103-33-3

Orange-red crystals or dark brown chunky solid.

AZOBENZENE(103-33-3) is an azo compound. Azo, diazo, azido compounds can detonate. This applies in particular to organic azides that have been sensitized by the addition of metal salts or strong acids. Toxic gases are formed by mixing materials of this class with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. Flammable gases are formed by mixing materials in this group with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides. This compound is incompatible with strong oxidizing agents.

This chemical is sensitive to air and light. Dust may form an explosive mixture in air. Insoluble in water.

Toxic; may cause liver injury. Questionable carcinogen.

An azo compound. Those engaged in azobenzene use in dye, rubber, chemical, and pesticide manufacturing.

Flash point data for this chemical are not available. AZOBENZENE is probably combustible.

Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; give artificial respiration with the aid of a pocket mask equipped with a oneway valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin. Keep victim warm and quiet. Effects of exposure (inhalation, ingestion or skin contact) to substance may be delayed. Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Medical observation is recommended for 24 to 48 hours after breathing overexposure, as pulmonary edema may be delayed. As first aid for pulmonary edema, a doctor or authorized paramedic may consider administering a drug or other inhalation therapy.

UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required.

Azo compounds can detonate. This applies in particular to organic azides that have been sensitized by the addition of metal salts or strong acids. Toxic gases are formed by mixing materials of this class with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. Flammable gases are formed by mixing materials in this group with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides. This chemical is sensitive to prolonged exposure to heat. This chemical is incompatible with strong oxidizing agents.

Azobenzene is a well-known derivative of stimulus-responsive molecular switches and has shown superior performance as a functional material in biomedical applications.
Azobenzene is a typical photo-responsive molecule that isomerizes from its planar trans-form to the non-planar cis-form after UV-light irradiation with a wavelength between 300 nm and 400 nm (lmax is around 330 nm). Interestingly, the system reverts from the cis-form to the trans-form after further irradiation with visible light (wavelength over 400 nm). This process is completely reversible, and the azobenzene group does not decompose or induce undesirable side reactions even on repeated trans-cis isomerization. By introducing azobenzenes into DNA through D-threoninol as a linker, Asanuma and co-workers succeeded in achieving photo-regulation of:
Formation and dissociation of a DNA duplex
Transcription by T7-RNA polymerase reaction

Azobenzene is a combustible, orange-red crystalline solid.

orange to red crystals

acaricide, insecticide.
Azobenzene can be used as an optical trigger for the design and synthesis of a large variety of photoresponsive systems.

Impurity in the production of Phenylbutazone (P319570).

Precursor for dyes, for polymers.

ChEBI: A molecule whose structure comprises two phenyl rings linked by a N=N double bond; the parent compound of the azobenzene class of compounds.

Canadian Journal of Chemistry, 38, p. 2526, 1960 DOI: 10.1139/v60-344
Chemical and Pharmaceutical Bulletin, 36, p. 1529, 1988 DOI: 10.1248/cpb.36.1529
Tetrahedron Letters, 25, p. 1259, 1984 DOI: 10.1016/S0040-4039(01)80128-3

lor Code—Blue: Health Hazard/Poison: Storein a secure poison location. Prior to working with thischemical you should be trained on its proper handling andstorage. Store under an inert atmosphere in a freezer orAzobenzene 301refrigerator. Protect from air and light. Sources of ignition, such as smoking and open flames, are prohibitedwhere this chemical is used, handled, or stored in a mannerthat could create a potential fire or explosion hazard. Aregulated, marked area should be established where thischemical is handled, used, or stored in compliance withOSHA Standard 1910.1045.

Ordinary azobenzene is nearly all in the trans-form. It is partly converted into the cis-form on exposure to light [for isolation see Hartley J Chem Soc 633 1938, and for spectra of cis-and trans-azobenzenes, see Winkel & Siebert Chem Ber 74B 6701941]. trans-Azobenzene is obtained by chromatography on alumina using 1:4 *C6H6/heptane or pet ether, and it crystallises from EtOH (after refluxing for several hours) or hexane. All operations should be carried out in diffuse red light or in the dark. [Beilstein 16 IV 8.]