Phenol (C 6 H 5 OH) is a colorless needle-like crystal with special odor, which is toxic and is an important raw material for producing some resins, fungicides, preservatives and drugs (such as aspirin). It can also be used for disinfection of surgical instruments and excreta treatment, skin sterilization, itching relief and otitis media. Melting point 43℃, slightly soluble in water at room temperature, easily soluble in organic solvents; When the temperature is higher than 65℃, it can be miscible with water in any proportion. Phenol is corrosive, which will denature local protein after contact, and its solution can be washed with alcohol when it touches the skin. A small part of phenol is exposed to air and oxidized into quinone by oxygen, which turns pink. When ferric ions turn purple, this method is usually used to test phenol.
On October 27th, 217, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization was preliminarily collated for reference, and phenol was in the list of three types of carcinogens. Chinese name: Phenol English name: phenol alias: carbolic acid, phenol, hydroxybenzene chemical formula: C6H5OH molecular weight: 94.11 CAS accession number: 18-95-2 EINECS accession number: 23-632-7 melting point: 43℃ boiling point: 181.9℃ water solubility: slightly soluble in cold water, at 65℃. Soluble in ethanol, ether, chloroform and glycerol. Density: 1.71g/mL(25℃). Appearance: colorless or white crystals with special odor. It turns pink in air and light. Flash point: 185℉/85℃. Application: chemical synthesis, oilfield industry, electroplating, solvent. Medical safety description: S26, S28, S45, S24/S25, S36/S37/S39. Hazard symbols: F (flammable), T (toxic) and C (corrosive). R48/2/21/22 Transport number of dangerous goods: UN 2821 6.1/PG 2 Chemical properties: weak acidity, high toxicity, mutagen, reductive stability: stable banned compounds: strong oxidant, strong acid and strong alkali storage method: cool and ventilated, low temperature and dark, Pay attention to the leakage PSA: 2.23 logp: 1.3922 refractive index: n2/D 1.5418 customs code: 29711 discovery history, molecular structure, physical properties, chemical properties, acid-base reaction, color reaction, substitution reaction, redox reaction, condensation reaction, preparation method, sulfonation method, cumene method, chlorobenzene hydrolysis method, Crude phenol refining method, benzene oxidation method, toluene oxidation method, matters needing attention, health hazards, first aid measures, fire protection measures, emergency treatment of leakage, handling and storage, allowable limit, allowable limit in water, related experiments, acidity of phenol, communication phenomenon, experimental conclusion, demonstration experiment, application field, industry, medical treatment and degradation characteristics research, it is found that historical phenol was discovered by German chemist Runge F in 1999. It was the famous British doctor Lester who made phenol famous for the first time. Lister found that most of the causes of death after operation were wound suppurative infection. Occasionally, dilute phenol solution is used to spray surgical instruments and doctors' hands, and as a result, the infection of patients is significantly reduced. This discovery makes phenol a powerful surgical disinfectant. Lister is also known as the "father of surgical disinfection". Molecular structure Phenol molecules are composed of a hydroxyl group directly attached to the benzene ring. Because of the stability of benzene ring, such a structure will hardly be transformed into a ketone structure. The vibration structure of phenol is shown in the upper right figure. The oxygen atom of phenolic hydroxyl is hybridized by sp2, which provides a pair of lone electrons to form delocalization bonds with the six carbon atoms of benzene ring. The large π bond strengthens the acidity of enol, and the electron pushing effect of hydroxyl group strengthens the polarity of O-H bond, so the hydrogen of hydroxyl group in phenol can be ionized. The phenate anion has a * * vibration structure as shown in the figure on the right: molar refractive index: 28.13
molar volume (m3/mol): 87.8
isotonic specific volume (9.2 k): 222.2
surface tension (dyne/ Cm): 4.9
Polarization: 11.15 Physical properties Relative vapor density (air = 1): 3.24 Refractive index 1.5418 Saturated vapor pressure (kPa): .13 (4.1℃) Combustion heat (kJ/mol): 35.6 Critical temperature (℃): 419.2 Critical pressure (MPa). Logarithmic value of water distribution coefficient: 1.46 upper explosive limit% (v/v): 8.6 ignition temperature (℃): 715 lower explosive limit% (v/v): 1.7 solubility: miscible in ether, chloroform, glycerol, carbon disulfide, vaseline, volatile oil and strong alkali aqueous solution. It is easily soluble in organic solvents such as ethanol, glycerol, chloroform and ether at room temperature, slightly soluble in water at room temperature, liquefied when mixed with about 8% water, miscible with water above 65℃ and almost insoluble in petroleum ether. Chemical properties can absorb moisture in the air and liquefy it. It has a special odor, and the extremely dilute solution has a sweet taste. Very corrosive. Strong chemical reaction ability. React with aldehyde and ketone to produce phenolic resin, bisphenol A and acetic anhydride; Salicylic acid reacts to produce phenyl acetate and salicylate. Halogenation, hydrogenation, oxidation, alkylation, carboxylation, esterification, etherification and other reactions can also be carried out. Phenol