103-33-3 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.
Check Digit Verification of cas no
The CAS Registry Mumber 103-33-3 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 1,0 and 3 respectively; the second part has 2 digits, 3 and 3 respectively.
Calculate Digit Verification of CAS Registry Number 103-33:
(5*1)+(4*0)+(3*3)+(2*3)+(1*3)=23
23 % 10 = 3
So 103-33-3 is a valid CAS Registry Number.
InChI:InChI=1/C12H10N2/c1-3-7-11(8-4-1)13-14-12-9-5-2-6-10-12/h1-10H
103-33-3Relevant articles and documents
Gas-Phase Chemistry of the Negative Ions Derived from Azo- and Hydrazobenzene
Ingemann, Steen,Fokkens, Roel H.,Nibbering, Nico M. M.
, p. 607 - 612 (2007/10/02)
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
McDonald, Richard N.,Chowdhury, A. Kasem,Setser, D. W.
, p. 6599 - 6603 (2007/10/02)
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.
