Higher organic chemistry. Organic chemistry

Organic chemistry - branch of chemistry that studies carbon compounds, their structure, properties , methods of synthesis, as well as the laws of their transformations. Organic compounds are compounds of carbon with other elements (mainly H, N, O, S, P, Si, Ge, etc.).

The unique ability of carbon atoms to bond with each other, forming chains of different lengths, cyclic structures of different sizes, framework compounds, compounds with many elements, different in composition and structure, determines the diversity of organic compounds. To date, the number of known organic compounds far exceeds 10 million and increases every year by 250-300 thousand. The world around us is built mainly from organic compounds, these include: food, clothing, fuel, dyes, medicines, detergents, materials for a wide variety of branches of technology and the national economy. Organic compounds play a key role in the existence of living organisms.

At the intersection of organic chemistry with inorganic chemistry, biochemistry and medicine, the chemistry of metal- and organoelement compounds, bioorganic and medicinal chemistry, and the chemistry of high-molecular compounds arose.

The main method of organic chemistry is synthesis. Organic chemistry studies not only compounds obtained from plant and animal sources (natural substances), but mainly compounds created artificially through laboratory and industrial synthesis.

History of the development of organic chemistry

Methods for obtaining various organic substances have been known since ancient times. Thus, the Egyptians and Romans used dyes of plant origin - indigo and alizarin. Many peoples possessed the secrets of producing alcoholic beverages and vinegar from sugar- and starch-containing raw materials.

During the Middle Ages, practically nothing was added to this knowledge; some progress began only in the 16th and 17th centuries (the period of iatrochemistry), when new organic compounds were isolated through the distillation of plant products. In 1769-1785 K.V. Scheele isolated several organic acids: malic, tartaric, citric, gallic, lactic and oxalic. In 1773 G.F. Ruel isolated urea from human urine. The substances isolated from animal and plant materials had much in common with each other, but differed from inorganic compounds. This is how the term “Organic chemistry” arose - a branch of chemistry that studies substances isolated from organisms (definition J.Ya. Berzelius, 1807). At the same time, it was believed that these substances could only be obtained in living organisms thanks to the “vital force”.

It is generally accepted that organic chemistry as a science appeared in 1828, when F. Wöhler first obtained an organic substance - urea - as a result of evaporation of an aqueous solution of an inorganic substance - ammonium cyanate (NH 4 OCN). Further experimental work demonstrated undeniable arguments for the inconsistency of the “life force” theory. For example, A. Kolbe synthesized acetic acid M. Berthelot obtained methane from H 2 S and CS 2, and A.M. Butlerov synthesized sugary substances from formaldehyde.

In the middle of the 19th century. The rapid development of synthetic organic chemistry continues, the first industrial production of organic substances is being created ( A. Hoffman, W. Perkin Sr.- synthetic dyes, fuchsin, cyanine and aza dyes). Improving open N.N. Zinin(1842) method for the synthesis of aniline served as the basis for the creation of the aniline dye industry. In the laboratory A. Bayer natural dyes were synthesized - indigo, alizarin, indigoid, xanthene and anthraquinone.

An important stage in the development of theoretical organic chemistry was the development F. Kekule theory of valence in 1857, as well as the classical theory of chemical structure A.M. Butlerov in 1861, according to which atoms in molecules are connected in accordance with their valency, the chemical and physical properties of compounds are determined by the nature and number of atoms included in them, as well as the type of bonds and the mutual influence of directly unbonded atoms. In 1865 F. Kekule proposed the structural formula of benzene, which became one of the most important discoveries in organic chemistry. V.V. Markovnikov And A.M. Zaitsev formulated a number of rules that for the first time linked the direction of organic reactions with the structure of the substances entering into them. In 1875 Van't Hoff And Le Bel proposed a tetrahedral model of the carbon atom, according to which the valencies of carbon are directed towards the vertices of the tetrahedron, in the center of which the carbon atom is located. Based on this model, combined with experimental studies I. Vislicenus(!873), which showed the identity of the structural formulas of (+)-lactic acid (from sour milk) and (±)-lactic acid, stereochemistry arose - the science of the three-dimensional orientation of atoms in molecules, which predicted the presence of 4 different substituents at carbon atom (chiral structures) the possibility of the existence of spatially mirror isomers (antipodes or enantiomers).

In 1917 Lewis proposed to consider chemical bonding using electron pairs.

In 1931 Hückel applied quantum theory to explain the properties of non-benzenoid aromatic systems, which founded a new direction in organic chemistry - quantum chemistry. This served as an impetus for further intensive development of quantum chemical methods, in particular the method of molecular orbitals. The stage of penetration of orbital concepts into organic chemistry was discovered by the theory of resonance L. Pauling(1931-1933) and further works K. Fukui, R. Woodward And R. Hoffman about the role of frontier orbitals in determining the direction of chemical reactions.

