103-33-3

Hazards Identification

Pictogram(s):

Signal:

Danger

GHS Hazard Statements:

H302: Harmful if swallowed [Warning Acute toxicity, oral]
H332: Harmful if inhaled [Warning Acute toxicity, inhalation]
H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]
H350: May cause cancer [Danger Carcinogenicity]
H373 **: Causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]
H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]
H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

Precautionary Statement Codes:

P203, P260, P261, P264, P270, P271, P273, P280, P281, P301+P317, P304+P340, P317, P318, P319, P330, P391, P405, and P501

Hazard Classes and Categories:

Carc. 1B
Muta. 2
Acute Tox. 4 *
STOT RE 2 *
Aquatic Acute 1
Aquatic Chronic 1
Acute Tox. 4 (100%)
Acute Tox. 4 (99.11%)
Muta. 2 (99.11%)
Carc. 1A (100%)
STOT RE 2 (100%)
Aquatic Acute 1 (99.11%)
Aquatic Chronic 1 (100%)
Acute toxicity - category 4
Germ cell mutagenicity - category 2
Carcinogenicity - category 1B
Specific target organ toxicity (repeated exposure) - category 2
Hazardous to the aquatic environment (acute) - category 1
Hazardous to the aquatic environment (chronic) - category 1
Acute toxicity (Oral) - Category 4
Germ cell mutagenicity - Category 2
Carcinogenicity - Category 2
Specific target organ toxicity - Repeated exposure - Category 2 (liver)
Hazardous to the aquatic environment (Acute) - Category 1
Hazardous to the aquatic environment (Long-term) - Category 1
Carcinogens

Hazards Summary:

A skin, eye, and respiratory tract irritant; Oral administration causes liver damage in sub-chronic study of dogs and chronic study of rats; Methemoglobinemia followed by anemia observed in sub-chronic studies of mice and rats; Emergency treatment: Aniline; Aniline can induce methemoglobinemia, secondary hemolytic anemia, and liver damage. [HSDB] Sensitive to air and light; Dust mixtures with air may be explosive; A skin, eye, and respiratory tract irritant; Chronic exposure may cause effects to liver, kidneys, nervous system, and bone marrow; Can be absorbed through skin; [CAMEO] Evidence for carcinogenicity in rats but not in mice; [NTP] An irritant; [Alfa Aesar MSDS]

Usage

Synthesis Reference(s)

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

Air & Water Reactions

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

Reactivity Profile

AZOBENZENE 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. AZOBENZENE is incompatible with strong oxidizing agents.

Hazard

Toxic; may cause liver injury. Questionable carcinogen.

Fire Hazard

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

Safety Profile

Moderately toxic by ingestion and possibly other routes. Questionable carcinogen with experimental carcinogenic, neoplastigenic, and tumorigenic data. When heated to decomposition it emits toxic fumes of NOx.

Potential Exposure

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

Shipping

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

Purification Methods

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.]

Incompatibilities

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.

InChI:InChI=1/C12H10N2/c1-3-7-11(8-4-1)13-14-12-9-5-2-6-10-12/h1-10H

Upstream product

• 74586-02-0 phenylnitrene anion radical 
• 622-37-7 Phenyl azide 
• 17082-12-1 trans-azobenzene 

Downstream Products

• 2819-03-6 1-adamantyl radical 
• 1227476-15-4 Azobenzene 
• 68525-40-6 C₁₁H₁₅ 
• 97732-44-0 azobenzene dianion 
• 2154-56-5 benzyl radical 
• 2348-55-2 sec-Butyl-Radikal 

Related news

Visible light-, pH-, and cyclodextrin-responsive AZOBENZENE (cas 103-33-3) functionalized polymeric nanoparticles08/15/2019

Multiple stimuli-responsive nanoparticles that could respond to visible-light, pH and host-guest interactions were fabricated by self-assembly of tetra-ortho-methoxy-substituted azobenzene (mAzo) functionalized poly(dimethylaminoethyl methacrylate) (PDMAEMA) (PDMAEMA-mAzo), which was synthesized...detailed

