In what areas of production is benzene used and symptoms of poisoning with it. aromatic hydrocarbons

Benzene is an important organic chemical compound with the chemical formula C 6 H 6 . The benzene molecule consists of 6 carbon atoms connected in a ring with 1 hydrogen atom attached to each of them. Because it contains only carbon and hydrogen atoms, benzene is classified as a hydrocarbon.

Benzene is a natural component of crude oil and is one of the elemental petrochemicals. Due to the cyclic continuous pi bond between carbon atoms, benzene is classified as an aromatic hydrocarbon, the second is [n]-annulene (-anulene). It is sometimes abbreviated as Ph-H. Benzene is a colorless and flammable liquid with a sweet odor and is responsible for the odor around petrol stations. It is used primarily as a precursor in the production of more complex chemicals such as ethylbenzene and cumene, from which billions of kilograms are produced. Since benzene has a high octane number, it is important component gasoline.

Because benzene is a human carcinogen, most non-industrial uses are limited.

Structure of benzene

X-ray diffraction shows that all six carbon-carbon bonds in benzene are the same length, at 140 picometres (pm). The C-C bonds are longer than a double bond (135 µm) but shorter than a single bond (147 µm). This intermediate distance is consistent with electron delocalization: electrons for C-C connections distributed equally between each of the six carbon atoms. Benzene has 6 hydrogen atoms, fewer than the corresponding parent alkane, hexane. The molecule is flat. The MO description includes the formation of three delocalized π orbitals spanning all six carbons, while the VB description includes a superposition of resonant structures. It is likely that this stability contributes to specific molecular and chemical properties, known as aromaticity. To accurately reflect the nature of the bond, benzene is often depicted with a circle within the hexagonal structure of the carbon atoms.

Benzene derivatives occur frequently enough as a component of organic molecules that the Unicode Consortium has isolated in the Technical Block the symbol with the code U+232C to represent it with three double bonds and U+23E3 for the delocalized version.

Benzene derivatives

Many important chemical compounds derived from benzene by replacing one or more of its hydrogen atoms with another functional group. Examples of simple benzene derivatives are phenol, toluene and aniline, abbreviated PhOH, PhMe and PhNH 2 respectively. Linking benzene rings gives biphenyl, C 6 H 5 -C 6 H 5 . Further loss of hydrogen yields "condensed" aromatics such as naphthalene and anthracene. The limit of the fusion process is the hydrogen allotrope of carbon, graphite.

In heterocycles, the carbon atoms in the benzene ring are replaced by other elements. The most important variations contain nitrogen. Replacing one CH with N gives the pyridine compound, C 5 H 5 N. Although benzene and pyridine are structurally related, benzene cannot be converted to pyridine. Replacing the second CH-N bond gives, depending on the location of the second N, pyridazine, pyrimidine, and pyrazine.

Benzene production

Four chemical processes contribute to industrial production benzene: catalytic reforming, toluene hydrodealkylation, toluene disproportionation and steam cracking. According to the ATSDR Benzene Toxicology Profile, between 1978 and 1981, catalytic reformats accounted for approximately 44-50% of total US benzene production.

catalytic reforming

In catalytic reforming, a mixture of hydrocarbons with a boiling point between 60-200°C is mixed with hydrogen gas and then subjected to bifunctional platinum chloride or rhenium chloride at a temperature of 500-525°C and pressures of 8 to 50 atm. Under these conditions, aliphatic hydrocarbons form rings and lose hydrogen to become aromatic hydrocarbons. The aromatic reaction products are then separated from the reaction mixture (reformed) by extraction with any of several solvents, including diethylene glycol or sulfolane, and then benzene is separated from other aromatic compounds by distillation. The stage of extraction of aromatic compounds from the reformate is designed to obtain aromatic compounds with the smallest non-aromatic components. The recovery of aromatics commonly referred to as BTX (benzene, toluene and xylene isomers) includes such extraction and distillation steps. There are many licensed processes available to extract aromatics.

Similar to this catalytic reforming, UOP and BP have commercialized the method from LPG (mainly propane and butane) to aromatics.

Toluene hydrodealkylation

Toluene hydrodealkylation converts toluene to benzene. In this hydrogen-intensive process, toluene is mixed with hydrogen, then passed through a catalyst based on chromium, molybdenum or platinum oxide at 500-600°C and a pressure of 40-60 atm. Sometimes higher temperatures are used instead of a catalyst (in a similar state of reaction). Under these conditions, toluene undergoes dealkylation to benzene and methane:

C 6 H 5 CH 3 + H 2 → C 6 H 6 + CH 4

This irreversible reaction is accompanied by an equilibrium side reaction that produces biphenyl (aka diphenyl) at a higher temperature:

2С 6 H 6 ⇌ H 2+C6H5-C6H 5

If the feed stream contains many non-aromatic components (paraffins or naphthenes), they are likely to decompose into lower hydrocarbons such as methane, which increases hydrogen consumption.

The typical yield of the reaction is greater than 95%. Sometimes xylenes and heavier aromatics are used instead of toluene with similar efficiency.

This is often referred to as a "targeted" methodology for benzene production compared to conventional BTX (benzene-toluene-xylene) extraction processes.

Tolunes dispersion

If the chemical complex has similar requirements for both benzene and xylene, then toluene disproportionation (TDP) may be an attractive alternative to toluene hydrodealkylation. Broadly speaking, 2 toluene molecules react and the methyl groups are rearranged from one toluene molecule to another, producing one benzene molecule and one xylene molecule.

Considering that the demand for paraxylene (p-xylene) substantially exceeds the demand for other xylene isomers, a refinement of the TDP process called selective TDP (STDP) can be used. In this process, the xylene stream exiting the TDP unit is approximately 90% paraxylene. In some existing catalyst systems, even the ratio of benzene to xylenes decreases (more xylenes) when the demand for xylenes is higher.

steam cracking

Steam cracking is a process for producing ethylene and other alkenes from aliphatic hydrocarbons. Depending on the feedstock used to produce olefins, steam cracking can produce a benzene-enriched liquid by-product called pyrolysis gasoline. Pyrolysis gasoline can be blended with other hydrocarbons as a gasoline additive or sent through an extraction process to recover BTX aromatics (benzene, toluene and xylenes).

Other Methods

Despite the lack of commercial value, there are many other routes to benzene. For example, phenol and halobenzenes can be reduced with metals. Benzoic acid and its salts are decarboxylated with benzene. Through the reaction, the combination of diazonium with the anion of hypophosphoric acid gives benzene. Trimerization of acetylene gives benzene.

Benzene reactions

The most common benzene reactions involve substitution of a proton by other groups. Electrophilic aromatic substitution is a common method for benzene derivatization. Benzene is sufficiently nucleophilic that it undergoes substitution with acyl ions and alkyl carbocations to give substituted derivatives.

Electrophilic aromatic substitution of benzene

The most common example of this reaction is the ethylation of benzene.

Friedel-Crafts acylation with benzene acetyl chloride

In 1999, about 24,700,000 tons of benzene were produced. Very instructive, but of less industrial importance, is the Friedel-Crafts alkylation of benzene (and many other aromatic rings) using an alkyl halide in the presence of a strong Lewis acid catalyst. Similarly, the Friedel-Crafts acylation is a related example of electrophilic aromatic substitution. The reaction involves the acylation of benzene (or many other aromatic rings) with an acyl chloride using a strong Lewis acid catalyst such as aluminum chloride or iron(III) chloride.

