3,4-(2,2-Dimethylpropylenedioxy)thiophene, also known as ProDOT-Me2 (CAS 255901-50-9), is a thiophene building block related to EDOT. In place of the ethylene bridge found in EDOT, it carries a dimethylpropylene group, a change that gives its polymer lower oxidation potentials and better stability than polythiophene. It is supplied at >97% purity (1H NMR in CDCl3) as a pale green to off-white powder or crystals.
The monomer is made by trans-etherification, refluxing 3,4-dimethoxythiophene with 2,2-dimethylpropane-1,3-diol in toluene with p-toluenesulfonic acid as catalyst. Its polymer, PProDOT-Me2, is a cathodic electrochromic material known for fast switching. An electrochromic window built on this polymer switched between coloured and bleached states in almost 0.7 s over +1.5 V to -1.5 V.
In a device using PProDOT-Me2 as the working electrode, bare indium tin oxide as counter electrode and AgNO3, LiBr/Br2 electrolyte, operation over 10,000 cycles was reported with a maximum optical modulation of 75.7% and a response time of about 5 s. Transparent, blue and opaque states were obtained by varying the applied voltage.
- Monomer for preparing the cathodic electrochromic polymer PProDOT-Me2.
- Fabrication of fast-switching electrochromic windows and devices.
- Building block for the synthesis of OLED materials.
- Intermediate for organic photovoltaic and low band gap polymer research.
- Synthesis of semiconductor materials for OFETs.
| Brand | Ossila |
|---|---|
| CAS number | 255901-50-9 |
| Molecular formula | C9H12O2S |
| Purity | >97% (1H NMR in CDCl3) |
| Category | — |
| Pack sizes | 1 g, 5 g, 10 g |
| Physical form | Pale green/off-white powder/crystals |
| Storage | — |
- Product code: B1041
- Molecular Weight: 184.26 g/mol
- Synonyms: 3,4-Dihydro-3,3-dimethyl-2H-thieno[3,4-b-1,4]dioxepine, ProDOT-Me2
- Melting Point: 45.0 °C
- Classification / Family: Thiophenes, semiconductor synthesis intermediates, low band gap polymers, OLED, OFETs, organic photovoltaics
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