174508-31-7

Basic information

• Product Name: 5,7-Dibromo-2,3-dihydrothieno[3,4-b][1,4]dioxine
• Synonyms: 5,7-DIBROMO-2,3-DIHYDROTHIENO[3,4-B][1,4]DIOXINE;5,7-Dibromo-2,3-dihydrothieno[3,4-b][1,4]dioxine 97%;5,7-dibroMo-2H,3H-thieno[3,4-b][1,4]dioxine;2,3-Dihydro[2,5-dibroMothioeno] [3,4-b]-1,4-dioxin;2,5-Dibromo-3,4-ethylenedioxythiophene 97%;5,7-Dibromo-2,3-dihydrothieno[3,4-b][1,4]dioxine97%;4-b][1
• CAS NO: 174508-31-7
• Molecular Formula: C₆H₄Br₂O₂S
• Molecular Weight: 299.97
• Product Categories: Heterocyclic Compounds;Thiophens;Thiophen;Materials Science;New Products for Materials Research and Engineering;Organic and Printed Electronics;Synthetic Intermediates;Synthetic Tools and Reagents;Thiophene Monomers and Building Blocks
• Mol File: 174508-31-7.mol
• Article Data: 27

Chemical Properties

• Melting Point: 98 °C
• Boiling Point: 306.528 °C at 760 mmHg
• Flash Point: 139.184 °C
• Appearance: /
• Density: 2.14 g/cm³
• Vapor Pressure: 0.00139mmHg at 25°C
• Refractive Index: 1.644
• Storage Temp.: ?20°C
• Solubility: Chloroform (Slightly), Methanol (Slightly)
• CAS DataBase Reference: 5,7-Dibromo-2,3-dihydrothieno[3,4-b][1,4]dioxine(CAS DataBase Reference)
• NIST Chemistry Reference: 5,7-Dibromo-2,3-dihydrothieno[3,4-b][1,4]dioxine(174508-31-7)
• EPA Substance Registry System: 5,7-Dibromo-2,3-dihydrothieno[3,4-b][1,4]dioxine(174508-31-7)

Safety Data

• Hazard Codes: Xn
• Statements: 20/21/22-36/37/38-22
• Safety Statements: 22-26-36/37/39-24/25
• WGK Germany: 3
• Hazardous Substances Data: 174508-31-7(Hazardous Substances Data)

Usage

Chemical Properties

Needle-like solid

Uses

Different sources of media describe the Uses of 174508-31-7 differently. You can refer to the following data:
1. 5,7-Dibromo-2,3-dihydrothieno[3,4-b]-1,4-dioxine is used in the preparation of 3,4-ethylenedioxythiophene oligomers with optical and redox properties.
2. Used as a monomer in the synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) polymer which are used in electrochromic devices.

General Description

2,5-Dibromo-3,4-ethylenedioxythiophene (DBEDOT) is a monomer which is used in the synthesis of highly conducting poly(3,4-ethylenedioxythiophene) (PEDOT) polymer. This polymer is formed by solid-state polymerisation of DBEDOT and is used widely in organic-light emitting diodes and polymer field effect transistors. DBEDOT is a well-ordered crystalline monomer and produces PEDOT polymer which has a high degree of order.

InChI:InChI=1/C6H4Br2O2S/c7-5-3-4(6(8)11-5)10-2-1-9-3/h1-2H2

Upstream product

• 126213-50-1 3,4-(ethylenedioxy)thiophene 
• 154934-13-1 2,3-dihydro-thieno[3,4-b][1,4]dioxine-5,7-dicarboxylic acid diethyl ester 
• 18361-03-0 3,4-ethylenedioxythiophene-2,5-dicarboxyllic acid 

Downstream Products

• 291308-75-3 5-bromo-2-(mesitylthio)-3,4-ethylenedioxythiophene 
• 1086957-32-5 4-(5-(4-(dimethylamino)phenyl)-3,4-ethylenedioxythiophen-2-yl)benzenesulfonic acid 2,2-dimethylpropyl ester 
• 1086957-30-3 4-(5-bromo-3,4-ethylenedioxythiophen-2-yl)benzenesulfonic acid 2,2-dimethylpropyl ester 
• 1312573-37-7 5,7-bis(4-bromophenyl)-2,3-dihydrothieno-[3,4-b][1,4]dioxine 
• 1312573-38-8 2-(4-bromophenyl)-5-[4-(4-butylphenylamino)phenyl]-3,4-ethylenedioxythiophene 
• 1392224-24-6 5-chloro-3,4-ethylenedioxythiophene-2-carbaldehyde 
• 852054-42-3 7-bromo-2,3-dihydrothieno[3,4-b][1,4]dioxine-5-carbaldehyde 
• 1415917-07-5 C₂₆H₃₀O₆S 
• 1622008-73-4 2,5-bis(4,4’-bis(methoxyphenyl)aminophen-4’’-yl)-3,4-ethylenedioxythiophene 

