Fenolo – Wikipedia

Phenol
Name IUPAC
phenol
Abbreviations
Ph-OH
Alternative names
phenic acid carolic acid benzenolo hydroxybenzene
General characteristics
Brute or molecular formula	C 6 H 6 O
Molecular mass (U)	94.11
I wait	colorless crystallines color
The number of cas	108-95-2
Einecs number	203-632-7
Pubchem	996
DrugBank	DB03255
SMILES	C1=CC=C(C=C1)O
Chemical-physical properties
Density (g/cm 3 , in c.s.)	1.06
Acid dissociation constant at 293 K	1.29 × 10 −10
Solubility in water	84 g/l a 293 K
Melting temperature	40,8 °C (314 K)
Boiling temperature	181,8 °C (455 K)
Steam voltage (PA) at 323 k	350
Thermochimic properties
D f H 0 (kJ · times −1 )	−165,1
S 0 m (J·K −1 mol −1 )	144
C 0 p,m (J·K −1 mol −1 )	127.4
Toxicological properties
DL 50 (mg/kg)	530 mg/kg rat (OS)
Safety indications
Flame point	81 °C (354 K)
Explosion limits	1,3 – 9,5% vol.
Self -cenition temperature	595 °C (868 K)
Chemical risk symbols
danger
Frasi h	301 – 311 – 314 – 331 – 341 – 373
Tips P	280 – 302+352 – 301+330+331 – 305+351+338 – 309+310 [first]
Change data on wikidata · Manual

The phenol It is an aromatic compound derived from benzene containing a hydrogenic group (-oh) directly linked to the benzene ring. This compound belongs to the class of the phenols, which groups the compounds that have one or more oxidriles linked to an aromatic ring.

Its chemical formula is c ₆ H ₅ OH. It must not be confused with the benzil alcohol (c ₆ H ₅ CH ₂ OH).

Pure, it presents itself in the form of white crystals, which due to oxidation due to the oxygen of the air tend to take a yellow or pink color over time. It melts well in water (84 g/l) and even better in ethanol and chloroform.

A solution of 50 g/l in water has a pH about 5. It is a very weak acid, its constant of acid dissociation at 20 ° C is 1.29 × 10 ⁻¹⁰ .

Although they own an obs-down group (-oh), phenols do not behave like alcohols. In fact, the phenols are more acidic than alcohols, because the negative charge of the anion (phenoxide) which is formed by dissociation of hydrogen of the oxom group is stabilized by resonance, which disperses the electric charge over the entire aromatic ring. The -oh group is usually purified through the use of strong bases such as the hydroxides of the metals of the first and second group (mainly Nah and Koh).

From the point of view of chemical reactivity, phenol undergoes very easily reactions of electrophilic replacement in positions for It is vegetable garden (the -oh group as a replacement on benzene is in fact defined as a group activating as it makes the ring more reactive than that of benzene and oriental vegetable garden).

Essay [ change | Modifica Wikitesto ]

Fenol in aqueous solution is identified by the addition of a few drops of ferric chloride; Blue coloring is obtained.

Industry, phenol is mainly synthesized by exploiting the cumne trial. Phenol is prepared by splitting, called disproportion, in an acid environment for sulfuric acid (100 ppm) of the hydroperoxide of Cumne (CHP), ^[2] Very unstable product (thermolable) that is obtained by compressed air oxidation in the basic environment of the isopropilbenzene (Cumne), a process from which acetone and acetopenone is also obtained, a substance used in cosmetics. Another way to the production of phenol is the alkaline fusion.

Cumene can be obtained simply and above all economically for benzene alkiing.

Cumene is an unstable hydrocarbon that reacts rapidly with the atmospheric oxygen oxidizing cumne to hydroperoxide. This type of oxidation is made easy by the fact that the main radical intermediate is a radical cumile not only tertiary but also benzilic, therefore extremely stable.

Hydroperoxide can then be treated with sulfuric acid to give phenol and acetone.

Initially known as “Phoenician acid”, it was summarized in 1860 and initially used as a deodorant and disinfectant for sewers.

Industry [ change | Modifica Wikitesto ]

About two thirds of Phenol production is used to produce plastic precursors. ^[3] The partial hydrogenation of Fenol produces Ciceasanone, a precursor of the nylon.

Fenol is a very common raw material in the production of dyes, herbicides, drugs – one of the best known is aspirin – and synthetic resins. One of the first was the Bachelite, obtained for the polymerization of phenol with formaldehyde.

Phenol is used as a reagent in chemical industry mainly for the production of bisfenol A, phenolic resins and caprictate. ^[4]

Fenol is a component of the industrial winterers used in the aeronautical industry for the removal of epoxy, polyurethane coatings and other resistant chemical coatings.

Medicine [ change | Modifica Wikitesto ]

Fenol has been widely used as an antiseptic; Its use was introduced in 1865 by the Scottish doctor Lister, professor of surgery in Glasgow, as an antiseptic on an exposed fracture, ^[5] but already experimented by doctor Enrico Bottini in 1862 in the surgery department of the Maggiore hospital in Novara ^[6] . Thus was born the practice of anti -Seepsi in surgery, followed subsequently by the practice of the Exepsi. Phenol acts on the bacterial cell, causing the protein component of the wall, causing their destruction. In practice, phenol physically damages the cell wall, altering its permeability in a lethal way.

Fenol was systematically and abundantly used in the disinfection of the operating rooms, surgical tools, the hands and cups of the sanitary ware, to the point that the lanes of the hospitals took the characteristic and pungent smell of phenol. From the early 1900s to the 70s it was used in the production of carbolical soap.