Mid 20th century characterized by a particularly rapid development of organic synthesis. This was determined by the discovery of fundamental processes, such as the production of olefins using ylides ( G. Wittig, 1954), diene synthesis ( O. Diels And K. Alder, 1928), hydroboration of unsaturated compounds ( G. Brown, 1959), nucleotide synthesis and gene synthesis ( A. Todd, H. Koran). Advances in the chemistry of metal-organic compounds are largely due to the work of A.N. Nesmeyanova And G.A. Razuvaeva. In 1951, the synthesis of ferrocene was carried out, the “sandwich” structure of which was established R. Woodward And J. Wilkinson laid the foundation for the chemistry of metallocene compounds and the organic chemistry of transition metals in general.

In 20-30 A.E. Arbuzov creates the foundations of the chemistry of organophosphorus compounds, which subsequently led to the discovery of new types of physiologically active compounds, complexons, etc.

In 60-80 Ch. Pedersen, D. Kram And J.M. Linen are developing the chemistry of crown ethers, cryptands and other related structures capable of forming strong molecular complexes, and thereby approaching the most important problem of “molecular recognition”.

Modern organic chemistry continues its rapid development. New reagents, fundamentally new synthetic methods and techniques, new catalysts are introduced into the practice of organic synthesis, and previously unknown organic structures are synthesized. The search for organic new biologically active compounds is constantly underway. Many more problems of organic chemistry are awaiting solution, for example, a detailed establishment of the structure-property relationship (including biological activity), the establishment of the structure and stereodirectional synthesis of complex natural compounds, the development of new regio- and stereoselective synthetic methods, the search for new universal reagents and catalysts .

The interest of the world community in the development of organic chemistry was clearly demonstrated by the awarding of the Nobel Prize in Chemistry in 2010. R. Heku, A. Suzuki and E. Negishi for work on the use of palladium catalysts in organic synthesis for the formation of carbon-carbon bonds.

Classification of organic compounds

The classification is based on the structure of organic compounds. The basis for describing the structure is the structural formula.

Main classes of organic compounds

Hydrocarbons - compounds consisting only of carbon and hydrogen. They in turn are divided into:

Saturated- contain only single (σ-bonds) and do not contain multiple bonds;

Unsaturated- contain at least one double (π-bond) and/or triple bond;

Open chain(alicyclic);

Closed circuit(cyclic) - contain a cycle

These include alkanes, alkenes, alkynes, dienes, cycloalkanes, arenes

Compounds with heteroatoms in functional groups- compounds in which the carbon radical R is bonded to a functional group. Such compounds are classified according to the nature of the functional group:

Alcohol, phenols(contain hydroxyl group OH)

Ethers(contain the grouping R-O-R or R-O-R

Carbonyl compounds(contain the RR"C=O group), these include aldehydes, ketones, quinones.

Compounds containing a carboxyl group(COOH or COOR), these include carboxylic acids, esters

Element- and organometallic compounds

Heterocyclic compounds - contain heteroatoms as part of the ring. They differ in the nature of the cycle (saturated, aromatic), in the number of atoms in the cycle (three-, four-, five-, six-membered cycles, etc.), in the nature of the heteroatom, in the number of heteroatoms in the cycle. This determines the huge variety of known and annually synthesized compounds of this class. The chemistry of heterocycles represents one of the most fascinating and important areas of organic chemistry. Suffice it to say that more than 60% of drugs of synthetic and natural origin belong to various classes of heterocyclic compounds.

Natural compounds - compounds, as a rule, have a rather complex structure, often belonging to several classes of organic compounds. Among them are: amino acids, proteins, carbohydrates, alkaloids, terpenes, etc.

Polymers- substances with a very high molecular weight, consisting of periodically repeating fragments - monomers.

Structure of organic compounds

Organic molecules are mainly formed by covalent non-polar C-C bonds, or covalent polar bonds such as C-O, C-N, C-Hal. Polarity is explained by a shift in electron density towards the more electronegative atom. To describe the structure of organic compounds, chemists use the language of structural formulas of molecules, in which the bonds between individual atoms are designated using one (simple or single bond), two (double) or three (triple) valence primes. The concept of a valence prime, which has not lost its meaning to this day, was introduced into organic chemistry A. Cooper in 1858

The concept of hybridization of carbon atoms is very essential for understanding the structure of organic compounds. The carbon atom in the ground state has an electronic configuration of 1s 2 2s 2 2p 2, on the basis of which it is impossible to explain the inherent valency of 4 for carbon in its compounds and the existence of 4 identical bonds in alkanes directed to the vertices of the tetrahedron. Within the framework of the valence bond method, this contradiction is resolved by introducing the concept of hybridization. When excited, it is carried out s→p electron transition and the subsequent so-called sp- hybridization, and the energy of the hybridized orbitals is intermediate between the energies s- And p-orbitals. When bonds are formed in alkanes, three R-electrons interact with one s-electron ( sp 3-hybridization) and 4 identical orbitals arise, located at tetrahedral angles (109 about 28") to each other. The carbon atoms in alkenes are in sp 2-hybrid state: each carbon atom has three identical orbitals lying in the same plane at an angle of 120° to each other ( sp 2 orbitals), and the fourth ( R-orbital) is perpendicular to this plane. Overlapping R-orbitals of two carbon atoms form a double (π) bond. Carbon atoms bearing a triple bond are in sp- hybrid state.

