1,2,3-Benzotriazole (azimidobenzene) is a heterocyclic organic compound with the chemical formula C 6 H 5 N 3 . It is used in photography as an anti-veterinary agent , in industry as a corrosion inhibitor, and also in analytical chemistry.
| Benzotriazole | |
|---|---|
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| Are common | |
| Systematic name | 1,2,3-Benzotriazole |
| Traditional names | 1H-Benzotriazole, 1,2,3-triazainden, azimidobenzene |
| Chem. formula | C 6 H 5 N 3 |
| Physical properties | |
| Molar mass | 119.13 g / mol |
| Density | 1.36 g / cm³ |
| Thermal properties | |
| T. melt. | 96–98.5 ° C |
| T. bale. | 350 ° C |
| Chemical properties | |
| Solubility in water | 2 g / 100 ml [1] |
| Classification | |
| Reg. CAS number | 95-14-7 |
| PubChem | |
| Reg. EINECS number | |
| Smiles | |
| Inchi | |
| RTECS | |
| Chebi | |
| ChemSpider | |
| Security | |
| LD 50 | 560 mg / kg (rat, oral)
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Content
Physical and chemical properties
Colorless or white (sometimes darker, even brown) crystals of a needle-like shape. It is well soluble in alcohol , benzene , toluene , methanol , practically insoluble in water. Molar mass of 119.13 g / mol. It has a melting point of 96–98.5 ° C [3] . At 210 ° C it spontaneously ignites.
Benzotriazole exhibits amphoteric properties [3] . It can be both protonated at position 3, forming salts with acids, and deprotonated at position 1:
Alkylation of benzotriazole occurs at position 1, with an excess of an alkylating agent, 1,3-dialkylbenzotriazolium salts are formed. Electrophilic substitution occurs at position 4 or 7 in an acidic environment. It forms 1,2,3-triazole-4,5-dicarboxylic acid in the reaction with perchlorates and potassium permanganate [3] .
The antiviral properties of benzotriazole and its derivatives are due to two mechanisms. First, they increase the activation energy of the reduction of silver halides by the developing substance . Secondly, they significantly slow down the diffusion rate of Ag + ions both inside the silver halide microcrystal and on its surface, which, in turn, slows down the process of reduction of these ions on metal silver sulfides and nuclei. Both of these mechanisms lead to improved selectivity of the manifestation [4] .
Getting
Get 1,2,3-benzotriazole by diazotization of o-phenylenediamine [3] :
Similarly, 1-substituted derivatives are obtained from o-phenylenediamines; oxidation of o-aminoazo compounds is used to obtain 2-substituted derivatives [3] .
Application
In analytical chemistry, they are used to isolate cadmium and nickel, for the gravimetric determination of copper (II) , silver (I) , zinc (II), osmium (VIII) compounds, and the titrimetric determination of silver (I) compounds [3] .
Used in industry as a corrosion inhibitor.
In photography, benzotriazole is used as an anti-veterinant [3] .
Derivatives of benzotriazole are used for light stabilization of polymers [3] .
Notes
- ↑ ICSC1091
- ↑ Fisher Scientific
- ↑ 1 2 3 4 5 6 7 8 Dovgilevich, 1988 .
- ↑ James, 1980 , p. 398-400.
Literature
- James T. The Theory of the Photographic Process = The theory of the photographic process / Per. 4th American ed. under the editorship of Kartuzhansky A.L. - 2nd Russian ed. - L .: “Chemistry”. Leningrad branch., 1980 .-- 672 p.
- Dovgilevich A.V. Benzotriazole: article // Chemical Encyclopedia / Editorial: Knunyants I. L. et al. - M .: Soviet Encyclopedia , 1988. - T. 1: A — Darzan. - S. 277. - 623 p.