What Is Dinitrobenzene?
Dinitrobenzene is an aromatic nitro compound with white to pale yellow needle/plate-like crystals. Its chemical formula is C6H4N2O4 and its molecular weight is 168.11.
Dinitrobenzene has three isomers depending on the position of substitution of the nitro group:
- The 1- and 2-substituted forms are called o(ortho)-dinitrobenzene or 1,2-dinitrobenzene.
- The 1- and 3-substituted forms are called m(meta)-dinitrobenzene or 1,3-dinitrobenzene
- The 1- and 4-substituted forms are called p(para)-dinitrobenzene or 1,4-dinitrobenzene.
Uses of Dinitrobenzene
1. Dye Intermediate
m-Dinitrobenzene, which can be easily synthesized industrially, has been used as a dye intermediate. m-Dinitrobenzene can be partially reduced with sodium sulfide, etc. m-Nitroaniline can be reduced with iron-hydrochloric acid to yield m-Phenylenediamine.
m-Phenylenediamine obtained by the above method is used as an intermediate for azo basic dyes, mordant dyes, direct dyes, and acid dyes.
In addition, m-phenylenediamine synthesized from m-dinitrobenzene is used as a raw material for ion exchange resins, photographic products such as developing solutions, and aramid fiber and spandex.
2. Color-Forming Reagent
m-Dinitrobenzene is also used as a coloring reagent in sexual function tests. 17-ketosteroids are produced when testosterone in the blood is metabolized.
When 17-ketosteroids, which are excreted with urine, are brought into contact with m-dinitrobenzene, they turn red. 17-ketosteroid detection is an indicator of androgen production in men.
Properties of Dinitrobenzene
1. O-Dinitrobenzene
O-Dinitrobenzene has a CAS registration number of 528-29-0. It is solid at room temperature with a melting point of 118 °C and a boiling point of 318 °C. It is soluble in benzene and chloroform and practically insoluble in water.
2. M-Dinitrobenzene
M-Dinitrobenzene has a CAS registration number of 99-65-0. Its melting point is 89.6 °C and boiling point is 297 °C. It is a solid at room temperature. It is very soluble in acetone, ethanol, ethyl acetate, and chloroform, soluble in ether, and practically insoluble in water.
3. P-Dinitrobenzene
P-Dinitrobenzene has a CAS registration number of 100-25-4. It is solid at room temperature with a melting point of 174 °C and a boiling point of 299 °C. p-Dinitrobenzene has the highest melting point because it is the most symmetrical of the three isomers. It is soluble in acetone, benzene, ethyl acetate, and chloroform, and virtually insoluble in water.
Other Information about Dinitrobenzene
1. Production Process of Dinitrobenzene
m-Dinitrobenzene is obtained by nitration of benzene with a mixture of nitric and sulfuric acids and further nitration of the synthesized intermediate, nitrobenzene, under the same conditions.
2. Precautions for handling
Dinitrobenzene reacts violently with strong oxidizers, strong bases, and reducing metals (tin, zinc), creating a fire and explosion hazard. Avoid contact with the above mentioned incompatible hazardous materials. It should be used in a draft chamber with local exhaust ventilation, and personal protective equipment should be worn when using.
Dinitrobenzene is flammable. If mixed with air in powder or granular form, it may cause a dust explosion and may also explode without air due to heating. It should be kept away from high temperatures, direct sunlight, shock, heat, flames, sparks, static electricity, and sparks.
In case of fire
When burning, it produces toxic gases and nitrogen oxides. Use water spray, foam, powder extinguisher, carbon dioxide, extinguishing sand, etc. to extinguish fire. Do not use a stick injection water.
In case of skin contact
Avoid contact with skin as contact may cause allergic skin reactions. Always wear protective clothing such as a lab coat or work clothes and protective gloves when using the product. Never roll up the sleeves of protective clothing during use.
In the event of skin contact, wash off with soap and plenty of water. If on clothing, remove and isolate all contaminated clothing. If skin irritation or rash develops or symptoms persist, seek medical attention.
In case of eye contact
This product is highly irritating to the eyes. Always wear protective glasses or goggles when using this product.
In case of eye contact, rinse cautiously with water for several minutes. If wearing contacts, remove them if they can be easily removed and rinse thoroughly. Seek immediate medical attention.
Storage
Store in a tightly closed, light-shielding polyethylene container. Store locked up in a well ventilated, cool place away from direct sunlight.