Relevant articles and documents

Highly efficient, iodine-free dye-sensitized solar cells with solid-state synthesis of conducting polymers

A solid-state polymerizable conductive monomer with good conductivity and penetration to the photoelectrode is introduced to iodine-free, solid-state dye-sensitized solar cells (DSSCs) using an easily accessible and widely applicable fabrication method. A conducting polymer as a hole transporting material effectively penetrates into the TiO2 pores and polymerizes with heating to mild temperatures. The fabricated DSSCs exhibited the highest energy conversion efficiency of 5.4% in N719 dye.

Vortex fibril structure and chiroptical electrochromic effect of optically active poly(3,4-ethylenedioxythiophene) (PEDOT*) prepared by chiral transcription electrochemical polymerisation in cholesteric liquid crystal

Chiroptical electroactive poly(3,4-ethylenedioxythiophene) (PEDOT) was electrochemically synthesised in a cholesteric liquid crystal (CLC) electrolyte solution from the terEDOT monomer. PEDOT synthesised from terEDOT was found to enable the formation of a

Solid-State Synthesis of a Conducting Polythiophene via an Unprecedented Heterocyclic Coupling Reaction

Prolonged storage (～2 years) or gentle heating (50-80 °C) of crystalline 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) affords a highly conducting, bromine-doped poly(3,4-ethylenedioxythiophene) (PEDOT), as confirmed by solid-state NMR, FTIR, CV, and vis-NIR spectroscopies. The novel solid-state polymerization (SSP) does not occur for 2,5-dichloro-3,4-ethylenedioxythiophene (DCEDOT), and requires a much higher temperature (>130 °C) for 2,5-diiodo-3,4-ethylenedioxythiophene (DIEDOT). X-ray structural analysis of the above dihalothiophenes reveals short Hal...Hal distances between adjacent molecules in DBEDOT and DIEDOT, but not in DCEDOT. The polymerization may also occur in the melt but is significantly slower and leads to poorly conductive material. Detailed studies of the reaction were performed using ESR, DSC, microscopy, and gravimetric analyses. SSP starts on crystal defect sites; it is exothermic by 14 kcal/mol and requires activation energy of ～26 kcal/mol (for DBEDOT). The temperature dependence of the conductivity of SSP-PEDOT (σrt = 20-80 S/cm) reveals a slight thermal activation. It can be further increased by a factor of 2 by doping with iodine. Using this approach, thin films of PEDOT with conductivity as high as 20 S/cm were fabricated on insulating flexible plastic surfaces.

Synthesis and electrical properties of novel oligothiophenes partially containing 3,4-ethylenedioxythiophenes

Five sorts of soluble oligothiophenes (trimer to undecamer) containing 3,4-ethylenedioxythiophene (EDOT) were synthesized, and their optical and electrochemical properties were investigated in relation to the chain length of oligothiophenes and the number of EDOT units. The introduction of the EDOT unit into a main oligothienylene unit induced a red shift of absorption bands and a negative shift of oxidation potentials. The conductivity of an electrochemically oxidized film of undecamer was found to be around 1 S cm-1. A thin-film field effect transistor was preliminary fabricated with neutral undecamer films and the hole mobility was determined.

Fully undoped and soluble oligo(3,4-ethylenedioxythiophene)s: Spectroscopic study and electrochemical characterization

Fully undoped oligo(3,4-ethylenedioxythiophene)s have been synthesized from polycondensation of the corresponding dibromomonomer in the presence of a catalytic Ni(0)-based complex in N,N-dimethylacetamide (DMA). HPLC analysis indicated that the material is constituted of three main oligomers which have also been clearly detected by UV-Visible spectroscopy. Due to its partial solubility in DMA, processability is improved compared to the corresponding insoluble polymer and thin films of oligomers can be deposited by evaporation. Electrochemical and electrochromic properties of undoped film have been carried out. Deep purple in its undoped state, the material becomes sky blue in the oxidized form. The mixture of oligomers was characterized by means of Raman scattering, IR absorption and X-Ray dffraction (XRD), and compared to the poly(3,4-ethylenedioxythiophene) obtained by the oxidative route.