Features of organic reactions

Inorganic reactions usually involve ions, and such reactions proceed quickly and to completion at room temperature. In organic reactions, covalent bonds often break and new ones are formed. Typically, these processes require special conditions: certain temperatures, reaction times, certain solvents, and often the presence of a catalyst. Usually, not one, but several reactions occur at once. Therefore, when depicting organic reactions, not equations are used, but diagrams without calculating stoichiometry. The yields of target substances in organic reactions often do not exceed 50%, and their isolation from the reaction mixture and purification require specific methods and techniques. To purify solids, recrystallization from specially selected solvents is usually used. Liquid substances are purified by distillation at atmospheric pressure or in vacuum (depending on the boiling point). To monitor the progress of reactions and separate complex reaction mixtures, various types of chromatography are used [thin-layer chromatography (TLC), preparative high-performance liquid chromatography (HPLC), etc.].

Reactions can occur very complexly and in several stages. Radicals R·, carbocations R+, carbanions R-, carbenes:СХ2, radical cations, radical anions and other active and unstable particles, usually living for a fraction of a second, can appear as intermediate compounds. A detailed description of all the transformations that occur at the molecular level during a reaction is called reaction mechanism. Based on the nature of the cleavage and formation of bonds, radical (homolytic) and ionic (heterolytic) processes are distinguished. According to the types of transformations, there are radical chain reactions, nucleophilic (aliphatic and aromatic) substitution reactions, elimination reactions, electrophilic addition, electrophilic substitution, condensation, cyclization, rearrangement processes, etc. Reactions are also classified according to the methods of their initiation (excitation ), their kinetic order (monomolecular, bimolecular, etc.).

Determination of the structure of organic compounds

Throughout the existence of organic chemistry as a science, the most important task has been to determine the structure of organic compounds. This means finding out which atoms are part of the structure, in what order and how these atoms are connected to each other and how they are located in space.

There are several methods for solving these problems.

• Elemental analysis consists in the fact that a substance is decomposed into simpler molecules, by the number of which one can determine the number of atoms that make up the compound. This method does not make it possible to establish the order of bonds between atoms. Often used only to confirm the proposed structure.
• Infrared spectroscopy (IR spectroscopy) and Raman spectroscopy (Raman spectroscopy). The method is based on the fact that the substance interacts with electromagnetic radiation (light) in the infrared range (absorption is observed in IR spectroscopy, and scattering of radiation is observed in Raman spectroscopy). This light, when absorbed, excites the vibrational and rotational levels of molecules. The reference data are the number, frequency and intensity of vibrations of the molecule associated with a change in the dipole moment (IR) or polarizability (PC). The method allows one to determine the presence of functional groups, and is also often used to confirm the identity of a substance with some already known substance by comparing their spectra.
• Mass spectrometry. A substance under certain conditions (electron impact, chemical ionization, etc.) turns into ions without loss of atoms (molecular ions) and with loss (fragmentation, fragment ions). The method makes it possible to determine the molecular mass of a substance, its isotopic composition, and sometimes the presence of functional groups. The nature of fragmentation allows us to draw some conclusions about the structural features and reconstruct the structure of the compound under study.
• Nuclear magnetic resonance (NMR) method is based on the interaction of nuclei that have their own magnetic moment (spin) and are placed in an external constant magnetic field (spin reorientation) with alternating electromagnetic radiation in the radio frequency range. NMR is one of the most important and informative methods for determining chemical structure. The method is also used to study the spatial structure and dynamics of molecules. Depending on the nuclei interacting with radiation, they distinguish, for example, the proton resonance method (PMR, 1 H NMR), which allows one to determine the position of hydrogen atoms in the molecule. The 19 F NMR method allows one to determine the presence and position of fluorine atoms. The 31 P NMR method provides information about the presence, valence state and position of phosphorus atoms in the molecule. The 13 C NMR method allows you to determine the number and types of carbon atoms; it is used to study the carbon skeleton of a molecule. Unlike the first three, the last method uses a minor isotope of the element, since the nucleus of the main isotope 12 C has zero spin and cannot be observed by NMR.
• Ultraviolet spectroscopy method (UV spectroscopy) or spectroscopy of electronic transitions. The method is based on the absorption of electromagnetic radiation in the ultraviolet and visible regions of the spectrum during the transition of electrons in a molecule from upper filled energy levels to vacant ones (excitation of the molecule). Most often used to determine the presence and characterization of conjugated π systems.
• Methods of analytical chemistry make it possible to determine the presence of certain functional groups by specific chemical (qualitative) reactions, the occurrence of which can be recorded visually (for example, the appearance or change of color) or using other methods. In addition to chemical methods of analysis, instrumental analytical methods such as chromatography (thin-layer, gas, liquid) are increasingly used in organic chemistry. Chromatography-mass spectrometry occupies a place of honor among them, allowing not only to assess the degree of purity of the resulting compounds, but also to obtain mass spectral information about the components of complex mixtures.
• Methods for studying the stereochemistry of organic compounds. Since the beginning of the 80s. The feasibility of developing a new direction in pharmacology and pharmacy related to the creation of enantiomerically pure drugs with an optimal balance of therapeutic efficacy and safety became obvious. Currently, approximately 15% of all synthesized pharmaceuticals are represented by pure enantiomers. This trend is reflected in the appearance in the scientific literature of recent years of the term chiral switch, which in Russian translation means “switching to chiral molecules.” In this regard, methods for establishing the absolute configuration of chiral organic molecules and determining their optical purity acquire special importance in organic chemistry. The main method for determining the absolute configuration should be X-ray diffraction analysis (XRD), and the optical purity should be chromatography on columns with a chiral stationary phase and the NMR method using special additional chiral reagents.

