Nitrogen tetroxide is a kind ofinorganic compound, chemical formula is NtwoOfour, colorless gas under normal temperature and pressure, mainly used for preparationnitric acid、Nitrating agent、Oxidant、catalyzerAcrylate polymerization inhibitor, etc.
Nitrogen tetroxide and nitrogen dioxide are converted to each other according to the following equation:
When the temperature rises, the reaction proceeds in the direction of generating nitrogen dioxide;Therefore, in fact, the finished product of nitrogen tetroxide is a balanced mixture with nitrogen dioxide.Nitrogen tetroxide reacts with water to formnitric acidandNitrite[1]：
Reaction equation of unsymmetrical dimethylhydrazine and nitrogen tetroxide:[5-6]
application area
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It is mainly used to prepare nitric acid, nitrating agent, oxidant, catalyst, acrylate polymerization inhibitor, etc.
Calculate chemical data
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Reference value for drainage parameter calculation (XlogP): 0.4[3]
Number of hydrogen bond donors: 0[3]
Number of hydrogen bond receptors: 4[3]
Number of rotatable chemical bonds: 0[3]
Number of tautomers: 0
Topological molecular polar surface area: 91.6[3]
Number of heavy atoms: 6[3]
Surface charge: 0[3]
Complexity: 60.5[3]
Number of isotope atoms: 0[3]
Determine the number of atomic structure centers: 0[3]
Number of uncertain atomic structure centers: 0[3]
Determine the number of chemical bond structure centers: 0[3]
Number of uncertain chemical bond structure centers: 0[3]
Number of covalent bond units: 1[2]
Molecular structure data
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Molar refractive index: 14.09[3]
Molar volume (cmthree/mol）：54[3]
Isotonic specific volume (90.2K): 149.2[3]
Surface tension (dyne/cm): 57.9[3]
Polarization (10-24cmthree）：5.58[2]
N atom with sptwoThe hybrid orbitals form bonds, and the molecules are planar molecules.
NtwoOfourIt can be formed by combining two nitrogen dioxide molecules.One of the 2s electrons of the central atom N of the nitrogen dioxide molecule is excited to pzTrack, then adopt sptwoHybridization, forming one with two oxygen atoms (adopting sp hybridization)σ bond；P of nitrogenzP of two electrons and two oxygen atoms in the orbitalzOne electron in the orbit forms three atoms and four electronspi bond；Unbounded sp of nitrogen atom in every two nitrogen dioxide moleculestwoThe hybrid orbits overlap to form a σ bond, thus forming an NtwoOfourMolecules.To sum up, each NtwoOfourThere are five σ bonds in the molecule, and two three atom four electron π bonds form one six atom eight electronLarge π bondThe shape of the molecule is similar to that of ethylene.[1]
security information
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Safety terminology
S9：Keep container in a well-ventilated place.
Keep the container in a well ventilated place.
S26：In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
After eye contact, immediately flush with plenty of water and seek medical advice.
S28：After contact with skin, wash immediately with plenty of ... (to be specified by the manufacturer).
After skin contact, immediately use a large amount of(designated by the manufacturer).
S36/37/38：Wear suitable protective clothing, gloves and eye/face protection.
Wear appropriate protective clothing, gloves and eye/face protection.
S45：In case of accident or if you feel unwell, seek medical advice immediately (show the lable where possible).
In case of an accident or feeling unwell, seek medical advice immediately (show the label if possible).
Risk terminology
R26：Very toxic by inhalation.
Very toxic by inhalation.
Toxicology
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1. Acute toxicity
LCfifty：126mg/mthree(Inhalation of rats, 4h)
2. Subacute and chronic toxicity
Rats and rabbits at 15~47mg/mthree, long-term inhalation may cause pulmonary edema.
Sister chromatid exchange: 5 ppm (October) in hamster lung (continuous).
4. Teratogenicity
Inhalation of 40% of the lowest toxic dose (TCLo) 8~10 days after pregnancy in rats resulted in malformation of musculoskeletal system development.
5. Others
The lowest inhalation toxic concentration (TCLo) of rats: 8.5 μ g/mthree(24h) (1~22d pregnancy), causing embryotoxicity and stillbirth.
LCLo inhaled by human: 200ppm (1min);TCLo: 6200ppb (10min), which can cause pulmonary edema.
Emergency Management
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Leakage emergency treatment
Evacuate the personnel in the leakage contaminated area to the windward place quickly, isolate them, and strictly restrict access.It is recommended that emergency personnel wear self-contained positive pressure respirators and anti poison clothing.Cut off the leakage source as much as possible.If it is gas, ventilate reasonably to accelerate diffusion.Dilute and dissolve with spray water.Build a dike or dig a pit to collect a large amount of wastewater generated.Leaking containers shall be properly treated, repaired and inspected before reuse.If it is liquid, wash it with a large amount of water, and put it into the waste water system after dilution.In case of a large amount of leakage, build a dike or dig a pit to receive it;Spray water to cool and dilute vapor.Use explosion-proof pump to transfer to tank car or special collector for recycling or transport to waste disposal site.
Protective measures
Respiratory system protection: wear a self-priming filter gas mask (full face mask) when the concentration in the air exceeds the standard.In case of emergency rescue or evacuation, it is recommended to wear an air respirator.
Eye protection: protection has been made in respiratory system protection.
Body protection: wear adhesive tape anti-virus clothing.
Hand protection: wear rubber gloves.
Others: Smoking, eating and drinking are prohibited at the work site.Keep good hygiene habits.When entering tanks, confined spaces or other high concentration areas for operation, someone must supervise.
First aid measures
Skin contact: Take off contaminated clothes and wash with flowing water.
Eye contact: immediately lift the eyelid and flush with flowing water.
Inhalation: quickly leave the site to a place with fresh air.Keep the respiratory tract unobstructed.If breathing is difficult, give oxygen.If breathing stops, perform artificial respiration immediately.Get medical attention.
Ingestion: drink enough warm water, induce vomiting, and seek medical advice.
Hazard category
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Oxidizing gas, category 1
Acute Toxicity of Pressurized Gases - Inhalation, Category 2*
Skin corrosion/irritation, Category 1B
Serious eye injury/eye irritation, category 1
Specific target organ toxicity - single exposure, Category 3 (respiratory tract irritation)[4]