Sulfonation, chlorination, nitration

Using electrophilic aromatic substitution, many functional groups are introduced into the benzene structure. The sulfonation of benzene involves the use of oleum, a mixture of sulfuric acid and sulfur trioxide. Sulfonated benzene derivatives are useful detergents. When nitrated, benzene reacts with nitronium ions (NO 2 +), which is a strong electrophile obtained by combining sulfuric and nitric acids. Nitrobenzene is a precursor of aniline. Chlorination is achieved with chlorine to produce chlorobenzene in the presence of a catalyst such as aluminum trichloride.

hydrogenation

BENZENE, the simplest representative of aromatic hydrocarbons, C 6 H 6 . It was discovered in 1825 by M. Faraday, who isolated benzene from liquid condensate of lighting gas; obtained in pure form in 1833 by E. Mitcherlich by pyrolysis of the calcium salt of benzoic acid. In 1865, F. A. Kekule proposed a formula for the structure of benzene with alternating single and double bonds.

Benzene is a colorless liquid with a mild odor; t pl 5.53 °С, t bp 80.1 °С. Practically insoluble in water, miscible in all proportions with most non-polar organic solvents; dissolves fats, rubbers, resins; forms azeotropic mixtures with water and alcohols. In the benzene molecule, carbon atoms in the state of sp 2 hybridization form a flat, regular hexagon with a distance between carbon atoms of 139 pm, and all atoms of the cycle participate in the formation of a single π -electronic system. The benzene molecule satisfies all criteria for aromaticity.

Benzene has the chemical properties of aromatic compounds. When benzene is nitrated with a mixture of concentrated HNO 3 and H 2 SO 4, nitrobenzene is formed, which can be reduced to aniline. Benzene is sulfonated with concentrated H 2 SO 4 to benzene sulfonic acids; alkylated with alkyl halides to alkylbenzenes and acylated (in the presence of an AlCl 3 catalyst) with carboxylic acid chlorides to aromatic fatty ketones (see the Friedel-Crafts article for the reaction). When benzene is alkylated with ethylene, ethylbenzene is formed, from which styrene is obtained in industry; similarly, cumene is formed from benzene and propylene - the starting product for the production of phenol and acetone. When benzene is oxidized with atmospheric oxygen when heated in the presence of a catalyst, maleic anhydride is obtained. Benzene hardly enters into addition reactions. So, only during the photochemical chlorination of benzene, hexachlorocyclohexane is formed, which is used as an insecticide. During catalytic hydrogenation, benzene is converted into cyclohexane, the starting product in the production of ε-caprolactam.

Benzene is found in the coke oven gas formed during pyrolysis hard coal. The main amount of benzene is obtained by reforming at 470-540 °C of the oil fraction, which boils away at 62-85 °C. Benzene is the most important raw material of the chemical industry, it is used in the production of explosives, fragrant, medicinal substances, pesticides, dyes, polymeric materials, as well as a solvent and extractant in the production of varnishes, paints, etc.

Mixtures of benzene with air (1.5-8% benzene by volume) are explosive. Benzene is toxic and can cause acute and chronic poisoning.

Lit .: Sokolov V. 3., Kharlampovich GD Production and use of aromatic hydrocarbons. M., 1980; General organic chemistry. M., 1981. T. 1; Lebedev NN Chemistry and technology of basic organic and petrochemical synthesis. 4th ed. M., 1988.

Benzene(also benzene)- the first representative of the homologous series of aromatic hydrocarbons, the molecular formula is C 6 H 6. A colorless volatile liquid with a characteristic odor. First obtained by Michael Faraday from whale oil pyrolysis condensate in 1825.

Industrially, benzene was extracted from coal tar fractions, but since the middle of the 20th century, almost the entire industrial volume of benzene has been produced by the dehydrogenation of petroleum feedstocks. Benzene has valuable properties as a solvent, but due to its high toxicity and carcinogenicity, such use has so far been very limited. This compound is a raw material for industrial organic synthesis, more than two thirds of benzene is used for the production of cyclohexane, cumene and ethylbenzene.

Research history

Benzene is the first arena discovered by man. In its pure form, it was isolated by Michael Faraday by distillation of crystallization from luminous gas, is a product of the high-temperature decomposition of whale oil, and was used in street lamps. Then it was installed relative density its vapors and the quantitative ratio between the atoms of the elements that make up its composition, based on these data, Faraday calculated the empirical formula - C 2 H 2. The error in the formula was made due to the fact that at that time it was believed that the atomic mass of carbon is 6 a.o.m. 1834 Mitscherlich isolated benezene by dry distillation of benzoic acid with lime, he established the correct empirical formula (C 6 H 6) and called this compound "gasoline" from benzoic acid. However, Liebig suggested using the name benzene, the ending of which is taken from the German word. Öl- butter. The modern name "benzene" is recommended for use by IUPAC due to the fact that the suffix -ol corresponds to alcohols. 1860 Kekule named benzene and other compounds with similar properties aromatic, because most of them had a pleasant smell.

On the basis of the correct empirical formula of benzene, writing the structural formulas of organic compounds has not yet been accepted in chemistry. However, even after structural formulas were proposed for many aliphatic hydrocarbons, it was more difficult to do this for benzene: the formula C 6 H 6 indicated that this compound belonged to unsaturated hydrocarbons, however, benzene, unlike alkenes and alkynes, enters into substitution reactions better than accession. In 1865, Kekule proposed a structural formula for benzene in the form of a six-membered ring with three double bonds alternating with single ones. It is widely known that the idea of ​​the cyclic structure of benzene came to Kekula when he dreamed of a snake biting its own tail. Later descriptions of the dream mention six monkeys holding each other by their hind legs. In fact, the cyclic structure of beneznu was first published in his book by the Austrian chemist Josef Loschmidt in 1861 and Kekule saw this edition.

Kekule's formulas could not explain some of the features of benzene, such as the fact that there were no two different isomers of 1,2-dimethylbenzene. In 1872, the scientist published an article in which he noted that although the existence of two different valence isomers can be assumed for benzene, the real compound is the average between these two due to the oscillation (transition) of double bonds. However, even such an addition could not explain the difference between benzene and known unsaturated hydrocarbons, so other scientists continued to offer alternative versions of the structure of this substance. Among them are the Dewar formulas of 1867 and the prismatic structure of Ladenburg (1869). It is now known that such compounds can indeed be synthesized; they are valence isomers of benzene.

Of the explanations of the properties of benzene proposed for the discovery of the nature of the covalent bond, the closest to the modern is the theory of "partial valencies" (from lat. Partialis- partial) proposed by Thiele in 1899. According to it, carbon atoms in unsaturated compounds have partial free valences, which in the benzene molecule “close” with each other, as a result of which the difference between single and double bonds disappears. The creation of the theory of a covalent bond made it possible to better understand the structure of benezenu, in 1926 Ingold suggested that in the molecule of this compound the electrons of π-bonds are shifted to simple σ-bonds, as a result of which they do not exist in an isolated state, but are aligned between single ones. Later, Linus Pauling, based on quantum mechanical concepts, proposed to consider that there are no separate π-bonds in the benzene molecule, and all their electrons are combined into a continuous π-cloud.

IN scientific literature both the Pauling formula and the Kekule formula are used to designate benzene, although the latter do not correctly reflect the structure of this molecule.

Physical Properties

Benzene is a colorless liquid with a peculiar smell. Density - 0.88 g / cm³. At a temperature of 80.1 ° C, it boils, and at 5.5 ° C it freezes into a white crystalline mass.

Due to its symmetry, benzene is a non-polar substance, therefore it does not dissolve in water, however, it forms an azeotropic mixture with it (91.17 wt%) with a boiling point of 69.25 ° C. It is miscible with most non-polar solvents in any ratio, itself is good solvent for many organic matter.

In the ultraviolet region of the absorption spectrum, it manifests itself in a number of fine-structure bands with a distance of 5–6 nm between them (it is most intense in the range of 170–120 nm and less in the range of 270–240 nm).

Structure

The molecular formula is C 6 H 6. X-ray methods have established that the benzene molecule has the shape of a flat hexagon with carbon atoms at the vertices. Everything C-C connections have the same length, which is 0.140 nm. This is more than that of a double (0.134 nm) bond and less than that of a single (0.154 nm) bond. Benzene is a non-polar compound with zero dipole moment (μ).