Relationship between organic chemistry and the chemical industry

The main method of organic chemistry - synthesis - closely links organic chemistry with the chemical industry. Based on the methods and developments of synthetic organic chemistry, small-scale (fine) organic synthesis arose, including the production of drugs, vitamins, enzymes, pheromones, liquid crystals, organic semiconductors, solar cells, etc. The development of large-scale (basic) organic synthesis is also based on the achievements of organic chemistry. The main organic synthesis includes the production of artificial fibers, plastics, processing of oil, gas and coal raw materials.

Recommended reading

• G.V. Bykov, History of organic chemistry, M.: Mir, 1976 (http://gen.lib/rus.ec/get?md5=29a9a3f2bdc78b44ad0bad2d9ab87b87)
• J. March, Organic chemistry: reactions, mechanisms and structure, in 4 volumes, M.: Mir, 1987
• F. Carey, R. Sandberg, Advanced course in organic chemistry, in 2 volumes, M.: Chemistry, 1981
• O.A. Reutov, A.L. Kurtz, K.P. Butin, Organic chemistry, in 4 parts, M.: “Binom, Laboratory of Knowledge”, 1999-2004. (http://edu.prometey.org./library/autor/7883.html)
• Chemical encyclopedia, ed. Knunyantsa, M.: “Big Russian Encyclopedia”, 1992.

Of the variety of chemical compounds, most (over four million) contain carbon. Almost all of them are organic substances. Organic compounds are found in nature, such as carbohydrates, proteins, vitamins, and they play an important role in the life of animals and plants. Many organic substances and their mixtures (plastics, rubber, oil, natural gas and others) are of great importance for the development of the country's national economy.

The chemistry of carbon compounds is called organic chemistry. This is how the great Russian organic chemist A.M. defined the subject of organic chemistry. Butlerov. However, not all carbon compounds are considered organic. Such simple substances as carbon monoxide (II) CO, carbon dioxide CO2, carbonic acid H2CO3 and its salts, for example, CaCO3, K2CO3, are classified as inorganic compounds. Organic substances may contain other elements besides carbon. The most common are hydrogen, halogens, oxygen, nitrogen, sulfur and phosphorus. There are also organic substances containing other elements, including metals.

2. Structure of the carbon atom (C), structure of its electronic shell

2.1 The importance of the carbon atom (C) in the chemical structure of organic compounds

CARBON (lat. Carboneum), C, chemical element of subgroup IVa of the periodic system; atomic number 6, atomic mass 12.0107, belongs to non-metals. Natural carbon consists of two stable nuclides - 12C (98.892% by mass) and 13C (1.108%) and one unstable - C with a half-life of 5730 years.

Prevalence in nature. Carbon accounts for 0.48% of the mass of the earth's crust, in which it ranks 17th among other elements in content. The main carbon-containing rocks are natural carbonates (limestones and dolomites); the amount of carbon in them is about 9,610 tons.

