Naphthalene, the simplest condensed aromatic hydrocarbon, has the chemical formula CtenHeightIt is fused by two benzene rings sharing two adjacent carbon atoms. It is widely used as raw material for preparing dyes, resins, solvents, etc., and also as insect repellent.
On October 27, 2017, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization (WHO) was preliminarily collated for reference, and naphthalene was included in the list of Category 2B carcinogens.[3]
Insoluble in water, soluble in anhydrous ethanol, ether, benzene
chemical property
1. Oxidation of naphthalene
A mild oxidant yields quinone, and a strong oxidant yields anhydride.Naphthalene ring is easier to oxidize than side chain, so side chain oxidation cannot be used to prepare naphthoic acid.The rings with high electron cloud density are easy to be oxidized.for exampleα-Nitro naphthalene is oxidized to 3-nitrophthalic anhydride,α-Naphthylamine is oxidized to phthalic anhydride (the ring where the amino group is located is oxidized).
2. Reduction reaction (addition reaction) of naphthalene
Naphthalene can be added with 5 hydrogen to form decalin.
3. Electrophilic substitution of naphthalene
Naphthaleneα-Bit ratioβ-The electrophilic substitution reaction is more likely to occur in the.α-Both of the two resonances have complete benzene rings.β-There is only one resonance type with complete benzene ring.
The electrophilic substitution mainly occurs on the naphthalene ring, which is the same as the benzene ring (easy to replace, difficult to add), but the activity is stronger than the benzene ring.
Start from the C next to the two symmetrical C in the middle (the two carbon in the middle are not numbered), where carbon 1, 4, 5 and 8 have the same activity (calledαCarbon), carbon 2, 3, 6, and 7 have the same properties (calledβCarbon).
Normally,αCarbon activity greater thanβCarbon, substituent inαThis is controlled by dynamics. When the temperature is high,αThe substituents on the carbon will be transferred toβOn carbon.
However, the Friedel Crawford acylation reaction of naphthalene producesαBit sumβBit mixture.If nitromethane is used as solvent, β acylation products are mainly generated.[2]
Molecular structure data
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Molar refractive index
forty-four point zero nine
Molar volume (cmthree/mol）
one hundred and twenty-three point five
Isotonic specific volume (90.2K)
three hundred and eleven point one
Surface tension (dyne/cm)
forty point two
Dielectric constant (F/m)
two point eight two
Polarization (10-24cmthree）
seventeen point four eight[1]
Calculate chemical data
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Drainage parameter calculation reference value (XlogP)
nothing
Number of hydrogen bond donors
zero
Number of hydrogen bond receptors
zero
Number of rotatable chemical bonds
zero
Number of tautomers
zero
Topological molecular polar surface area (TPSA)
zero
Number of heavy atoms
ten
surface charge
zero
Complexity
eighty point six
Number of isotope atoms
zero
Determine the number of atomic geometric centers
zero
Number of atomic geometric centers in uncertainty
zero
Determine the number of chemical bond stereocenters
zero
Number of uncertain chemical bond stereocenters
zero
Number of covalent bond units
one[1]
purpose
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It is widely used as raw material for preparing dyes, resins, solvents, etc., and also as insect repellent.
In rabbits, 1 g/(kg · d), 3 days after oral administration, lens opacification was seen, and cataract was formed 20 days later.When rabbits inhaled saturated steam for 2h, 2-3 months every day, the number of red blood cells increased first and then decreased;400~500mg/mthreeFor 4 hours and 5 months every day, lens opacity can be seen.Mice inhale 60-500mg/mthree, 5 months later, the conditioned reflex was disordered, and respiratory system damage was found at autopsy.
The lowest toxic dose (TDLo) of 5925mg/kg was administered intraperitoneally from 1 to 15 days after pregnancy in rats, resulting in developmental abnormalities of musculoskeletal system and cardiovascular system.
carcinogenicity
IARC carcinogenicity review: G2B, suspected human carcinogen.
other
The lowest oral toxic dose (TDLo) of mice: 2400mg/kg (7~14 days of pregnancy), which affects the live birth index and survival index (such as the number of live births on the fourth day)[1]
Ecological data
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Ecotoxicity
LCfifty
1.37~3.8mg/L (96h) (fish)
Biodegradability
Aerobic biodegradation
12~480h
Anaerobic biodegradation
600~6192h
Non biodegradable
Photolysis half-life in aqueous phase
1704~13200h
Maximum optical absorption wavelength range of photolysis
310.5~220.5nm
Photooxidation half-life in water
1704~13200h
Photooxidation half-life in air
2.96~29.6h
Bioaccumulation
BCF
36.5~168 (carp, exposure concentration 0.15ppm, exposure time 8 weeks);23-146 (carp, exposure concentration 0.015ppm, exposure time 8 weeks).[1]
Storage method
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Precautions for storage: store in a cool and ventilated warehouse.Keep away from kindling and heat sources.The warehouse temperature should not exceed 35 ℃.Packing and sealing.It shall be stored separately from oxidant and shall not be mixed.Equip with corresponding types and quantities of fire-fighting equipment.The storage area shall be equipped with appropriate materials to contain leakage.
harmfulness
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Hazard characteristics
Combustible in case of open fire and high heat.It emits toxic and irritating smoke when burning.In contact with strong oxidants such as chromic anhydride, chlorate and potassium permanganate, strong reaction can occur, causing combustion or explosion.The powder and air can form an explosive mixture. When it reaches a certain concentration, it will explode when encountering Mars.