All carbon atoms in the benzene molecule are in the state sp 2 hybridization. The three hybrid orbitals are at 120°, forming C-C and C-H σ bonds. non-hybridney p-orbitals located perpendicular to the plane of the molecule, forming a continuous electronic ring. From the point of view of the theory of valence bonds, this ring can be considered as a superposition of two resonance structures of an imaginary 1,3,5-cyclohexatriene with isolated C=C double bonds. From the point of view of the theory of molecular orbitals, it can be considered as the result of delocalization along six carbon atoms of three π-orbitals of double C=C bonds. The consequence of delocalization is the lower free energy (greater stability) of benzene compared to 1,3,5-cyclohexatriene. This difference in energy is called conjugation, delocalization, or resonance energy. It can be calculated based on the heats of hydrogenation of cyclohexene and benzene:

• the heat of hydrogenation to cyclohexene is 120 kJ/mol;
• then the expected heat of hydrogenation of 1,3,5-cyclohexatriene should be about 3 × 120 kJ/mol = 360 kJ/mol;
• in fact, the heat of hydrogenation of benzene is 208 kJ/mol;
• then the conjugation energy is 360 kJ/mol - 208 kJ/mol = 152 kJ/mol.

The formation of a continuous π-cloud containing six electrons gives the benzene molecule the so-called aromatic character. The carbon skeleton of a benzene molecule with this type of bond is called the benzene ring, or the benzene core.

Chemical properties

Due to the significant stability of the π-cloud for benzene, in contrast to non-aromatic unsaturated hydrocarbons, characteristic substitution reactions, and not additions, since they should lead to loss of aromaticity, however, addition reactions can also occur under fairly severe conditions. The substitution occurs by an electrophilic mechanism. Benzene also enters into oxidation reactions.

Electrophilic substitution reactions

Benzene enters into electrophilic substitution reactions that occur according to the following mechanism: at the first stage, a π-complex is formed between the electrophile (in the form of a cation or a highly polarized molecule E σ + -Nu σ-) and the benzene molecule, as a result of overlapping LUMO Electrophile with HOMO ( π-cloud) of benzene. After this a couple p-electrons leaves the conjugated benzene ring and participates in the formation of a σ-bond with an electrophile, thus the π-complex turns into a σ-complex or Welland intermediate. This intermediate has a positive charge and is devoid of aromatic character, which makes it less stable than the aromatic ring, which is usually quickly converted into by proton elimination (this step occurs through another intermediate π-complex).

Alkylation and acylation according to Friedel-Crafts

Alkylation of benzene is carried out with alkyl halides, alkenes and alcohols, acylation - carboxylic acids, acid halides and anhydrides, both types of reactions catalyzed by Lewis acids. These reactions are named after their discoverers Charles Friedel and James Crafts.

The role of a catalyst in this type of reaction is that it reacts with an alkylating or acylating reagent and provides the formation of a carbocation or polarized complex. For example, the interaction of Chloromethane and aluminum chloride forms a complex with enhanced electrophilicity of the carbon atom:

An example of an alkylation reaction would be the ethylation of benzene with chloroethane.

However, in industry, ethylbenzene is more often obtained by reaction with ethylene, which also takes place in the presence of alumina, phosphoric or sulfuric acid:

The products of benzene acylation reactions are aromatic ketones. An example would be the reaction with acetyl chloride, the product of which is methyl aryl ketone:

Halogenation

Unlike unsaturated hydrocarbons, benzene does NOT decolorize bromine water. But it is characterized by halogenation reactions occurring by the mechanism of electrophilic substitution in the presence of Lewis acids. For example, when interacting with bromine, bromobenzene is formed:

Nitration

The nitration reaction characteristic of benzene uses a nitration mixture that consists of concentrated nitric acid and concentrated sulfuric acid as dewatering agents. In this reaction, nitrobenzene is formed, which is a precursor in the synthesis of aniline

Sulfonation

When benzene is exposed to concentrated sulfuric acid, it is sulfonated with the formation of benzosulfonic acid, it can be a precursor in the synthesis of phenol:

Addition reactions

Benzene also enters into addition reactions, but is much more difficult than in substitution reactions. At the same time, it exhibits the properties of unsaturated hydrocarbons. So, in the presence of a nickel catalyst and when heated, the hydrogenation of benzene occurs with the formation of cyclohexane:

In this case, hydrogen atoms are attached to the benzene molecule due to the breaking of double bonds. Benzene also enters into the addition reaction of one, two or three chlorine molecules. This reaction occurs by a free radical mechanism for the formation of chlorine radicals requires ultraviolet light (achieved by irradiation with a mercury-quartz lamp). The complete addition product is hexachlorocyclohexane:

Oxidation reactions

In air, benzene burns strongly with a soot flame, since the carbon content in it is significant. The mixture of a pair of benzene with air is explosive. Due to its aromatic nature, benzene is resistant to oxidizing agents: it is not oxidized by potassium permanganate solution and nitric acid. In the presence of a catalyst, vanadium(V) oxide reacts with molecular oxygen, resulting in the formation of maleic anhydride:

Benzene is also oxidized by ozone, a reaction historically used to determine its structure.

Receiving and production

Today, there are several fundamental different ways benzene production.

1. Coking coal. This process was historically the first and served as the main source of benzene until World War II. Recently, the proportion of benzene obtained by this method is less than 10%. It should be added that benzene obtained from coal tar contains a significant amount of thiophene, which makes such benzene a raw material unsuitable for a number of technological processes.
2. Catalytic reforming (aromaising) of gasoline fractions of oil. This process is the main source of benzene in the US. IN Western Europe, Russia and Japan in this way receive 40-60% of the total amount of the compound. In this process, in addition to benzene, toluene and xylenes are formed. Considering that toluene is formed in quantities exceeding the demand for it, it is also partially processed into: benzene - by the hydrodealkylation method; a mixture of benzene and xylenes - by disproportionation;
3. Pyrolysis of gasoline and heavier oil fractions. Up to 50% of benzene is produced by this method. Along with benzene, toluene and xylenes are formed. In some cases, this entire fraction is sent to the dealkylation step, where both toluene and xylenes are converted to benzene.
4. acetylene trimerization

When passing acetylene at 600 °C over activated carbon benzene and other aromatic hydrocarbons are formed with a good yield (reaction of N. D. Zelinsky):

3C 2 H 2 → C 6 H 6

Application

Benzene is an important raw material for the chemical industry. Large quantities of it go to obtain nitrobenzene, which, according to the reaction of M. M. Zinin, is reduced to aniline:

In technology, this reaction is carried out by exposing benzene to hydrochloric acid in the presence of iron shavings. Iron, reacting with acid, forms hydrogen, which, at the time of isolation, restores nitrobenzene. The most organic dyes and pharmaceuticals are synthesized from aniline. Significant amounts of benzene are used for the synthesis of phenol, which is used in the production of phenol-formaldehyde resins. Hexachlorocyclohexane, obtained from benzene (the reaction is given above), called hexachloran, is used in agriculture as one of the most effective means to kill insects. In addition, benzene is used for the synthesis of many other organic compounds and as a solvent.