In a free state, carbon is found in nature in the form of fossil fuels, as well as in the form of minerals - diamond and graphite. About 1013 tons of carbon are concentrated in such combustible minerals as coal and brown coal, peat, shale, bitumen, which form powerful accumulations in the bowels of the Earth, as well as in natural combustible gases. Diamonds are extremely rare. Even diamond-bearing rocks (kimberlites) contain no more than 9-10% diamonds weighing, as a rule, no more than 0.4 g. Large diamonds found are usually given a special name. The largest diamond "Cullinan" weighing 621.2 g (3106 carats) was found in South Africa (Transvaal) in 1905, and the largest Russian diamond "Orlov" weighing 37.92 g (190 carats) was found in Siberia in the middle 17th century

Black-gray, opaque, greasy to the touch with a metallic sheen, graphite is an accumulation of flat polymer molecules made of carbon atoms, loosely layered on top of each other. In this case, the atoms inside the layer are more strongly connected to each other than the atoms between the layers.

Diamond is another matter. In its colorless, transparent and highly refracting crystal, each carbon atom is linked by chemical bonds to four similar atoms located at the vertices of the tetrahedron. All ties are the same length and very strong. They form a continuous three-dimensional frame in space. The entire diamond crystal is like one giant polymer molecule that has no “weak” points, because the strength of all bonds is the same.

The density of diamond at 20°C is 3.51 g/cm3, graphite - 2.26 g/cm3. The physical properties of diamond (hardness, electrical conductivity, coefficient of thermal expansion) are almost the same in all directions; it is the hardest of all substances found in nature. In graphite, these properties in different directions - perpendicular or parallel to the layers of carbon atoms - differ greatly: with small lateral forces, parallel layers of graphite shift relative to each other and it stratifies into separate flakes, leaving a mark on the paper. In terms of electrical properties, diamond is a dielectric, while graphite conducts electric current.

When heated without access to air above 1000 °C, diamond turns into graphite. Graphite, when constantly heated under the same conditions, does not change up to 3000 ° C, when it sublimes without melting. The direct transition of graphite into diamond occurs only at temperatures above 3000°C and enormous pressure - about 12 GPa.

The third allotropic modification of carbon, carbyne, was obtained artificially. It is a fine crystalline black powder; in its structure, long chains of carbon atoms are arranged parallel to each other. Each chain has the structure (-C=C) L or (=C=C=) L. The density of carbine is average between graphite and diamond - 2.68-3.30 g/cm 3 . One of the most important features of carbyne is its compatibility with the tissues of the human body, which allows it to be used, for example, in the manufacture of artificial blood vessels that are not rejected by the body (Fig. 1).

Fullerenes got their name not in honor of the chemist, but after the American architect R. Fuller, who proposed building hangars and other structures in the form of domes, the surface of which is formed by pentagons and hexagons (such a dome was built, for example, in the Moscow Sokolniki Park).

Carbon is also characterized by a state with a disordered structure - this is the so-called. amorphous carbon (soot, coke, charcoal) fig. 2. Obtaining carbon (C):

Most of the substances around us are organic compounds. These are animal and plant tissues, our food, medicines, clothing (cotton, wool and synthetic fibers), fuels (oil and natural gas), rubber and plastics, detergents. Currently, more than 10 million such substances are known, and their number increases significantly every year due to the fact that scientists isolate unknown substances from natural objects and create new compounds that do not exist in nature.

Such a variety of organic compounds is associated with the unique feature of carbon atoms to form strong covalent bonds, both among themselves and with other atoms. Carbon atoms, connecting to each other with both simple and multiple bonds, can form chains of almost any length and cycles. The wide variety of organic compounds is also associated with the existence of the phenomenon of isomerism.

Almost all organic compounds also contain hydrogen; they often contain atoms of oxygen, nitrogen, and less often - sulfur, phosphorus, and halogens. Compounds containing atoms of any elements (except O, N, S and halogens) directly bonded to carbon are collectively called organoelement compounds; the main group of such compounds are organometallic compounds (Fig. 3).

The huge number of organic compounds requires their clear classification. The basis of an organic compound is the skeleton of the molecule. The skeleton can have an open (unclosed) structure, in which case the compound is called acyclic (aliphatic; aliphatic compounds are also called fatty compounds, since they were first isolated from fats), and a closed structure, in which case it is called cyclic. The skeleton can be carbon (consist only of carbon atoms) or contain other atoms other than carbon - the so-called. heteroatoms, most often oxygen, nitrogen and sulfur. Cyclic compounds are divided into carbocyclic (carbon), which can be aromatic and alicyclic (containing one or more rings), and heterocyclic.

Hydrogen and halogen atoms are not included in the skeleton, and heteroatoms are included in the skeleton only if they have at least two bonds with carbon. Thus, in ethyl alcohol CH3CH2OH the oxygen atom is not included in the skeleton of the molecule, but in dimethyl ether CH3OCH3 is included in it.

In addition, the acyclic skeleton can be unbranched (all atoms are arranged in one row) or branched. Sometimes an unbranched skeleton is called linear, but it should be remembered that the structural formulas that we most often use convey only the bond order, and not the actual arrangement of atoms. Thus, a “linear” carbon chain has a zigzag shape and can twist in space in various ways.