is a solid at normal temperature, and it can't react with sodium smoothly. If the experiment is carried out by heating and melting phenol, and then adding metal sodium, phenol will be easily reduced, and the color of phenol will change when heating, which will affect the experimental effect. Some people take the following methods to experiment in teaching, which is simple to operate and has achieved satisfactory experimental results. Add 2-3 ml of anhydrous ether to a test tube, take a piece of metallic sodium the size of soybean grain, use filter paper to absorb the kerosene on the surface, and put it into ether, and it can be seen that sodium does not react with ether. Then add a small amount of phenol to the test tube and oscillate. At this time, it can be observed that sodium reacts rapidly in the test tube and produces a large amount of gas. The principle of this experiment is that phenol is dissolved in ether, so that the reaction between phenol and sodium can proceed smoothly. Acid-base reaction Phenol is a kind of phenolic substance with weak acidity, which can react with alkali: PhOH+NaOH→PhONa+H 2 O phenol Ka=1.28×1 -1, and its acidity is between two levels of ionization of carbonic acid, so phenol cannot react with weak bases such as NaHCO 3: pho ˉ+CO2+H2O → pho+HCO3 ˉ This reaction phenomenon: carbon dioxide. Reason: Phenol is precipitated due to its low solubility. Color reaction phenol turns purple when it meets ferric chloride solution, because phenol ion forms a colored complex with Fe. 6 Hoh+FeCl 3 → H 3 [Fe (Oph) 6] (purple) +3HCl substitution reaction electrophilic substituted phenol can produce benzene-like electrophilic substitution on the ring because of its benzene ring structure, such as nitration and halogenation. Compared with the corresponding reactions of benzene, it can be found that the substitution on the ring of phenol is much easier than that of benzene. This is because hydroxyl group has an electron-donating effect, which increases the electron cloud density of benzene ring. It is worth noting that the electrophilic substitution of phenol always occurs in the ortho and para positions of hydroxyl groups. This is the * * nature of electron-donating groups such as hydroxyl groups. Substitution on Phenol Hydroxyl The hydrogen atom on Phenol Hydroxyl can be substituted by carbon-containing groups to form ethers or esters. Redox phenol will turn pink in air for a long time because benzoquinone is formed: the oxidation product of phenol is usually p-benzoquinone. Br 2 can also be used as oxidant in this reaction. Condensation reaction Phenol and formaldehyde are condensed under the catalysis of acid or alkali to produce phenolic resin. Preparation method Phenol was first recovered from coal tar, and at present most of it is synthesized. By the mid-196s, the technical route of producing phenol and acetone by cumene method had developed to account for half of the world's phenol production. At present, the phenol produced by this process has accounted for more than 9% of the world's phenol production. Other production processes include toluene chlorination, chlorobenzene and sulfonation. There are two production methods in China: cumene method and sulfonation method. Because sulfonation consumes a lot of sulfuric acid and caustic soda, China will only keep a few sulfonation devices and gradually focus on cumene production. Sulfonation method takes benzene as raw material, sulfonates benzene sulfonic acid with sulfuric acid, neutralizes it with sulfurous acid, then carries out alkali melting with caustic soda, and then carries out sulfonation and vacuum distillation. Consumption quota of raw materials: pure benzene 14kg/t, sulfuric acid (98%)1284kg/t, sodium sulfite 1622kg/t and caustic soda (1%) 12kg/t.. Cumene is produced by propylene and benzene in the presence of aluminum trichloride catalyst, and cumene is oxidized to cumene peroxide, which is then decomposed by sulfuric acid or resin. Phenol and acetone are obtained simultaneously. About .6t acetone is co-produced per ton of phenol. Raw material consumption quota: benzene 115kg/t, propylene 6kg/t, yield 7% to 8%. Chlorobenzene hydrolysis method Chlorobenzene is catalytically hydrolyzed with caustic soda aqueous solution at high temperature and high pressure of 371 degrees Celsius to generate sodium benzene, which is then neutralized with acid to obtain phenol. Crude phenol refining method is obtained by refining crude phenol from coal tar. In the presence of solid molybdenum catalyst, benzene is oxidized by chlorine at high temperature to produce chlorobenzene and water, and chlorobenzene is catalytically hydrolyzed to obtain phenol and hydrogen chloride, which can be recycled. Toluene oxidation method Toluene is oxidized by air under the action of cobalt salt catalyst to produce benzoic acid, and then benzoic acid reacts with air and water vapor under the action of copper catalyst to convert into phenol and carbon dioxide. Precautions Health hazards Phenol has a strong corrosive effect on skin and mucosa, which can inhibit the central nervous system or damage the liver and kidney function. Acute poisoning: Inhalation of high concentration steam can cause headache, dizziness, fatigue, blurred vision and pulmonary edema. Accidental ingestion causes digestive tract burns, burning pain, exhaled breath with phenol smell, vomit or stool with blood, gastrointestinal perforation, shock, pulmonary edema, liver or kidney damage, acute renal failure, and death from respiratory