	Receipt	Substance	Application
+ Cl 2 / AlCl 3 → C 6 H 5 Cl	+ Cl 2 / AlCl 3 → 1,4-dichlorobenzene	1,4-dichlorobenzene	Insecticide
+ NaOH/Cu → Phenol	Phenol	Solvent, organic synthesis reagent, plastics, dyes, drugs, explosives
+ H 2 SO 4 → Benzosulfonic acid (C 6 H 5 -SO 2 OH) + NaOH → Phenol
+ Propene (CH 3 -CH \u003d CH 2) → Kumenes (C 6 H 5 -CH (CH 3) 2) + O 2 → Hydroperoxide Kumenes (C 6 H 5 -C (CH 3) 2 -OOH) → Phenol + acetone
+ HNO 3 → nitrobenzene + 6H → aniline	Aniline (C 6 H 5 -NH 2)	Dyes, drugs
+ H 2 / Ni → Cyclohexane → Caprolactam	Caprolactam	Synthetic fibers
+ O 2 / V 2 O 5 → Maleic acid → Maleic anhydride	Maleic anhydride	Polyesters
+ Ethylene (CH 2 \u003d CH 2) → Ethylbenzene (C 6 H 5 -CH 2 -CH 3) + ZnO → erasure (C 6 H 5 -CH \u003d CH 2) + H 2	Styrene	Plastics, synthetic rubbers
+ HOSO 2 Cl → Benzosulfanyl chloride (C 6 H 5 -SO 2 Cl) → Benzosulfanilamide	Benzosulfanilamide	Medicines, dyes

Below are the usage percentages

• About 50% of benzene is converted to ethylbenzene (alkylation of benzene with ethylene)
• about 25% of benzene is converted to cumene (alkylation of benzene with propylene)
• about 10-15% of benzene is hydrogenated to cyclohexane;
• about 10% of benzene is spent on the production of nitrobenzene;
• 2 - 3% of benzene is converted into linear alkylbenzenes;
• approximately 1% of benzene is used to synthesize chlorobenzene.

In much smaller quantities, benzene is used for the synthesis of other compounds. Rarely and in extreme cases, due to its high toxicity, benzene is used as a solvent. In addition, benzene is part of gasoline. Due to its high toxicity, its content is limited to the introduction of up to 5% by new standards.

Benzene homologues

Benzene, like other hydrocarbons, forms its own homologous series, has the general formula C n H 2n-6. Benzene homologues can be considered as products of substitution of one or more hydrogen atoms in the benzene molecule by various hydrocarbon radicals forming side chains.

The simplest homologue of benzene is methylbenzene - the product of substitution of a hydrogen atom in a benzene molecule by a methyl group - CH 3

Methylbenzene, technically called toluene, is a colorless liquid with a characteristic odor. Boiling point 110.6 ° C. Density 0.867 g / cm In terms of its chemical properties, methylbenzene, or toluene, like other benzene homologues, is very close to benzene. So, under the action of concentrated nitric acid, in the presence of sulfuric acid, it easily lends itself to nitration with the formation of trinitrotoluene, a highly explosive substance.

Methylbenzene (toluene) is extracted from coal tar and coke oven gas along with benzene and then separated by fractional distillation. Methylbenzene, or toluene, is used mainly for the production of explosives - trinitrotoluene, which is also called TNT and tol. In addition, toluene serves as a raw material for the production of dyes and other organic products.

Related videos

. Benzene plays an extremely important role in various chemical industries. industry. Benzene was first discovered in light fractions of coal tar by Faraday in 1825. The special properties of benzene and its derivatives were expressed in the structure formula proposed in 1865 by Kekule, in the form of a closed chain of six carbon atoms, in which there is one hydrogen atom . However, such a structure is not entirely consistent with the properties of various substances obtained from benzene, and therefore, over time, various researchers have made some modifications to the formula for the structure of benzene regarding Ch. arr. distribution of affinity forces within the carbon cycle. The main source of benzene is the products obtained during the processing of coal into coke and lighting gas. Recently, attempts have been made to obtain benzene from oil by its pyrogenetic decomposition, but they have not yet led to the development of sufficiently cost-effective methods. From the gases of coke ovens, which contain the bulk of benzene, it is extracted by various solvents or adsorbed by solids. Usually, a fraction of coal tar is used for dissolution, which in the range of 200-300 ° gives at least 80% of the distillate; sometimes, instead of coal oil, oil distillates, known as solar oil, are used. At good oil up to 98% of all benzene contained in the gas can be extracted.

Coke oven gas, having passed through refrigerators, tar separators and ammonia washers, having a temperature not exceeding 20°C, enters the scrubber, where it is washed with absorbent oil that dissolves benzene. Scrubbers are high round towers, inside of which a nozzle is made, which promotes closer mixing of gas with absorption oil. Oil saturated with benzene with a content of the latter of about 3% is supplied for regeneration to column apparatus, where the so-called crude benzene, which has up to 65% pure benzene, is distilled off. The oil freed from benzene is cooled and goes back to the gas scrubber. Raw benzene contains big number various carbonaceous compounds and varies in composition. Fluctuations in the composition, depending on the nature of production, are visible from the following table:

In addition to these substances, crude benzene also contains naphthalene, cumene, thiotolene, phenol, cresols, pyridine, and coumarones. At the factories of Donbass, the content of pure benzene in the raw product averages about 52%. To obtain pure benzene, the crude product is subjected to purification and rectification. The first distillation gives 90% benzene, which then goes to purification and further distillation to obtain pure benzene. Purification consists in successive washing of benzene with a solution of alkali, acid and water. If benzene contains bases and phenols, then it is first washed with dilute sulfuric acid, which removes the bases, and the alkali then dissolves all acidic substances. Carbon disulphide, thiophene, unsaturated aliphatic hydrocarbons are removed by treatment with strong sulfuric acid 60-66 ° Vè, which sulfonates and tars all unsaturated and sulfur compounds, converting them into soluble and easily washed out substances with alkali. Cleaning is carried out in special apparatus - mixers, equipped inside with devices for mechanical mixing of the liquid in order to ensure the fastest and most complete cleaning possible. Benzene, freed from impurities and sulfur compounds (for this purpose it is necessary to resort to re-treatment with acid), enters the final distillation to obtain a pure product. Completely pure benzene is a colorless, transparent, easily mobile, highly flammable liquid that solidifies at 5.483° (according to a hydrogen thermometer) and boils at 80.08° (760 mm Hg). The specific gravity of benzene D 25 \u003d 0.87345, D 4 15.5 \u003d 0.8845, it changes with temperature; according to Kopp, v t \u003d 1 + 0.001171626t + 0.00000127755t 2 + 0.00000080648t 3 . The coefficient of refraction n D 8.2 = 1.50808. Specific volume at 20° - 0.67171. The specific heat of pure benzene, according to Treen (Tgehin) at 16.2 ° - 0.402, 20.2 ° - 0.412, 30.0 ° - 0.419, 42.8 ° - 0.429, 50.4 ° - 0.437, 58.1 ° - 0.449; specific heat commercial benzene, purified by freezing, at 18.3° - 0.414, 22.7° - 0.418, 31.8° - 0.425, 40.3° - 0.439; 52.0° - 0.452.

Heat of combustion at constant volume 10.014 Cal. Benzene at 22° is soluble in water in an amount of 0.082 volumes per 100 volumes of water. Water dissolves in benzene depending on temperature as follows (in %%):

Benzene is an excellent solvent for fats, resins, rubber and other organic compounds.

Chemical properties. Benzene is difficult to react with substances that interact with ethylene and its derivatives. In the presence of catalysts - nickel, palladium or platinum - benzene adds 6 hydrogen atoms and passes into hexohydrobenzene or hexamethylene. The hydrogen atoms of benzene can be replaced by halides to form the corresponding halogen derivatives. Strong sulfuric and nitric acids react with benzene to give the corresponding sulfo and nitro derivatives. Commercial grades of benzene are usually not pure benzene, but contain toluene and xylene in varying amounts. According to Kramer and Shpilker, the following grades of commercial benzene are distinguished (depending on the% content of substances in it that distils up to 100 °):

The fields of application of benzene are very diverse. Large quantities of benzene are currently used as an admixture in motor gasoline, which significantly improves the quality of the latter. In England, the National Benzol Association imposes the following requirements on motor benzene: specific gravity 0.870-0.885; during distillation, benzene should give up to 100 ° - 75%, 120 ° - 90%, 125 ° - 100%; its sulfur content should not exceed 0.4%; benzene must not contain water; degree of purification: when shaking 90 cm 3 of benzene with 10 cm 3 of 90% H 2 SO 4 for 5 minutes, the acid should turn into a color no darker than light brown; benzene should not contain acids, alkalis and hydrogen sulfide; should freeze at least -14 °.