There are four types of carbon atoms in the molecular skeleton. It is customary to call a carbon atom primary if it forms only one bond with another carbon atom. A secondary atom is bonded to two other carbon atoms, a tertiary atom is bonded to three, and a quaternary atom spends all four of its bonds forming bonds with carbon atoms.

The next classification feature is the presence of multiple bonds. Organic compounds containing only simple bonds are called saturated (limit). Compounds containing double or triple bonds are called unsaturated (unsaturated). In their molecules there are fewer hydrogen atoms per carbon atom than in the limiting ones. Cyclic unsaturated hydrocarbons of the benzene series are classified as a separate class of aromatic compounds.

The third classification feature is the presence of functional groups - groups of atoms that are characteristic of a given class of compounds and determine its chemical properties. Based on the number of functional groups, organic compounds are divided into monofunctional - they contain one functional group, polyfunctional - they contain several functional groups, for example glycerol, and heterofunctional - there are several different groups in one molecule, for example amino acids.

Depending on which carbon atom the functional group is located, the compounds are divided into primary, for example, ethyl chloride CH 3 CH 2 C1, secondary - isopropyl chloride (CH3) 2 CH 1 and tertiary - butyl chloride (CH 8) 8 CCl.

SIBERIAN POLYTECHNIC COLLEGE

STUDENT HANDBOOK

in ORGANIC CHEMISTRY

for specialties of technical and economic profiles

Compiled by: teacher

2012

Structure "STUDENT'S GUIDE TO ORGANIC CHEMISTRY"

EXPLANATORY NOTE

The SS in organic chemistry was compiled to assist students in creating a scientific picture of the world through chemical content, taking into account interdisciplinary and intradisciplinary connections, and the logic of the educational process.

The SS in organic chemistry provides a minimum in volume, but functionally complete content for mastering the state standard chemical education.

The SS in organic chemistry performs two main functions:

I. The information function allows participants in the educational process to gain an understanding of the content, structure of the subject, and the relationship of concepts through diagrams, tables and algorithms.

II. The organizational-planning function involves highlighting the stages of training, structuring educational material, and creates ideas about the content of the intermediate and final certification.

SS involves the formation of a system of knowledge, skills and methods of activity, and develops the ability of students to work with reference materials.

CHRONOLOGICAL TABLE “DEVELOPMENT OF ORGANIC CHEMISTRY”

BASIC POINTS

THEORIES OF THE STRUCTURE OF ORGANIC COMPOUNDS

A. M. BUTLEROVA

1. A. in M. are connected in a certain sequence, according to their valence.

2. The properties of substances depend not only on the qualitative and quantitative composition, but also on the chemical structure. Isomers. Isomerism.

3. A. and A. groups mutually influence each other.

4. By the properties of a substance, you can determine the structure, and by the structure, you can determine the properties.

Isomers and homologues.

TSOS value

1. Explained the structure of M. known substances and their properties.

2. Made it possible to foresee the existence of unknown substances and find ways to synthesize them.

3. Explain the diversity of organic substances.

Classification of hydrocarbons.

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Homologous series

ALKANES (SARITIZED HYDROCARBONS)

Homologous series

RADICALS FORMED FROM ALKANES

General information about hydrocarbons.

DIV_ADBLOCK31">

Chemical properties of alkanes

(saturated hydrocarbons).

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Chemical properties of alkynes

(acetylene hydrocarbons).

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Genetic relationship between hydrocarbons.

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MOLECULAR MASSES OF SOME ORGANIC SUBSTANCES.

Algorithm for solving problems

1. Study the conditions of the problem carefully: determine with what quantities the calculations will be carried out, designate them with letters, establish their units of measurement, numerical values, determine which quantity is the desired one.

2. Write down these tasks in the form of brief conditions.

3. If the problem conditions involve the interaction of substances, write down the equation of the reaction(s) and balance it (their) coefficients.

4. Find out the quantitative relationships between the problem data and the desired value. To do this, divide your actions into stages, starting with the question of the problem, finding out the pattern with which you can determine the desired value at the last stage of the calculations. If the source data is missing any quantities, think about how they can be calculated, i.e., determine the preliminary stages of calculation. There may be several of these stages.

5. Determine the sequence of all stages of solving the problem, write down the necessary calculation formulas.

6. Substitute the corresponding numerical values ​​of the quantities, check their dimensions, and make calculations.

Deriving formulas of compounds.

This type of calculation is extremely important for chemical practice, because it allows, based on experimental data, to determine the formula of a substance (simple and molecular).