Environmental hazards
Migration in the environment Several experiments prove thatPolycyclic aromatic hydrocarbons(PAHs)Biodegradability。Low molecular weight polycyclic aromatic hydrocarbons (PAHs) such as naphthaleneAcenaphthene、AcenaphtheneIt can be rapidly degraded in the experimental study.For liquid with initial concentration of 5-10 mg/L, more than 90% of polycyclic aromatic hydrocarbons (PAHs) are biodegraded within 7 days.High molecular weight polycyclic aromatic hydrocarbons (PAHs) such as fluoranthene, benzo [a] anthracene, benzo (a) pyrene and anthracene are difficult to be biodegraded.
Health hazard: It has stimulating effect, and high concentration will cause hemolytic anemia and liver and kidney damage.It can lead to anemia or a significant reduction in the number of red blood cells, hemoglobin and blood cells.Naphthalene can cause some serious skin diseases for people who are sensitive to skin.
Acute poisoning: when inhaled high concentration naphthalene vapor or dust, eye and respiratory tract irritation, corneal opacity, headache, nausea, vomiting, anorexia, low back pain, frequency of urination, protein and red and white cells in urine appear.Optic neuritis and retinitis can also occur.In severe cases, toxic encephalopathy and liver damage may occur.Oral poisoning mainly causes hemolysis, liver and kidney damage, and even acute renal failure and liver necrosis.
Chronic poisoning: Repeated exposure to naphthalene vapor can cause headache, fatigue, nausea, vomiting and blood system damage.It can cause cataract, optic neuritis and retinopathy.Skin contact can cause dermatitis.[1-2]
Emergency Management
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Leakage emergency treatment
Isolate the leakage contaminated area and restrict access.Cut off the ignition source.It is recommended that emergency personnel wear self-contained breathing apparatus and general work clothes.Do not touch the leakage directly.Small amount of leakage: avoid raising dust, use non sparking tools to collect it in dry, clean and covered containers.Transport to an open place for detonation.Or incinerate on the spot if safety is guaranteed.Large amount of leakage: cover with plastic cloth and canvas to reduce flying.Use non sparking tools to collect and recycle or transport to waste disposal site for disposal.
Protective measures
Protective parts
Protective measures
respiratory system protection
Filter type gas mask (half mask) should be worn when exposed to high concentration steam;It is recommended to wear a self-priming filter type dust mask when it may be exposed to its dust.
Eye protection
Wear chemical safety goggles.
Body protection
Wear anti poison penetration work clothes.
Hand protection
Wear chemical resistant gloves.
other
Smoking, eating and drinking are prohibited at the work site.After work, take a shower and change clothes.
First aid measures
Exposure
First aid measures
Skin contact
Take off the contaminated clothes and wash the skin thoroughly with soapy water and clean water.
Eye contact
Lift the eyelids and wash them with flowing water or normal saline.Get medical attention.
inhalation
Quickly leave the site to fresh air.Keep the respiratory tract unobstructed.If breathing is difficult, give oxygen.If breathing stops, perform artificial respiration immediately and seek medical advice.
Ingestion
Drink enough warm water, induce vomiting, and seek medical advice.[1-2]
security information
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Safety terminology
S7：Keep container tightly closed.
Store in a tightly closed container.
S16：Keep away from sources of ignition - No smoking.
Keep away from ignition sources and no smoking.
S36/37：Wear suitable protective clothing and gloves.
Wear appropriate protective clothing and gloves.
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).
S46：If swallowed, seek medical advice immediately and show this container or label.
If ingested, seek medical advice immediately and show the container/label.
S60：This material and/or its container must be disposed of as hazardous waste.
The substance and its container must be disposed of as hazardous waste.
S61：Avoid release to the environment. Refer to special instructions/Safety data sheets.
Avoid releasing into the environment, refer to special instructions/safety receipt instructions.
S62：If swallowed, do not induce vomiting: seek medical advice immediately and show this container or label.
Do not induce vomiting after swallowing: seek medical advice immediately and show the container or label.
Risk terminology
R22：Harmful if swallowed.
It is harmful if swallowed.
R40：Possible risks of irreversible effects.
There may be risk of irreversible effects.
R50/53：Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment.
It is extremely toxic to aquatic organisms and may cause long-term adverse effects in the aquatic environment.