Benzene is used as a solvent and for extraction purposes in various industries: for the preparation of varnishes and linoleum, for degreasing bones, for the extraction of wax and rosin, for dry cleaning of various materials. Benzene is one of the most commonly used solvents in rubber factories. It also serves as the starting material for the preparation of dyes, explosives and fragrances, pharmaceutical and photographic preparations. Huge quantities benzene are processed into nitro- and dinitrobenzene, from which aniline, nitroaniline and phenylenediamine are obtained by reduction - important products of the technology of organic substances that serve as Ch. as a starting material in the manufacture of a wide variety of aniline dyes. Mono- and disulfonic acids are prepared by sulfonation from benzene, which are further processed into phenol and resorcinol.

Before the war, the production of benzene in Russia was extremely poorly developed. With the outbreak of the war and, consequently, with an increase in the need for benzene, which was used to prepare various explosives, coke-benzene installations had to be hastily organized. The planned and successful development of the benzene industry began from the moment the Koksobenzene Joint-Stock Company was organized in the USSR, and at present the amount of benzene produced annually significantly exceeds the most productive years of the pre-war period.

Occupational benzene poisoning. Benzene is one of the most powerful professional poisons. Benzene poisoning of workers is possible: in coke-benzene production, during the distillation of coal tar; at chemical and pharmaceutical plants in the production of various aromatic substances; in the production processes of various organic paints; in the production of explosives; when extracting fats from bones and coconuts; at glue factories, where benzene is used as a solvent for resins, varnishes, fats, iodine, phosphorus and sulfur; in rubber production; in the manufacture of waterproof fabrics, linoleum, celluloid; when painting various items fast-drying paints and varnishes (in particular, airplane wings); during carburation of light and water gas; in chemical dye-houses and when degreasing fabrics, clothes, etc.; when servicing internal combustion engines, etc. Recently, in the West, many patented products containing benzene (varnishes, paints, compositions for cleaning various objects) have been produced under a variety of names and cause serious poisoning of workers.

Benzene penetrates into the body. way through the respiratory tract and through the lungs penetrates into the blood. However, benzene can also be absorbed through intact skin. Benzene is much more poisonous than gasoline (according to Leman and Kravkov, 4 times, according to Kon-Abrest, 10 times). The content in the air of 10 mg of benzene vapor per 1 liter (by volume 3-4 hours per 1000 hours) already causes discomfort; the presence of 20-30 mg of benzene in 1 liter of air usually causes loss of consciousness for several hours. Sometimes, however, even 0.001 by volume of benzene in the air caused death. In order to prevent the slow effect on workers of long-term inhalation of benzene vapors, their content in the working atmosphere should not be allowed to exceed 1:10,000, or approximately 0.25 mg / l (although, according to a special American commission that published its report in 1927 ., even under these conditions, the effects of benzene on the body cannot be completely avoided).

Benzene poisoning can be acute or chronic. In recent years, a number of deaths have been published in the medical literature, either immediately after a single inhalation of a significant amount of benzene vapor, or as a result of an acute illness after a short period of work in an atmosphere with a significant amount of benzene vapor in the air. Immediate death usually occurs when working in insufficiently ventilated tanks, tanks, etc. receptacles, as well as in case of rupture of vessels or pipes and in case of unnoticed malfunctions in the equipment. Serious diseases, often ending in death, usually occur when there is insufficient cubic capacity of the room, lack of ventilation, and especially at high room temperature. Acute poisoning, which does not end in immediate death, when inhaled in large doses, causes severe changes in the central nervous system: trembling, convulsions, severe blanching, sensitivity disorders, fainting, and often malignant anemia (affecting especially women). Milder cases cause dizziness, headache, tinnitus, and vomiting. For the most part, a state of intoxication and general euphoria soon sets in, as a result of which the poisoned person loses the correct perception of what is happening, does not notice the danger, does not leave the place where the vapors are released, and, in the absence of outside help, may become a victim of further poisoning. In chronic poisoning, which lasts for months and even years, in addition to the nervous system, the circulatory and hematopoietic organs are primarily affected, as a result of which, in addition to severe anemia, numerous small hemorrhages appear, both in the mucous membranes of various internal organs and in the skin. As a result, the so-called "spotted disease" and scurvy-like changes in the mucous membrane of the mouth. Women usually have severe uterine bleeding. Recovery is rare and even in favorable cases is very delayed. Such a heavy effect of benzene is explained by the fact that it is a strong poison that acts on the protoplasm of all cells of the body and on the main oxidative processes. Measures to prevent benzene poisoning are basically the same as for gasoline poisoning. It must be added that, wherever possible, benzene should be replaced by the much less poisonous xylene, toluene, carbon tetrachloride, or gasoline, and women should not be allowed to work with benzene.

toxic, carcinogenic Data is based on standard conditions (25 °C, 100 kPa) unless otherwise noted.

History

For the first time, benzene-containing mixtures resulting from the distillation of coal tar were described by the German chemist Johann Glauber in the book Furni novi philosophici, published in 1651. Benzene as an individual substance was described by Michael Faraday, who isolated this substance in 1825 from the condensate of light gas obtained by coking coal. Soon, in 1833, benzene was obtained - during the dry distillation of the calcium salt of benzoic acid - and the German physical chemist Eilhard Mitscherlich. It was after this preparation that the substance began to be called benzene.

By the 1860s, it was known that the ratio of the number of carbon atoms and hydrogen atoms in a benzene molecule was similar to that of acetylene, and the empirical formula for them is C n H n. The study of benzene was seriously taken up by the German chemist Friedrich August Kekule, who in 1865 managed to propose the correct - cyclic formula of this compound. There is a story that F. Kekule imagined benzene in the form of a snake of six carbon atoms. The idea of ​​​​the cyclical connection came to him in a dream, when an imaginary snake bit its tail. Friedrich Kekule managed at that time to most fully describe the properties of benzene.

Physical Properties

Colorless liquid with a peculiar pungent odor. Melting point = 5.5 °C, Boiling point = 80.1 °C, Density = 0.879 g/cm³, Molar mass = 78.11 g/mol. Like unsaturated hydrocarbons, benzene burns with a highly sooty flame. It forms explosive mixtures with air, mixes well with ether, gasoline and other organic solvents, forms an azeotropic mixture with water with a boiling point of 69.25 ° C (91% benzene). Solubility in water 1.79 g/l (at 25 °C).

Chemical properties

Benzene is characterized by substitution reactions - benzene reacts with alkenes, chloroalkanes, halogens, nitric and sulfuric acids. Benzene ring cleavage reactions take place under harsh conditions (temperature, pressure).

