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Usage

Uses

Used in Organic Synthesis:
2H-Thieno[3,4-b][1,4]dioxepin, 3,3-bis(bromomethyl)-3,4-dihydrois used as a building block for the synthesis of other organic compounds. Its unique structure and bromomethyl groups make it a versatile intermediate for creating a variety of organic molecules.
Used in Medicinal Chemistry:
2H-Thieno[3,4-b][1,4]dioxepin, 3,3-bis(bromomethyl)-3,4-dihydrois used as a potential candidate in the development of pharmaceutical drugs. Its specific properties and potential uses would depend on further research and testing, but its presence in medicinal chemistry suggests it may have therapeutic applications or contribute to the development of new drugs.

Upstream product

• 51792-34-8 2,3-dimethoxythiophene 
• 3296-90-0 bis(bromomethyl)bis(hydroxymethyl)methane 

Downstream Products

• 634591-75-6 3,3-bis[[(2-ethylhexyl)oxy]methyl]-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin 

Relevant academic research and scientific papers

A side-chain defunctionalization approach yields a polymer electrochrome spray-processable from water

A π-conjugated electrochromic polymer (ECP) with alkyl ester side-chains is synthesized and subsequently defunctionalized to yield a polyionic salt readily soluble in water and further spray-processable from water. Upon neutralization, the defunctionalized polymer backbone recovers its electrochromic properties. The ability to print- or spray-process π-conjugated ECPs from aqueous media offers a sustainable alternative to traditional organic solvent-processing methods and could impact the development of non-emissive flexible display technologies. Copyright

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.

Yellow electrochromic polymer materials with fine tuning electrofluorescences by adjusting steric hindrance of side chains

A series of novel conducting conjugated yellow-to-transmissive electrochromic (EC) polymers were designed and synthesized to research their structure-property relationships, achieving electrofluorescent (EF) switching with applied external potential. These bifunctional materials are based on repeat units of bi-phenyl-1,3,4-oxadiazole and thiophene derivatives with different side chains. The polymers present a similar yellow color and emit various fluorescences with applied reduction potential, and they can turn to nearly transparent and non-fluorescent with oxidization potential. The optical contrast, electrochemical, electrochromic and electrofluorescent switching properties were also characterized in detail. A device containing these polymers was also fabricated that can achieve electrochromic and electrofluorescent switching simultaneously, making these polymers promising candidates for electro-bifunctional materials.

BLUE ELECTROCHROMIC COMPOUND, PREPARATION METHOD AND SUBASSEMBLY THEREOF

One class of blue thiophene electrochromic compounds include 3,4-(2,2-bis(2-oxo-3-phenylpropyl))propylenedioxythiophene, 3,4-(2,2-bis(2-oxo-3-phenylbutyl))propylenedioxythiophene, and 3,4-(2,2-bis(2-oxo-3-phenylamyl))propylenedioxythiophene. The thiophene electrochromic compounds can change color between blue and transparency. The thiophene compounds can be electropolymerized on the surface of the ITO glass to form a film. The film has characteristics of low driving voltage (within ±1V), fast response time, and large transmittance difference between colored-state and bleached-state (up to 77.5%). The thiophene electrochromic compounds can be used in the electrochromic window, rearview mirror, electrochomeric display, and the like.

Effects of Chemical Composition, Film Thickness, and Morphology on the Electrochromic Properties of Donor-Acceptor Conjugated Copolymers Based on Diketopyrrolopyrrole

A series of diketopyrrolopyrrole (DPP) and propylenedioxythiophene (ProDOT)-containing random copolymers with different donor-to-acceptor ratios is synthesized through Stille coupling polymerizations. The low-bandgap polymers display dark tones with colors ranging from magenta to blue, and reveal reversible colored-to-transmissive electrochromism in absorption/transmission-type devices with high optical contrasts (up to 48 and 77 in the visible and near-infrared regions, respectively), modest switching speeds (a few to tens of seconds) and coloration efficiencies (267-5742C-1), as well as good long-term ambient redox stabilities. The structure-performance relationship of the polymers, in particular, the role of donor-to-acceptor ratio, is investigated, and it is shown that an increase in the amount of acceptor in the polymers leads to slower oxidative but faster reductive switching, accompanied with enhancement of the redox stability. In addition, further study on the influence of film thickness and film morphology reveals that devices with higher optical contrasts are attainable from thicker polymer films at the expense of switching speeds; films with high uniformity and connectedness together with open, loose structures at submicron to micron scale are favorable for achieving good electrochromic performance. On and off: A series of electrochromic diketopyrrolopyrrole-based conjugated polymers are synthesized and characterized. Reversible colored-to-transmissive optical changes with high contrasts and ambient redox stabilities are observed (see figure). The influences of donor-to-acceptor ratio and film morphology on the electrochromic performance are addressed.

Reversible full-color generation with patterned yellow electrochromic polymers

A different light: The yellow electrochromic copolymer, propylenedioxythiophene phenylene P(ProDOT-Ph) is patterned by the micromolding in capillaries (MIMIC) process to fabricate line gratings. Under illumination by white light, colors are generated by diffraction and can be changed by applying an external voltage (see picture). The diffracted color is blue shifted by electrochemical doping, a process that is completely reversible. Copyright

Spray coatable electrochromic dioxythiophene polymers with high coloration efficiencies

Four new disubstituted propylenedioxythiophene polymers have been synthesized by Grignard metathesis on the 1-5 g scale. All polymers were found to be soluble in chloroform, methylene chloride, toluene, and tetrahydrofuran and were fully structurally characterized having GPC determined number-average molecular weights ranging from 33000 to 47000 g mol-1. Dilute polymer solutions in toluene exhibited strong red fluorescence with moderate quantum efficiencies from 0.38 to 0.50. Homogeneous thin films were formed by electropolymerization and spray casting polymer solutions onto ITO coated glass slides at thicknesses of ca. 150 nm. The films were electroactive, switching from a dark blue-purple to a transmissive sky blue upon p-doping, often with subsecond switching times, and high electrochromic contrast luminance changes (% ΔY) of 40-70%. These studies revealed that the branched derivatives, [poly(3,3-bis(2-ethylhexyl)-3,4-dihydro-2H-thieno[3,4-o] [1,4]dioxepine)] and [poly(6,8-dibromo-3,3-bis(2-ethylhexyloxymethyl)-3,4-dihydro-2H-thieno[3,4-b][1, 4]dioxepine)], gave an electrochemical response and associated color change over a much smaller voltage range in comparison to the linear chain substituted derivatives, [poly(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-o][1,4]dioxepine)] and [poly(3,3-bis(octadecyloxymethyl)-3,4-dihydro-2H-thieno[3,4-b] [1,4]dioxepine)]. Composite coloration efficiency values were found up to 1365 cm2/C; this was considerably larger than values obtained from previously studied alkylenedioxythiophene based polymers (～375 cm2/C).