高质量聚(二苯并呋喃)膜.二苯并呋喃在纯三氟化硼乙醚中的起始氧化电位为1.30 VvsSCE,远低于单体在0.1 mol.L-1Bu4NBF4乙腈溶液中的起始氧化电位(2.14 V).硫酸的加入进一步降低了二苯并呋喃的氧化电位.在三氟化硼乙醚-硫酸混合电解质溶液中,二苯并呋喃的起始氧化电位可降低至1.0 V;同时在该体系中获得的聚(二苯并呋喃)膜具有良好的电化学性质和荧光性质.     

四氢呋喃/三氟化硼乙醚混合电解质中咔唑的电化学聚合

在四氢呋喃/三氟化硼乙醚混合电解质中直接阳极氧化咔唑制备聚咔唑.单体的起始氧化电位为0.92 Vversus SCE,远低于单体在含0.1 mol.L-1Bu4NBF4的乙腈溶液中的起始氧化电位(1.36 Vversus SCE).在此体系中获得的聚咔唑膜具有良好的电化学活性和稳定性,其电导率为7.0×10-3S.cm-1.聚合物可部分溶解于二甲基亚砜等强极性有机溶剂.UV-Vis,FT-IR,1H-NMR证明聚合物共轭长链的形成.该体系中获得的聚咔唑是一种蓝光发射材料,并具有良好的热稳定性.     

三氟化硼乙醚中聚(N-甲基吲哚)的电化学合成

在三氟化硼乙醚(BFEE)溶液中N甲基吲哚可以阳极氧化聚合生成聚(N-甲基吲哚).单体在BFEE中的起始氧化电位为0.95V,远低于单体在CH3CN+0.1mol LBu4NBF4体系中的起始氧化电位(1.23V).BFEE中获得的聚(N-甲基吲哚)膜具有良好的电化学性质和荧光性质.红外光谱表明聚合反应发生在2,3位.     

9,10-二氢化菲在三氟化硼乙醚-浓硫酸混酸中的电化学聚合

在三氟化硼乙醚(BFEE)-浓硫酸混合电解质体系中直接氧化9,10-二氢化菲获得了高质量聚(9,10-二氢化菲)膜, 其电导率为3.8×10－1 S/cm. 9,10-二氢化菲在BFEE＋10%浓硫酸体系中的起始氧化电位为0.93 V vs. SCE, 远低于其在乙腈＋0.1 mol/L Bu4NBF4溶液中的起始氧化电位(1.75 V vs. SCE). 在BFEE＋10%浓硫酸体系中获得的聚(9,10-二氢化菲)膜具有良好的电化学性质. 聚合物部分溶于二甲基亚砜、四氢呋喃、氯仿等极性溶剂. FT-IR和量化计算表明聚合反应主要发生在2, 7位或者3, 6位. 荧光光谱和热重分析表明聚合物是一种良好的蓝色荧光材料且具有良好的热稳定性.     

Electrosynthesis of blue-light-emitting oligo(1-bromopyrene) with favorable solubility

Bromo-group-substituted oligopyrene films were electrochemically synthesized by direct anodic oxidation of 1-bromopyrene (BrP) in boron trifluoride diethyl etherate (BFEE). The oxidation potential of BrP was measured to be approximately 0.52 V (vs. Ag/AgCl), which was much lower than that detected in a neutral electrolyte such as acetonitrile (1.2 V vs. Ag/AgCl) and CH₂Cl₂ (1.25 V vs. Ag/AgCl). Oligo(1-bromopyrene) (OBrP) films showed good redox activity in both BFEE and concentrated sulfuric acid. Fourier transform infrared spectroscopy, ¹H NMR, and theoretical calculations showed that the electropolymerization of the BrP monomer mainly occurred at the C₍₃₎, C₍₆₎, and C₍₈₎ positions. As-formed OBrP was a typical blue light emitter with fluorescent quantum yields of 0.27, also emitted strong and bright blue photoluminescence at excitation of 365 nm UV light. Furthermore, the films were readily soluble in dimethyl sulfoxide, CH₂Cl₂, acetonitrile, and acetone. All these results indicate that the striking OBrP films have many potential applications in various fields, such as optoelectronic materials, DNA fluorescence probes, and electrochemical sensors.     

Highly sensitive spectrofluorimetric kinetic determination of ultratrace amounts of vanadium(V) based on the oxidation of 1,8-diaminonaphthalene by bromate

A highly sensitive catalytic quenching spectrofluorimetric method was described for the determination of V(V) based on its catalytic effect on the oxidation of 1,8-diaminonaphthalene by potassium bromate with Tiron as an activator in weakly acidic medium and the reaction mechanism was investigated. The reaction was followed spectrofluorimetrically by measuring the fluorescence intensity of 1,8-diaminonathphlene (DAN) (λ_ex=356 nm, λ_em=439 nm) at a fixed time of 5 min from initiation of the reaction. Under the optimum conditions, vanadium(V) can be determined in the range 0.05-50.0 ng ml⁻¹ with a S.D.=0.024 for 15 times measurements. The detection limit of the method was down to 0.0088 ng ml⁻¹ and the catalytic reaction activation energy was found to be 43.92 kJ mol⁻¹. The proposed method was tested for the determination of vanadium(V) in rice and natural water samples.