Based on data from qualitative and quantitative analyses, the chemist first finds the ratio of atoms in a molecule (or other structural unit of a substance), i.e., its simplest formula.
For example, analysis showed that the substance is a hydrocarbon
CxHy, in which the mass fractions of carbon and hydrogen are respectively 0.8 and 0.2 (80% and 20%). To determine the ratio of atoms of elements, it is enough to determine their amount of substance (number of moles): Integers (1 and 3) are obtained by dividing the number 0.2 by the number 0.0666. We take the number 0.0666 as 1. The number 0.2 is 3 times greater than the number 0.0666. So CH3 is the simplest the formula of this substance. The ratio of C and H atoms, equal to 1:3, corresponds to countless formulas: C2H6, C3H9, C4H12, etc., but from this series only one formula is molecular for a given substance, i.e., reflecting the true number of atoms in its molecule. To calculate the molecular formula, in addition to the quantitative composition of a substance, it is necessary to know its molecular mass.

To determine this value, the value of the relative gas density D is often used. So, for the above case, DH2 = 15. Then M(CxHy) = 15µM(H2) = 152 g/mol = 30 g/mol.
Since M(CH3) = 15, the subscripts in the formula must be doubled to match the true molecular weight. Hence, molecular substance formula: C2H6.

Determining the formula of a substance depends on the accuracy of mathematical calculations.

When finding the value n element should take into account at least two decimal places and carefully round numbers.

For example, 0.8878 ≈ 0.89, but not 1. The ratio of atoms in a molecule is not always determined by simply dividing the resulting numbers by a smaller number.

by mass fractions of elements.

Task 1. Establish the formula of a substance that consists of carbon (w=25%) and aluminum (w=75%).

Let's divide 2.08 by 2. The resulting number 1.04 does not fit an integer number of times into the number 2.78 (2.78:1.04=2.67:1).

Now let's divide 2.08 by 3.

This produces the number 0.69, which fits exactly 4 times into the number 2.78 and 3 times into the number 2.08.

Therefore, the indices x and y in the formula of the substance AlxCy are 4 and 3, respectively.

Answer: Al4C3(aluminum carbide).

Algorithm for finding the chemical formula of a substance

by its density and mass fractions of elements.

A more complex version of problems for deriving formulas of compounds is the case when the composition of a substance is specified through the combustion products of these compounds.

Problem 2. When a hydrocarbon weighing 8.316 g was burned, 26.4 g of CO2 was formed. The density of the substance under normal conditions is 1.875 g/ml. Find its molecular formula.

General information about hydrocarbons.

(continuation)

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Natural sources of hydrocarbons.

Oil – fossil, liquid fuel, a complex mixture of organic substances: saturated hydrocarbons, paraffins, naphthenes, aromatics, etc. The composition of oil usually includes oxygen-, sulfur- and nitrogen-containing substances.

An oily liquid with a characteristic odor, dark in color, lighter than water. The most important source of fuel, lubricating oils and other petroleum products. The main (primary) processing process is distillation, which results in the production of gasoline, naphtha, kerosene, diesel oils, fuel oil, petroleum jelly, paraffin, and tar. Secondary recycling processes ( cracking, pyrolysis) make it possible to obtain additional liquid fuel, aromatic hydrocarbons (benzene, toluene, etc.), etc.

Petroleum gases – a mixture of various gaseous hydrocarbons dissolved in oil; they are released during extraction and processing. They are used as fuel and chemical raw materials.

Petrol– colorless or yellowish liquid, consists of a mixture of hydrocarbons ( C5 – C11 ). It is used as motor fuel, solvent, etc.

Naphtha– a transparent yellowish liquid, a mixture of liquid hydrocarbons. It is used as diesel fuel, solvent, hydraulic fluid, etc.

Kerosene– transparent, colorless or yellowish liquid with a blue tint. Used as fuel for jet engines, for domestic needs, etc.

Solar- yellowish liquid. Used for the production of lubricating oils.

Fuel oil– heavy oil fuel, mixture of paraffins. Used in the production of oils, heating oil, bitumen, and for processing into light motor fuel.

Benzene– colorless mobile liquid with a characteristic odor. Used for the synthesis of organic compounds, as a raw material for the production of plastics, as a solvent, for the production of explosives, in the aniline paint industry

Toluene- analogue of benzene. Used in the production of caprolactam, explosives, benzoic acid, saccharin, as a solvent, in the aniline dye industry, etc.

Lubricating oils– Used in various fields of technology to reduce friction. parts to protect metals from corrosion, as a cutting fluid.

Tar- black resinous mass. Used for lubrication, etc.

Petrolatum– a mixture of mineral oil and paraffins. Used in electrical engineering, to lubricate bearings, to protect metals from corrosion, etc.

Paraffin– a mixture of solid saturated hydrocarbons. Used as an electrical insulator in chemical applications. industry - for the production of higher acids and alcohols, etc.

Plastic– materials based on high molecular weight compounds. Used for the production of various technical products and household items.

