Chloranil
[CAS# 118-75-2]

Identification

• Classification: Organic raw materials >> Quinones
• Name: Chloranil
• Synonyms: Tetrachloro-p-benzoquinone; 2,3,5,6-tetrachloro-1,4-benzoquinone; 2,3,5,6-tetrachloro-2,5-cyclohexadiene-1,4-dione; 2,3,5,6-Tetrachloro-p-benzoquinone; 2,3,5,6-Tetrachloroquinone; p-chloranil
• Molecular Formula: C₆Cl₄O₂
• Molecular Weight: 245.88
• CAS Registry Number: 118-75-2
• EC Number: 204-274-4
• SMILES: C1(=C(C(=O)C(=C(C1=O)Cl)Cl)Cl)Cl

Properties

• Density: 1.97 g/mL
• Melting point: 289 ºC
• Water solubility: insoluble

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Hazard Statements: H315-H317-H319-H332-H400-H410
• Precautionary Statements: P261-P264-P264+P265-P271-P272-P273-P280-P302+P352-P304+P340-P305+P351+P338-P317-P321-P332+P317-P333+P317-P337+P317-P362+P364-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Eye irritation	Eye Irrit.	2	H319
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Skin sensitization	Skin Sens.	1	H317
Acute toxicity	Acute Tox.	4	H332
Serious eye damage	Eye Dam.	1	H318
Eye irritation	Eye Irrit.	2A	H319

• Transport Information: UN 3077

Discovory and Applicatios

Chloranil, also known as 2,3,5,6-tetrachloro-1,4-benzoquinone, is a synthetic organic compound that plays a significant role in various fields, including organic chemistry and material science. It is a highly chlorinated derivative of quinone and is recognized for its distinctive yellow color and unique chemical properties, making it valuable in multiple applications.

The discovery of chloranil dates back to the early 20th century, around the 1930s, when it was synthesized through the chlorination of 1,4-benzoquinone. Researchers were investigating methods to produce more stable and reactive derivatives of quinones for use in dyes and pigments. The synthesis of chloranil involved the controlled reaction of benzoquinone with chlorine gas, resulting in a compound that exhibited enhanced stability and reactivity compared to its non-chlorinated counterparts.

Chloranil has garnered attention for its applications as a reagent and intermediate in organic synthesis. Its reactivity is primarily attributed to its ability to undergo redox reactions, enabling it to act as an electron acceptor in various chemical transformations. Chloranil is particularly useful in the synthesis of dyes, where it serves as a coupling agent and chromophore. The compound's vibrant color and stability make it an ideal candidate for producing colored materials, such as textiles and plastics.

In addition to its role in dye chemistry, chloranil is employed in analytical chemistry as a reagent for the detection of certain organic compounds. It can facilitate the identification of primary and secondary amines through the formation of colored complexes, aiding in the qualitative analysis of samples.

Furthermore, chloranil has been explored for its potential applications in the field of electronics. Its semiconductor properties have made it a candidate for use in organic electronic devices, such as organic solar cells and organic light-emitting diodes (OLEDs). Research into the electronic properties of chloranil continues to reveal new possibilities for its integration into advanced materials and technologies.

Despite its usefulness, chloranil must be handled with caution due to its toxicity and potential environmental impact. Research is ongoing to better understand its safety profile and to explore safer alternatives in its applications.

In summary, chloranil is a versatile compound with a rich history in organic synthesis and material science. Its unique properties and reactivity have led to its application in dyes, analytical chemistry, and electronics, highlighting its significance in both scientific research and industrial applications.

References

2019. An unusual double radical homolysis mechanism for the unexpected activation of aldoxime nerve-agent antidotes by polyhalogenated quinoid carcinogens under normal physiological conditions. Free Radical Biology and Medicine.
DOI: 10.1016/j.freeradbiomed.2018.10.425

2012. Self-Assembly of a Dendron-Attached Tetrathiafulvalene: Gel Formation and Modulation in the Presence of Chloranil and Metal Ions. Small (Weinheim an der Bergstrasse, Germany).
DOI: 10.1002/smll.201101917

2004. Studies on the DT-diaphorase-catalysed reaction employing quinones as substrates: evidence for a covalent modification of DT-diaphorase by tetrachloro-p-benzoquinone. Chemico-Biological Interactions.
DOI: 10.1016/j.cbi.2003.10.006