• Interaction with chlorine and bromine in the presence of a catalyst to form chlorobenzene (electrophilic substitution reaction):

$\backslash mathsf(C\_6H\_6\; +\; Cl\_2\; \backslash xrightarrow(FeCl\_3)\; C\_6H\_5Cl\; +\; HCl)$

• In the absence of a catalyst, when heated or illuminated, a radical addition reaction occurs with the formation of a mixture of hexachlorocyclohexane isomers

$\backslash mathsf(C\_6H\_6\; +\; 3Cl\_2\; \backslash xrightarrow(T,\; h\backslash nu)\; C\_6H\_6Cl\_6)$

• Interaction with halogenated alkanes (benzene alkylation, Friedel-Crafts reaction) to form alkylbenzenes:

$\backslash mathsf(C\_6H\_6\; +\; C\_2H\_5Br\; \backslash xrightarrow(FeBr\_3)\; C\_6H\_5C\_2H\_5\; +\; HBr)$

• Sulfonation and nitration reactions (electrophilic substitution):

$\backslash mathsf(C\_6H\_6\; +\; HNO\_3\; \backslash xrightarrow(H\_2SO\_4)\; C\_6H\_5NO\_2\; +\; H\_2O)$ $\backslash mathsf(C\_6H\_6\; +\; H\_2SO\_4\; \backslash rightarrow\; C\_6H\_5SO\_3H\; +\; H\_2O)$

• Burning benzene:

$\backslash mathsf(2C\_6H\_6\; +\; 15O\_2\; \backslash rightarrow\; 12CO\_2\; +\; 6H\_2O)$

Structure

By composition, benzene belongs to unsaturated hydrocarbons (homologous series C n H2 n−6), but unlike hydrocarbons of the ethylene series, C 2 H 4, exhibits properties inherent in unsaturated hydrocarbons (they are characterized by addition reactions), only under harsh conditions, but benzene is more prone to substitution reactions. This "behavior" of benzene is explained by its special structure: the presence of atoms in the same plane and the presence of a conjugated 6π-electron cloud in the structure. Modern representation about the electronic nature of bonds in benzene is based on the hypothesis of Linus Pauling, who proposed to depict the benzene molecule as a hexagon with an inscribed circle, thereby emphasizing the absence of fixed double bonds and the presence of a single electron cloud covering all six carbon atoms of the cycle.

Production

Today, there are several fundamental various ways benzene production.

Application

A significant part of the resulting benzene is used for the synthesis of other products:

• about 50% of benzene is converted to ethylbenzene (alkylation of benzene with ethylene);
• about 25% of benzene is converted to cumene (alkylation of benzene with propylene);
• approximately 10-15% benzene is hydrogenated to cyclohexane;
• about 10% of benzene is spent on the production of nitrobenzene;
• 2-3% of benzene is converted into linear alkylbenzenes;
• approximately 1% of benzene is used to synthesize chlorobenzene.

In much smaller quantities, benzene is used for the synthesis of some other compounds. Occasionally and in extreme cases, due to its high toxicity, benzene is used as a solvent.

In addition, benzene is a constituent of gasoline. In the 1920s - 1930s, benzene was added de into straight-run gasoline to increase its octane rating, but by the 1940s such blends could not compete with high-octane gasolines. Due to the high toxicity, the content of benzene in fuel is limited by modern standards to the introduction of up to 1%.

Biological action

With a short inhalation of benzene vapor, no immediate poisoning occurs, therefore, until recently, the procedure for working with benzene was not particularly regulated.

In large doses, benzene causes nausea and dizziness, and in some severe cases, poisoning can be fatal. Euphoria is often the first sign of benzene poisoning. Benzene vapor can penetrate intact skin. Liquid benzene is quite irritating to the skin. If the human body is exposed to long-term exposure to benzene in small quantities, the consequences can also be very serious.

Benzene and substance abuse

Benzene has an intoxicating effect on a person and can lead to drug addiction.

Acute poisoning

At very high concentrations - almost instantaneous loss of consciousness and death within a few minutes. The color of the face is cyanotic, the mucous membranes are often cherry red. At lower concentrations - excitation, similar to alcohol, then drowsiness, general weakness, dizziness, nausea, vomiting, headache, loss of consciousness. Muscle twitches are also observed, which can turn into tonic convulsions. The pupils are often dilated and unresponsive to light. Breathing is first quickened, then slowed down. Body temperature drops sharply. Pulse quickened, small filling. The blood pressure is lowered. Cases of severe cardiac arrhythmia are known.

After severe poisoning, which does not lead directly to death, long-term health disorders are sometimes observed: pleurisy, catarrhs ​​of the upper respiratory tract, diseases of the cornea and retina, liver damage, heart disorders, etc. A case of vasomotor neurosis with swelling of the face and extremities, sensitivity disorders and convulsions a short time after acute poisoning with benzene vapor is described. Sometimes death occurs some time after poisoning.

chronic poisoning

In severe cases, there are: headaches, extreme fatigue, shortness of breath, dizziness, weakness, nervousness, drowsiness or insomnia, indigestion, nausea, sometimes vomiting, lack of appetite, increased urination, menstruation, persistent bleeding from the oral mucosa, especially gums, often develops. , and nose, lasting for hours and even days. Sometimes persistent bleeding occurs after tooth extraction. Numerous small hemorrhages in the skin. Blood in stools, uterine bleeding, retinal hemorrhage. Usually, it is the bleeding, and often the accompanying fever (temperature up to 40 ° and above) that brings the poisoned to the hospital. In such cases, the prognosis is always serious. The cause of death is sometimes secondary infections: there are cases of gangrenous inflammation of the periosteum and necrosis of the jaw, severe ulcerative inflammation of the gums, general sepsis with septic endometritis.

Sometimes, with severe poisoning, symptoms of nervous diseases develop: increased tendon reflexes, bilateral clonus, positive Babinsky symptom, deep sensitivity disorder, pseudo-tabetic disorders with paresthesias, ataxia, paraplegia and motor disorders (signs of damage to the posterior columns of the spinal cord and pyramidal tract).

The most typical changes in the blood. The number of erythrocytes is usually sharply reduced, down to 1-2 million and below. The content of hemoglobin also falls sharply, sometimes up to 10%. The color index in some cases is low, sometimes close to normal, and sometimes high (especially with severe anemia). Anisocytosis and poikilocytosis, basophilic puncture and the appearance of nuclear erythrocytes, an increase in the number of reticulocytes and the volume of erythrocytes are noted. A sharp decrease in the number of leukocytes is more typical. Sometimes initially leukocytosis, quickly followed by leukopenia, accelerated ESR. Changes in the blood do not develop simultaneously. Most often, the leukopoietic system is affected earlier, later thrombocytopenia joins. The defeat of erythroblastic function often occurs even later. In the future, a characteristic picture of severe poisoning may develop - aplastic anemia.

The action of benzene on biomembranes

Benzene is an effective solubilizer of biomembranes; it quickly dissolves non-polar tails of lipids, mainly cholesterol, which is part of membranes. The solubilization process is limited by the concentration of benzene, the more it is, the faster this process proceeds. In this case, a rupture of the double lipid layer occurs, which leads to complete destruction of the membrane and subsequent cell apoptosis (during the destruction of biomembranes, activation of receptors that trigger cell apoptosis occurs).

Action on the skin

With frequent contact of hands with benzene, dry skin, cracks, itching, redness (usually between the fingers), swelling, and millet-like blisters are observed. Sometimes, due to skin lesions, workers are forced to quit their jobs.

The maximum allowable concentration is 5 mg/m 3 .

see also

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Notes

Literature

• Benzene // Great Soviet Encyclopedia: [in 30 volumes] / ch. ed. A. M. Prokhorov. - 3rd ed. - M. : Soviet Encyclopedia, 1969-1978.
• // Encyclopedic Dictionary of Brockhaus and Efron: in 86 volumes (82 volumes and 4 additional). - St. Petersburg. , 1890-1907.
• Encyclopedic Dictionary of a Young Chemist / Comp. V. A. Kritsman, V. V. Stanzo. - Pedagogy. - M ., 1982. - 368 p.
• O. S. Gabrielyan, I. G. Ostroumov. Handbook of a chemistry teacher grade 10. - M .: Bustard, 2010.
• Omelyanenko L. M. and Senkevich N. A. Clinic and prevention of benzene poisoning. - M., 1957.