failure. Eye contact can cause burns. Can be absorbed by burned skin and cause acute renal failure after a certain incubation period. Chronic poisoning: it can cause headache, dizziness, cough, loss of appetite, nausea and vomiting, and in severe cases, proteinuria. Can cause dermatitis. Environmental hazard: it is seriously harmful to the environment and can cause pollution to water and atmosphere. Danger of explosion: this product is flammable, highly toxic and corrosive, which can cause burns to human body. First-aid measures 1 Skin contact: Take off the contaminated clothes immediately, wipe them with glycerin, polyethylene glycol or a mixture of polyethylene glycol and alcohol (7:3), and then wash them thoroughly with water. Or rinse with plenty of flowing water for at least 15 minutes. See a doctor. Eye contact: lift the eyelid immediately and rinse thoroughly with plenty of flowing water or normal saline for at least 15 minutes. See a doctor. Inhalation: leave the site quickly and go to fresh air. Keep the respiratory tract unobstructed. If breathing is difficult, give oxygen. If breathing stops, give artificial respiration immediately. See a doctor. 3 Ingestion: immediately give 15 ~ 3 ml of vegetable oil. Vomiting See a doctor. Fire protection measures 1 Hazard characteristics: flammable in case of open fire and high heat. Harmful combustion products: carbon monoxide and carbon dioxide. 3 Fire extinguishing method: Firefighters must wear gas masks and full-body fire suits to extinguish the fire in the upwind direction. Fire extinguishing agent: water, anti-soluble foam, dry powder, carbon dioxide. Emergency treatment of leakage 1. Emergency treatment: isolate the leakage contaminated area and restrict access. Cut off the fire. It is recommended that emergency personnel wear dust masks (full-face masks) and protective clothing. 2 Small amount of leakage: cover with dry lime and soda ash. 3. Large amount of leakage: collected and recycled or transported to waste disposal sites for disposal. Operation, disposal and storage 1. Precautions for operation: Close the operation and provide sufficient local ventilation. Isolate as much as possible. Operators must be specially trained and strictly abide by the operating procedures. It is recommended that the operator wear a self-priming filter dust mask, chemical safety glasses, penetrating gas-proof clothing and chemical-proof gloves. Stay away from fire and heat sources, and smoking is strictly prohibited in the workplace. Use explosion-proof ventilation system and equipment. Avoid producing dust. Avoid contact with oxidants, acids and alkalis. When handling, handle lightly to prevent the packaging and containers from being damaged. Equipped with corresponding varieties and quantities of fire fighting equipment and leakage emergency treatment equipment. Empty containers may leave harmful substances. 5.2 Precautions for storage: Store in a cool and ventilated warehouse. Stay away from fire and heat sources. Avoid light. The storage temperature shall not exceed 3℃ and the relative humidity shall not exceed 7%. The package is sealed. It should be stored separately from oxidants, acids, alkalis and edible chemicals, and should not be mixed. Equipped with corresponding varieties and quantities of fire fighting equipment. The storage area should be equipped with suitable materials to contain the leakage. The "five pairs" management system of extremely toxic substances should be strictly implemented. Allowable limit USA TWA: 19 mg/m? 3, ACGIH US IDLH: 1 ppm UK TWA: 19 mg/m? 3. HSE Germany MAC: 19 mg/m? 3, DFG former Soviet Union MAC: .1 mg/m? 3 (residential area determination: sodium hydroxide is collected in a bubbler, and then it is desorbed by sulfuric acid and analyzed by gas chromatography. The allowable limit in water is the former Soviet Union MAC: .1 mg/L (drinking water) and China MAC: .2 mg/L. Determination: it is extracted by dichloromethane, and the acidity of related experimental phenol is analyzed by gas chromatography with flame ionization or electron detector or gas chromatography plus mass spectrometry. 1. 2. Take a small amount of phenol solid in three test tubes, and add 2-3 ml of sodium hydroxide solution, 2-3 ml of sodium carbonate solution and 2-3 ml of sodium bicarbonate solution to them respectively, fully oscillate, observe and compare the phenomena (pay attention to whether there are bubbles in the test tubes with salt solution. 3. Take 2mL of sodium hydroxide solution in the test tube, add 2-3 drops of phenolphthalein test solution, and then add a small amount of phenol solid to observe the color change. Communication phenomenon 1. Phenol can't turn litmus red. 2. Phenol solid is easily soluble in sodium hydroxide solution and sodium carbonate solution, and no bubbles are generated; Insoluble in sodium bicarbonate solution. 3. Phenol gradually lightens the red solution (sodium hydroxide solution with phenolphthalein test solution). The experimental results show that phenol has weak acidity, and its acidity is between carbonic acid and bicarbonate ion. The acidity of phenol is too weak to make litmus reagent red. (The color change range of litmus test solution is: pH 5 ~ 8) Demonstration experiment In the phenol solution just made, sodium hydroxide solution was added dropwise while shaking until it was just clear, and the product was sodium phenolate. Continuously introducing carbon dioxide gas, the solution becomes turbid again (carbon dioxide and water generate carbonic acid, carbon