Direct C-H Arylation Polymerization to form Anionic Water-Soluble Poly(3,4-ethylenedioxythiophenes) with Higher Yields and Molecular Weights

A facile and environmentally benign Pd-catalyzed direct C-H arylation polymerization (DAP) has been developed for the syntheses of homo- and copolymers of anionic-group-functionalized 3,4-ethylenedioxythiophenes with high yields (up to 99%), high molecular weights, and narrow polydispersities. The effects of various Pd catalysts, phosphine ligands, and additives on the properties of the polymers have been examined. The method gives anionic poly(3,4-ethylenedioxythiophenes) with higher molecular weights than those produced by the previously reported chemical or electrochemical methods. The method was also used to synthesize polymers functionalized with carboxylic acid groups without the need for protection/deprotection steps. The resulting polymers can be processed from water or highly polar organic solvents. We also demonstrated a phosphine-free, water-mediated, Pd-catalyzed DAP. The anionic poly(3,4-ethylenedioxythiophenes) were stable in water, and are promising for applications in sensors, drug delivery, and cell engineering.

Significant Enhancement of the Electrical Conductivity of Conjugated Polymers by Post-Processing Side Chain Removal

The processability and electronic properties of conjugated polymers (CPs) have become increasingly important due to the potential of these materials in redox and solid-state devices for a broad range of applications. To solubilize CPs, side chains are needed, but such side chains reduce the relative fraction of electroactive material in the film, potentially obstructing π–π intermolecular interactions, localizing charge carriers, and compromising desirable optoelectronic properties. To reduce the deleterious effects of side chains, we demonstrate that post-processing side chain removal, exemplified here via ester hydrolysis, significantly increases the electrical conductivity of chemically doped CP films. Beginning with a model system consisting of an ester functionalized ProDOT copolymerized with a dimethylProDOT, we used a variety of methods to assess the changes in polymer film volume and morphology upon hydrolysis and resulting active material densification. Via a combination of electrochemistry, X-ray photoelectron spectroscopy, and charge transport models, we demonstrate that this increase in electrical conductivity is not due to an increase in degree of doping but an increase in charge carrier density and reduction in carrier localization that occurs due to side chain removal. With this improved understanding of side chain hydrolysis, we then apply this method to high-performance ProDOT-alt-EDOTx copolymers. After hydrolysis, these ProDOT-alt-EDOTx copolymers yield exceptional electrical conductivities (～700 S/cm), outperforming all previously reported oligoether-/glycol-based CP systems. Ultimately, this methodology advances the ability to solution process highly electrically conductive CP films.

Azatruxene-Based, Dumbbell-Shaped, Donor–π-Bridge–Donor Hole-Transporting Materials for Perovskite Solar Cells

Three novel donor–π-bridge–donor (D-π-D) hole-transporting materials (HTMs) featuring triazatruxene electron-donating units bridged by different 3,4-ethylenedioxythiophene (EDOT) π-conjugated linkers have been synthesized, characterized, and implemented in mesoporous perovskite solar cells (PSCs). The optoelectronic properties of the new dumbbell-shaped derivatives (DTTXs) are highly influenced by the chemical structure of the EDOT-based linker. Red-shifted absorption and emission and a stronger donor ability were observed in passing from DTTX-1 to DTTX-2 due to the extended π-conjugation. DTTX-3 featured an intramolecular charge transfer between the external triazatruxene units and the azomethine–EDOT central scaffold, resulting in a more pronounced redshift. The three new derivatives have been tested in combination with the state-of-the-art triple-cation perovskite [(FAPbI3)0.87(MAPbBr3)0.13]0.92[CsPbI3]0.08 in standard mesoporous PSCs. Remarkable power conversion efficiencies of 17.48 percent and 18.30 percent were measured for DTTX-1 and DTTX-2, respectively, close to that measured for the benchmarking HTM spiro-OMeTAD (18.92 percent), under 100 mA cm?2 AM 1.5G solar illumination. PSCs with DTTX-3 reached a PCE value of 12.68 percent, which is attributed to the poorer film formation in comparison to DTTX-1 and DTTX-2. These PCE values are in perfect agreement with the conductivity and hole mobility values determined for the new compounds and spiro-OMeTAD. Steady-state photoluminescence further confirmed the potential of DTTX-1 and DTTX-2 for hole-transport applications as an alternative to spiro-OMeTAD.