4,4'-Diiodobiphenyl
[CAS# 3001-15-8]

Identification

• Classification: Organic raw materials >> Hydrocarbon compounds and their derivatives >> Hydrocarbon halide
• Name: 4,4'-Diiodobiphenyl
• Synonyms: 1-iodo-4-(4-iodophenyl)benzene
• Molecular Formula: C₁₂H₈I₂
• Molecular Weight: 406.00
• CAS Registry Number: 3001-15-8
• EC Number: 221-080-5
• SMILES: C1=CC(=CC=C1C2=CC=C(C=C2)I)I

Properties

• Density: 2.0±0.1 g/cm³, Calc.^*
• Melting point: 201-204 °C (Expl.)
• Index of Refraction: 1.698, Calc.^*
• Boiling Point: 380.9±35.0 °C (760 mmHg), Calc.^*
• Flash Point: 191.5±21.4 °C, Calc.^*

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302+H312+H332
• Safety Statements: P261-P264-P270-P271-P280-P301+P317-P302+P352-P304+P340-P317-P321-P330-P362+P364-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H332
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315

• Transport Information: UN 3152

Discovery and Applications

4,4'-Diiodobiphenyl is an important organic compound with the chemical formula C12H8I2. It consists of a biphenyl backbone, where two phenyl groups (C6H5) are connected by a single carbon-carbon bond, with iodine atoms attached at the para positions (positions 4,4') of each ring. This compound has significant applications in organic electronics, materials science, and as a building block in the synthesis of other functional organic molecules.

The discovery of 4,4'-diiodobiphenyl can be traced to the mid-20th century, during a period of growing interest in halogenated organic compounds. Researchers were investigating the effects of halogen substitution on the electronic properties of aromatic compounds, and 4,4'-diiodobiphenyl emerged as a key example of how iodine atoms could influence molecular properties. The compound was synthesized through a variety of methods, including direct iodination of biphenyl using iodine in the presence of a catalyst or oxidizing agent.

One of the primary applications of 4,4'-diiodobiphenyl is in organic electronics, particularly in organic light-emitting diodes (OLEDs) and organic photovoltaic (OPV) devices. The iodine atoms on the biphenyl structure can help modify the electronic properties of the compound, making it a useful material for creating semiconducting layers in OLEDs. In OLEDs, the material is used as a dopant or a host in the emissive layer to enhance the performance of the device. Additionally, in OPV devices, 4,4'-diiodobiphenyl can be incorporated into the active layer to improve charge transport and increase the efficiency of light conversion.

Another important application of 4,4'-diiodobiphenyl is as a building block in the synthesis of other functional organic materials. It can be used in the creation of polycyclic aromatic compounds, which are of interest for their potential use in high-performance materials, including those for electronics and optoelectronics. The iodine atoms can be easily substituted with other functional groups, enabling the development of materials with tailored electronic, optical, and chemical properties. Moreover, 4,4'-diiodobiphenyl is also utilized in the synthesis of organic dyes and pigments, which are applied in various industries, including printing and textiles.

4,4'-Diiodobiphenyl also has applications in medicinal chemistry, where its halogenated biphenyl structure can serve as a precursor for the development of biologically active compounds. The iodine atoms can provide steric and electronic effects that influence the activity of the resulting compounds in various biochemical pathways.

In summary, 4,4'-diiodobiphenyl is a versatile chemical compound with broad applications in organic electronics, materials science, and medicinal chemistry. Its ability to modify the properties of organic materials makes it a valuable building block for the development of advanced technologies and functional compounds.

References

2024. Split cross-coupling via Rh-catalysed activation of unstrained aryl-aryl bonds. Nature Catalysis, 7(3).
DOI: 10.1038/s41929-024-01120-9

2015. Synthesis of substituted 4,4´-dihalobiphenyls and their use for the preparation of isomeric bis(carbazolyl)biphenyls. Russian Chemical Bulletin, 64(8).
DOI: 10.1007/s11172-015-1104-2

1974. Crystal and molecular structure of 4,4′-diiododiphenyl sulphone. Journal of Crystal and Molecular Structure, 4(5).
DOI: 10.1007/bf01636043