Alkanes Alkenes Alkynes dienes Other unsaturated Cycloalkanes aromatic Polycyclic

An excerpt characterizing Benzene

“I don’t know… Your Excellency… There were no people, Your Excellency.”
- You could take it from cover!
That there was no cover, Tushin did not say this, although it was the absolute truth. He was afraid to let the other boss down by this and silently, with fixed eyes, looked straight into Bagration's face, just as a student who has gone astray looks into the examiner's eyes.
The silence was quite long. Prince Bagration, apparently not wanting to be strict, did not have anything to say; the rest did not dare to intervene in the conversation. Prince Andrei looked at Tushin from under his brows, and his fingers moved nervously.
“Your Excellency,” Prince Andrei interrupted the silence with his harsh voice, “you deigned to send me to Captain Tushin’s battery. I was there and found two-thirds of the men and horses killed, two guns mangled, and no cover.
Prince Bagration and Tushin were now equally stubbornly looking at Bolkonsky, who spoke with restraint and excitement.
“And if, Your Excellency, let me express my opinion,” he continued, “the success of the day we owe most of all to the action of this battery and the heroic stamina of Captain Tushin with his company,” said Prince Andrei and, without waiting for an answer, immediately got up and walked away from the table.
Prince Bagration looked at Tushin and, apparently not wanting to show distrust of Bolkonsky's sharp judgment and, at the same time, feeling unable to fully believe him, bowed his head and told Tushin that he could go. Prince Andrew followed him.
“Thank you, you helped me out, my dear,” Tushin told him.
Prince Andrei glanced at Tushin and, without saying anything, walked away from him. Prince Andrei was sad and hard. It was all so strange, so unlike what he had hoped.

"Who are they? Why are they? What do they need? And when will it all end?" thought Rostov, looking at the changing shadows before him. The pain in my arm was getting worse and worse. Sleep became irresistible, red circles jumped in my eyes, and the impression of these voices and these faces and the feeling of loneliness merged with the feeling of pain. It was they, these soldiers, wounded and unwounded, it was they who pressed, and weighed, and twisted the veins, and burned the meat in his broken arm and shoulder. To get rid of them, he closed his eyes.
He forgot himself for one minute, but during this short interval of oblivion he dreamed of countless objects: he saw his mother and her big white hand, saw Sonya's thin shoulders, Natasha's eyes and laughter, and Denisov with his voice and mustache, and Telyanin, and his whole history with Telyanin and Bogdanych. This whole story was one and the same, that this soldier with a sharp voice, and this and that whole story, and this and that soldier so painfully, relentlessly held, crushed, and all in one direction pulled his hand. He tried to move away from them, but they did not let go of his hair, not even for a second on his shoulder. It wouldn't hurt, it would be great if they didn't pull it; but it was impossible to get rid of them.
He opened his eyes and looked up. The black canopy of night hung a yard above the light of the coals. Powders of falling snow flew in this light. Tushin did not return, the doctor did not come. He was alone, only some kind of soldier was now sitting naked on the other side of the fire and warming his thin yellow body.
"No one wants me! thought Rostov. - No one to help or pity. And I was once at home, strong, cheerful, beloved. He sighed and groaned involuntarily.
- What hurts? - asked the soldier, shaking his shirt over the fire, and without waiting for an answer, grunting, added: - You never know they spoiled the people in a day - passion!
Rostov did not listen to the soldier. He looked at the snowflakes fluttering over the fire and recalled the Russian winter with a warm, bright house, a fluffy fur coat, a fast sleigh, a healthy body, and with all the love and care of the family. "And why did I come here!" he thought.
The next day, the French did not resume their attacks, and the remnant of the Bagration detachment joined Kutuzov's army.