Only in recent years, phenol has been used in the outpatient surgical intervention called lateral lamectomy for phenness, which destroys the lateral matrix of the hallux nails to avoid the recurrence of the incarnated nail. Phenol is also used as a preservative in some vaccines. ^[7]

The phenol spray, containing 1.4% of phenol as an active ingredient, is used in medicine to relieve sore throat. ^[8] Phenol is also the active ingredient of some oral analgesics used to treat pharyngitis on a symptomatic level. ^[9]

Cosmetics [ change | Modifica Wikitesto ]

The ability of the high concentration of Fenolo aqueous solutions to cause burns to the skin is exploited in cosmetics in the production of preparations capable of removing the surface layers of the skin. Fenol derivatives are used in the preparation of cosmetics, including solar filters, ^[ten] Hair dyes, prepared to lighten the skin, and exfoliating. ^[11]

However, due to safety problems, the use of phenol is prohibited in cosmetic products in the European Union ^[twelfth] And in Canada. ^[13]

Phenol and its vapors are corrosive for the eyes, the skin and the respiratory tract. ^[14] The corrosive effect on the skin and mucous membranes is due to its ability to react with proteins. ^[3] The repeated or prolonged contact of the skin with phenol can cause dermatitis or second and third degree burns. ^[15] The inhalation of phenol vapors can cause pulmonary edema. ^[14] It can also cause harmful effects on the central nervous system and on the heart, causing arrhythmia, convulsions and coma. ^[16] The exposure repeated to phenol can also have harmful effects on the liver and the kidneys. ^[17] There is no evidence that phenol causes cancer in humans. ^[18] Fenol toxicity can also be due to the formation of Fenpossilic radicals. ^[19]

Since phenol is absorbed by the skin in relatively short times, in addition to burns systemic poisoning may occur. ^[3] The poisoning quickly leads to the paralysis of the central nervous system and a massive drop in body temperature. The LD ₅₀ For oral toxicity it is less than 500 mg / kg for dogs, rabbits and mice; while the minimum lethal human dose is 140 mg / kg. ^[3] The fatal dose for ingestion is between 1 and 32 g. ^[18]

Chemical burns on the skin can be decontaminated by washing with polyetilenglicle, ^[20] isopropyl alcohol, ^[21] Or even abundant water. ^[22] Removal of contaminated clothing is required, and an immediate hospital hospitalization for large burns.

Phenol causes an increased risk of abortion and a low birth weight, an indication of a delay in development in uterus. ^[23]

The word phenol is used to refer to any compound that contains an aromatic ring to six members, linked directly to a obsidrilic group (-Oh). Therefore, phenols are a class of organic compounds of which phenol is the simplest member.

Phenol can react as acid and be converted into their respective salts, the “molled”.

Phenol can react as an alcohol and form, with carboxylic acids, the foreign correspondents.

Fenol was discovered in 1834 by Friedlieb Ferdinand Runge, who extracted it (in impure form) from the carbon tar. Runge called the Fenol “Karbolsäure” (carolic acid). The carbon tar has remained the primary source until the development of the petrochemical industry.

In 1841, the French chemist Auguste Laurent obtained phenol in pure form. ^[24] In 1836 Augustte Laurent coined the name “Pène” for benzene; This is the root of the word “phenol” and “phenile”. In 1843, the French chemist Charles Gerhardt coined the name “Fenolo”. ^[25]

The antiseptic properties of phenol were used by Sir Joseph Lister (1827-1912) in its pioneering antiseptic surgery technique. ^[5] Lister I hypothesize that to avoid infections the wounds should be cleaned thoroughly. Initially he used gauze imbavute of Fenolo, who were however irritating for the wounds. ^[26] Thus was born the practice of anti -Seepsi in surgery, followed subsequently by the practice of the Exepsi.

Fenol was also used as a compound to perform death sentences. ^[27] In particular, phenol was used in Nazi extermination during the Second World War. ^[28] Fenol injections were administered to thousands of people in the concentration camps, especially in Auschwitz. The execution of the injections was carried out by doctors and their assistants; Initially the phenol was introduced by intravenous, usually in the arm, but subsequently the injections were performed directly in the heart of the victim in order to cause a faster and almost instantaneous death, within 15 seconds. This system was introduced in the initial stages, starting from 1941 in Auschwitz, where from 30 to 60 people were killed every day in this mode. One of Auschwitz’s most famous prisoners to be killed with an injection of Fenolo was Massimiliano Maria Kolbe, a Franciscan friar who voluntarily underwent three weeks of hunger and dehydration instead of another prisoner. He was then killed by the Nazis in order to make more place in the isolation cell, ^[27] And for this reason, Saint by Pope John Paul II declared in 1982. In addition to Father Kolbe, he also remembers the killing in the concentration camp of Dachau, through injection of Fenol, of Father Tito Brandsma, a Dutch presbyter, fervent opponent of the national socialist regime. Father Brandsma was declared blessed by Pope John Paul II in 1985 and canonized in 2022 by Pope Francis.

The use of the fenice acid on the hands is one of the possible scientific explanations to the phenomenon of stigmate, as supposed by Sergio Luzzatto in his biography of Padre Pio ^[29] .

• ( IN ) Klaus Weissle, Hans-Jepngege Arpe, Chalet R. Lindley, Industrial organic chemistry , 4ª ed., wiley-vch, 2003, pp. 10-1 349-363, ISBN 3-527-30578-5
• Uri Zoller, Paul Sosis, Handbook of Detergents, Part F: Production , CRC Press, 2008, ISBN 0-8247-0349-9.