Bioactivatable Reductive Cleavage of AZOBENZENE (cas 103-33-3) for Controlling Functional Dumbbell Oligodeoxynucleotides08/13/2019

Application of stimuli-responsive bioactive molecules is an attractive strategy due to use for target special tissues and cells. Here, we reported synthesis of an azo-linker, 2,2’-dimethoxyl-4,4’-dihydroxymethylazobenzene (mAzo), which was more effectively recognized and cleaved by reducing gl...detailed

p-Type and n-type AZOBENZENE (cas 103-33-3) nanocluster immobilized graphene oxide nanocomposite08/12/2019

In this work, we have successfully synthesized azobenzene nanocluster from azobenzene molecules through a bottom-up approach. The synthesized azobenzene nanocluster shows beautiful green fluorescence and well dispersed in aqueous medium. Interestingly, the photoswitchable property of azobenzene ...detailed

Light-induced healing in AZOBENZENE (cas 103-33-3) bridged silsesquioxanes08/11/2019

Intrinsic healable polymers are materials capable of repairing itself through its chemical nature, in order to improve stability and durability and to restore the lost functionalities or properties.In this study, azobenzene (AZO) moieties were incorporated into a previously reported bridged sils...detailed

Relevant academic research and scientific papers

Gas-Phase Chemistry of the Negative Ions Derived from Azo- and Hydrazobenzene

The proton affinities of the azobenzene radical anion and the conjugate base of hydrazobenzene have been determined to be 1465 kJ mol-1 and 1514 kJ mol-1, respectively, with the use of a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer equipped with an external ion source.The proton affinities lead in combination with a measured electron affinity of azobenzene (55 kJ mol-1) to a N-H bond dissociation energy (BDE) of 306 kJ mol-1 for hydrazobenzene while the N-H BDE of the PhNHN.Ph radical is estimated to be 208 kJ mol-1.The difference between the N-H BDE values of 98 kJ mol-1 approximates the ?-bond energy of the nitrogen-nitrogen bond in azobenzene.The reaction of the PhN.N-Ph and PhNHN-Ph ions with derivatives of trifluoroacetic acid are characterized.The occurrence of dissociative electron transfer instead of SN2 substitution in reactions of the azobenzene radical anion with halogen-substituted methanes is discussed.

Gas-Phase Generation of Phenylnitrene Anion Radical - Proton Affinity and ΔHf0 of PhN-. and Its Clustering with ROH Molecules

Phenylnitrene anion radical (PhN-.) was prepared in a flowing afterglow apparatus by dissociative electron attachement of phenyl azide (PhN3).PhN-. undergoes a very slow reaction with PhN3, producing PhN4Ph-. and PhN2Ph-. in a ratio of 4:1.The proton affinity pf PhN-. was bracketed from kinetic studies with various potential proton donors, PA(PhN-.) = 372 +/- 2 kcal mol-1, from which ΔHf0(PhN-.) = 60 +/- 2 kcal mol -1 was calculated.With alcohols which are too weakly acidic to directly protonate PhN-. , a sequence of bimolecular reactions is observed involving ROH; PhN-. -> PhN-.(HOR) -> PhNH. + RO-(HOR) -> RO-(HOR)x.Although the first step of the sequence is slow, the second step, a cluster-to-cluster transformation, is fast.The related reaction sequence of PhN-. reacting with HOH involves the ions PhN-. -> PhN-.(HOH) -> PhN-.(HOH)2 -> PhNH. + HO-(HOH)2 -> HO-(HOH)x with the third reaction as the fast step.The relationship of these sequential processes to acidities and basicities found in solution is discussed.Of the five observed reaction channels for PhN-. with CH3CN, the major channel yields the adduct m/z 132 and a minor channel produces the M-1 species, m/z 131.Additions by PhN-. to Cα or N or CH3CN are considered to account for these product anions.The reaction of PhN-. with (CH3)3CCN also yields its adduct.