Prince Vasily did not consider his plans. He even less thought to do evil to people in order to gain an advantage. He was only a man of the world who had succeeded in the world and made a habit out of this success. Depending on the circumstances, according to his rapprochement with people, he constantly drew up various plans and considerations, in which he himself did not fully realize, but which constituted the whole interest of his life. Not one or two such plans and considerations happened to him in use, but dozens, of which some were just beginning to appear to him, others were achieved, and still others were destroyed. He did not say to himself, for example: “This man is now in power, I must gain his trust and friendship and through him arrange for a lump-sum allowance,” or he did not say to himself: “Here, Pierre is rich, I must lure him to marry his daughter and borrow the 40,000 I need”; but a man in strength met him, and at that very moment instinct told him that this man could be useful, and Prince Vasily approached him and at the first opportunity, without preparation, instinctively, flattered, became familiar, talked about that, about what was needed.
Pierre was at his fingertips in Moscow, and Prince Vasily arranged for him to be appointed to the Junker Chamber, which then equaled the rank of State Councilor, and insisted that the young man go with him to Petersburg and stay at his house. As if absent-mindedly and at the same time with undoubted confidence that this should be so, Prince Vasily did everything that was necessary in order to marry Pierre to his daughter. If Prince Vasily had thought ahead of his plans, he could not have had such naturalness in his manners and such simplicity and familiarity in dealing with all people placed above and below himself. Something constantly attracted him to people stronger or richer than him, and he was gifted with the rare art of seizing precisely that moment when it was necessary and possible to use people.
Pierre, having suddenly become rich and Count Bezukhy, after recent loneliness and carelessness, felt himself surrounded and busy to such an extent that he only managed to remain alone in bed with himself. He had to sign papers, deal with government offices, the meaning of which he did not have a clear idea, ask the general manager about something, go to an estate near Moscow and receive many people who previously did not even want to know about its existence, but now would be offended and upset if he did not want to see them. All these diverse faces - businessmen, relatives, acquaintances - were all equally well, affectionately disposed towards the young heir; all of them, obviously and undoubtedly, were convinced of the high merits of Pierre. Incessantly he heard the words: “With your extraordinary kindness”, or “with your beautiful heart”, or “you yourself are so pure, count ...”, or “if he were as smart as you”, etc., so he he sincerely began to believe in his extraordinary kindness and his extraordinary intelligence, all the more so since it always seemed to him, in the depths of his soul, that he was really very kind and very smart. Even people who were previously angry and obviously hostile became tender and loving with him. Such an angry eldest of the princesses, with a long waist, with her hair smoothed like a doll's, came to Pierre's room after the funeral. Lowering her eyes and constantly flashing, she told him that she was very sorry for the misunderstandings that had been between them and that now she did not feel entitled to ask anything, except for permission, after the stroke that had befallen her, to stay for several weeks in the house that she loved so much and where made so many sacrifices. She could not help but cry at these words. Touched by the fact that this statue-like princess could have changed so much, Pierre took her by the hand and asked for forgiveness, without knowing why. From that day on, the princess began to knit a striped scarf for Pierre and completely changed towards him.
“Do it for her, mon cher; all the same, she suffered a lot from the deceased, ”Prince Vasily told him, letting him sign some kind of paper in favor of the princess.
Prince Vasily decided that this bone, a bill of 30 tons, should still be thrown to the poor princess so that it would not occur to her to talk about the participation of Prince Vasily in the case of the mosaic portfolio. Pierre signed the bill, and since then the princess has become even kinder. younger sisters they also became affectionate towards him, especially the youngest, pretty, with a mole, often embarrassed Pierre with her smiles and embarrassment at the sight of him.
It seemed so natural to Pierre that everyone loved him, it would seem so unnatural if someone did not love him, that he could not help but believe in the sincerity of the people around him. Moreover, he did not have time to ask himself about the sincerity or insincerity of these people. He constantly had no time, he constantly felt himself in a state of meek and cheerful intoxication. He felt himself to be the center of some important general movement; felt that something was constantly expected of him; that, if he didn’t do this, he would upset many and deprive them of what they expected, but if he did this and that, everything would be fine - and he did what was demanded of him, but this something good still remained ahead.
More than anyone else in this first time, both Pierre's affairs and himself were mastered by Prince Vasily. Since the death of Count Earless, he has not let go of Pierre. Prince Vasily looked like a man weighed down by deeds, tired, exhausted, but out of compassion he could not finally leave this helpless young man, the son of his friend, apres tout, [in the end] and with such a huge fortune to the mercy of fate and rogues. In those few days that he spent in Moscow after the death of Count Bezukhy, he called Pierre to him or came to him himself and ordered him what needed to be done, in such a tone of fatigue and confidence, as if he always said:
"Vous savez, que je suis accable d" affaires et que ce n "est que par pure charite, que je m" occupe de vous, et puis vous savez bien, que ce que je vous propose est la seule chose faisable. You know, I'm overwhelmed with business; but it would be ruthless to leave you like that; of course, what I'm telling you is the only possible one.]
“Well, my friend, we’re leaving tomorrow, finally,” he once said to him, closing his eyes, running his fingers over his elbow and in such a tone as if what he was saying had been decided a long time ago between them and could not have been decided otherwise.
- Tomorrow we are going, I give you a place in my carriage. I am very happy. Here we have everything important. And I should have for a long time. Here's what I got from the Chancellor. I asked him about you, and you are enrolled in the diplomatic corps and made chamber junker. Now the diplomatic road is open to you.
Despite all the strength of the tone of fatigue and the confidence with which these words were uttered, Pierre, who had been thinking about his career for so long, wanted to object. But Prince Vasily interrupted him in that cooing, bass tone, which ruled out the possibility of interrupting his speech and which he used in case of need for extreme persuasion.
- Mais, mon cher, [But, my dear,] I did it for myself, for my conscience, and there is nothing to thank me for. No one ever complained that he was too loved; and then, you are free, even if you quit tomorrow. Here you will see everything yourself in St. Petersburg. And it's time for you to move away from these terrible memories. Prince Vasily sighed. Yes, yes, my soul. And let my valet ride in your carriage. Oh yes, I had forgotten, ”Prince Vasily added,“ you know, mon cher, that we had accounts with the deceased, so I received from Ryazan and will leave it: you don’t need it. We agree with you.
What Prince Vasily called from "Ryazan" was several thousand dues, which Prince Vasily left with himself.
In St. Petersburg, as well as in Moscow, an atmosphere of tender, loving people surrounded Pierre. He could not refuse the place or, rather, the title (because he did nothing) that Prince Vasily brought him, and there were so many acquaintances, calls and social activities that Pierre, even more than in Moscow, experienced a feeling of haziness, haste and everything that comes, but does not happen any good.
From his former bachelor society, many were not in St. Petersburg. The Guard went on the march. Dolokhov was demoted, Anatole was in the army, in the provinces, Prince Andrei was abroad, and therefore Pierre could neither spend the nights, as he used to like to spend them, nor occasionally take his soul in a friendly conversation with an older respected friend. All the time it was held at dinners, balls, and mainly with Prince Vasily - in the company of the fat princess, his wife, and the beautiful Helen.
Anna Pavlovna Scherer, like others, showed Pierre the change that had taken place in the public view of him.
Previously, Pierre, in the presence of Anna Pavlovna, constantly felt that what he was saying was indecent, tactless, not what was needed; that his speeches, which seem clever to him, while he is preparing them in his imagination, become stupid as soon as he speaks out loud, and that, on the contrary, the most stupid speeches of Hippolytus come out smart and sweet. Now everything he said came out charmant. Even if Anna Pavlovna did not say this, he saw that she wanted to say it, and she only, in respect of his modesty, refrained from doing so.
At the beginning of the winter from 1805 to 1806, Pierre received from Anna Pavlovna the usual pink note with an invitation, in which was added: "Vous trouverez chez moi la belle Helene, qu "on ne se lasse jamais de voir." [I will have a beautiful Helen that you never get tired of admiring.]
Reading this place, Pierre for the first time felt that some kind of connection had formed between him and Helene, recognized by other people, and this thought at the same time frightened him, as if an obligation was imposed on him that he could not keep, and together he liked it, as an amusing assumption.
Anna Pavlovna's evening was the same as the first, only the novelty that Anna Pavlovna treated her guests was now not Mortemar, but a diplomat who had arrived from Berlin and brought the latest details about the stay of Emperor Alexander in Potsdam and how the two highest friend swore there in an inseparable alliance to defend a just cause against the enemy of the human race. Pierre was received by Anna Pavlovna with a tinge of sadness, which, obviously, related to the fresh loss that had befallen young man, to the death of Count Bezukhy (everyone constantly considered it a duty to assure Pierre that he was very saddened by the death of his father, whom he hardly knew) - and sadness is exactly the same as that highest sadness that was expressed when mentioning the august Empress Maria Feodorovna. Pierre felt flattered by this. Anna Pavlovna, with her usual art, arranged circles in her drawing room. A large circle, where Prince Vasily and the generals were, used a diplomat. The other circle was at the tea table. Pierre wanted to join the first, but Anna Pavlovna, who was in an irritated state of a commander on the battlefield, when thousands of new brilliant thoughts come that you barely have time to put into practice, Anna Pavlovna, seeing Pierre, touched him on the sleeve.
- Attendez, j "ai des vues sur vous pour ce soir. [I have views of you this evening.] She looked at Helen and smiled at her. - Ma bonne Helene, il faut, que vous soyez charitable pour ma pauvre tante , qui a une adoration pour vous. Allez lui tenir compagnie pour 10 minutes. it was boring, here is a dear count who will not refuse to follow you.
The beauty went to her aunt, but Pierre Anna Pavlovna still kept her beside her, showing a look as if she still had to make the last necessary order.
- Isn't she amazing? - she said to Pierre, pointing to the departing majestic beauty. - Et quelle tenue! [And how she keeps herself!] For such a young girl, and such tact, such masterful demeanor! It comes from the heart! Happy will be the one whose it will be! With her, the most non-secular husband will involuntarily occupy the most brilliant place in the world. Is not it? I just wanted to know your opinion, - and Anna Pavlovna let Pierre go.
Pierre sincerely answered Anna Pavlovna in the affirmative to her question about Helen's art of keeping herself. If he ever thought of Helen, he thought precisely of her beauty and of her unusual calm ability to be silently worthy in the world.
Auntie received two young people into her corner, but it seemed she wished to hide her adoration for Helen and wished to express her fear of Anna Pavlovna more. She looked at her niece, as if asking what she should do with these people. Moving away from them, Anna Pavlovna again touched Pierre's sleeve with her finger and said:
- J "espere, que vous ne direz plus qu" on s "ennuie chez moi, [I hope you won't say another time that I'm bored,] - and looked at Helen.
Helen smiled with a look that said that she did not allow the possibility that anyone could see her and not be admired. The aunt cleared her throat, swallowed her saliva, and said in French that she was very glad to see Helen; then she turned to Pierre with the same greeting and with the same mine. In the middle of a boring and stumbling conversation, Helen looked back at Pierre and smiled at him with that smile, clear, beautiful, with which she smiled at everyone. Pierre was so accustomed to this smile, it expressed so little for him that he paid no attention to it. Auntie was talking at that time about the collection of snuff boxes that Pierre's late father, Count Bezukhy, had, and showed her snuff box. Princess Helen asked to see the portrait of her aunt's husband, which was made on this snuffbox.
“That’s right, it was done by Vines,” said Pierre, naming a well-known miniaturist, bending down to the table to pick up a snuffbox, and listening to the conversation at another table.
He got up, wanting to go around, but the aunt brought the snuffbox right over Helen, behind her. Helen leaned forward to make room and looked around smiling. She was, as always at the evenings, in a dress that was very open, in the fashion of the time, in front and behind. Her bust, which always seemed marble to Pierre, was at such a close distance from his eyes that with his short-sighted eyes he involuntarily distinguished the lively beauty of her shoulders and neck, and so close to his lips that he had to bend down a little to touch her. He could hear the warmth of her body, the smell of perfume, and the creak of her corset as she moved. He did not see her marble beauty, which was one with her dress, he saw and felt all the charm of her body, which was covered only by clothes. And, having once seen this, he could not see otherwise, how we cannot return to the deceit once explained.