2,5-Dibromothiophene
[CAS# 3141-27-3]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Thiophene compound
• Name: 2,5-Dibromothiophene
• Molecular Formula: C₄H₂Br₂S
• Molecular Weight: 241.93
• CAS Registry Number: 3141-27-3
• EC Number: 221-547-3
• SMILES: C1=C(SC(=C1)Br)Br

Properties

• Water solubility: practically insoluble
• Density: 2.2±0.1 g/cm³, Calc.^*, 2.147 g/mL (Expl.)
• Melting point: -6 °C (Expl.)
• Index of Refraction: 1.638, Calc.^*, 1.629 (Expl.)
• Boiling Point: 209.5±20.0 °C (760 mmHg), Calc.^*, 211 °C (Expl.)
• Flash Point: 99.4±0.0 °C, Calc.^*, 99 °C (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS06;GHS07;GHS08 Danger
• Risk Statements: H300-H315-H317-H319-H335-H341
• Safety Statements: P203-P261-P264-P264+P265-P270-P271-P272-P280-P301+P316-P302+P352-P304+P340-P305+P351+P338-P318-P319-P321-P330-P332+P317-P333+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin sensitization	Skin Sens.	1	H317
Acute toxicity	Acute Tox.	2	H300
Germ cell mutagenicity	Muta.	2	H341
Acute toxicity	Acute Tox.	3	H301
Eye irritation	Eye Irrit.	2A	H319
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H332

Discovery and Applications

2,5-Dibromothiophene is an organic compound that consists of a thiophene ring, a sulfur-containing five-membered heterocycle, with bromine atoms attached to the 2 and 5 positions. Its chemical formula is C4H2Br2S, and it is classified as a halogenated thiophene derivative. The compound appears as a yellow to light brown crystalline solid and is primarily used in organic synthesis, particularly in the preparation of materials with semiconducting properties.

The discovery of 2,5-dibromothiophene can be traced to the development of halogenated thiophenes as versatile building blocks in organic chemistry. Thiophene, first discovered in the 19th century, has since become a key heterocyclic compound due to its aromaticity and ability to participate in various reactions, such as electrophilic substitution. The addition of halogens like bromine to the thiophene ring enhances its reactivity and opens up new pathways for functionalizing organic materials, making it valuable in diverse applications.

2,5-Dibromothiophene has several significant applications, particularly in the field of organic electronics. It is commonly used in the synthesis of organic semiconductors, which are materials that can conduct electricity and are employed in the production of organic light-emitting diodes (OLEDs), organic photovoltaic cells (OPVs), and organic field-effect transistors (OFETs). The bromine atoms in 2,5-dibromothiophene play an essential role in enhancing the solubility and stability of the resulting materials, which is crucial for their performance in electronic devices.

One of the most notable applications of 2,5-dibromothiophene is in the preparation of conjugated polymers. These polymers are used in a variety of electronic and optoelectronic devices, where their conductivity and optical properties are tailored by altering the monomers from which they are derived. 2,5-Dibromothiophene serves as a key monomer for the synthesis of poly(thiophene) derivatives, which have been widely used in the development of flexible electronics, solar cells, and sensors.

In addition to electronics, 2,5-dibromothiophene is also utilized in the synthesis of other functionalized organic compounds. For example, it is used in the preparation of certain dyes, pigments, and intermediates in the production of pharmaceuticals. Its reactivity makes it an important precursor in the design of new materials with specialized properties for applications in various chemical and industrial sectors.

The compound’s role as a building block in organic synthesis, particularly for materials used in electronics, continues to drive research into its applications. Ongoing studies focus on improving the efficiency and stability of devices made from 2,5-dibromothiophene derivatives, with the aim of enhancing the performance of organic electronics in commercial applications.

References

2020. Trapping of Transient Thienyllithiums Generated by Deprotonation of 2,3- or 2,5-Dibromothiophene in a Flow Microreactor. Synlett, 31(18).
DOI: 10.1055/s-0040-1706479

2018. Classes of CPs: Part 2. Conducting Polymers, Fundamentals and Applications.
DOI: 10.1007/978-3-319-69378-1_35

2016. A novel double-layer electrospun nanofibrous membrane sensor for detecting nitroaromatic compounds. Journal of Materials Science, 51(19).
DOI: 10.1007/s10853-016-0252-6