Asphalt Ore– a mixture of oxidized hydrocarbons. It is used for the manufacture of varnishes, in electrical engineering, and for paving streets.

Mountain wax– a mineral from the group of petroleum bitumens. Used as an electrical insulator, for the preparation of various lubricants and ointments, etc.

Artificial wax– purified mountain wax.

Coal – a solid fuel fossil of plant origin, black or black-gray. Contains 75–97% carbon. Used as fuel and as a raw material for the chemical industry.

Coke- a sintered solid product formed when certain coals are heated in coke ovens to 900–1050° C. Used in blast furnaces.

Coke gas– gaseous products of coking of fossil coals. Comprises CH4, H2, CO etc., also contains non-flammable impurities. Used as a high-calorie fuel.

Ammonia water– liquid product of dry distillation of coal. It is used to produce ammonium salts (nitrogen fertilizers), ammonia, etc.

Coal tar– a thick dark liquid with a characteristic odor, a product of dry distillation of coal. Used as raw material for chemicals. industry.

Benzene– a colorless mobile liquid with a characteristic odor, one of the products of coal tar. They are used for the synthesis of organic compounds, as explosives, as raw materials for the production of plastics, as a dye, as a solvent, etc.

Naphthalene– a solid crystalline substance with a characteristic odor, one of the products of coal tar. Naphthalene derivatives are used to produce dyes and explosives, etc.

Medicines- the coke industry produces a number of drugs (carbolic acid, phenacytin, salicylic acid, saccharin, etc.).

Pitch– a solid (viscous) black mass, a residue from the distillation of coal tar. Used as a waterproofing agent, for the production of fuel briquettes, etc.

Toluene– an analogue of benzene, one of the products of coal tar. Used for the production of explosives, caprolactam, benzoic acid, saccharin, as a dye, etc.

Dyes– one of the products of coke production, obtained by processing benzene, naphthalene and phenol. Used in the national economy.

Aniline– colorless oily liquid, poisonous. It is used for the production of various organic substances, aniline dyes, various azo dyes, the synthesis of drugs, etc.

Saccharin– a solid white crystalline substance with a sweet taste, obtained from toluene. Used instead of sugar for diabetes, etc.

BB– derivatives of coal obtained through the process of dry distillation. They are used in the military industry, mining and other sectors of the national economy.

Phenol– a white or pink crystalline substance with a characteristic strong odor. It is used in the production of phenol-formaldehyde plastics, synthetic nylon fiber, dyes, medicines, etc.

Plastic– materials based on high-molecular compounds. Used for the production of various technical products and household items.

It is difficult to imagine progress in any area of ​​the economy without chemistry - in particular, without organic chemistry. All areas of the economy are connected with modern chemical science and technology.

Organic chemistry studies substances containing carbon, with the exception of carbon monoxide, carbon dioxide and carbonic acid salts (these compounds are closer in properties to inorganic compounds).

As a science, organic chemistry did not exist until the middle of the 18th century. By that time, three types of chemistry were distinguished: animal, plant and mineral chemistry. Animal chemistry studied the substances that make up animal organisms; vegetable - substances that make up plants; mineral - substances that are part of inanimate nature. This principle, however, did not allow the separation of organic substances from inorganic ones. For example, succinic acid belonged to the group of mineral substances, since it was obtained by distillation of fossil amber, potash was included in the group of plant substances, and calcium phosphate was included in the group of animal substances, since they were obtained by calcination of plant (wood) and animal (bone) materials, respectively. .

In the first half of the 19th century, it was proposed to separate carbon compounds into an independent chemical discipline - organic chemistry.

Among scientists at that time, the vitalistic worldview dominated, according to which organic compounds are formed only in a living organism under the influence of a special, supernatural “vital force.” This meant that it was impossible to obtain organic substances by synthesis from inorganic ones, and that there was an insurmountable gap between organic and inorganic compounds. Vitalism became so entrenched in the minds of scientists that for a long time no attempts were made to synthesize organic substances. However, vitalism was refuted by practice, by chemical experiment.

In 1828, the German chemist Wöhler, working with ammonium cyanate, accidentally obtained urea

O
II
NH2-C-NH2.

In 1854, the Frenchman Berthelot synthesized substances related to fats, and in 1861, the Russian scientist Butlerov synthesized substances related to the class of sugars. These were heavy blows to the vitalistic theory, finally shattering the belief that the synthesis of organic compounds is impossible.

These and other achievements of chemists required a theoretical explanation and generalization of possible routes for the synthesis of organic compounds and the connection of their properties with structure.

Historically, the first theory of organic chemistry was the theory of radicals (J. Dumas, J. Liebig, I. Berzelius). According to the authors, many transformations of organic compounds proceed in such a way that some groups of atoms (radicals), without changing, pass from one organic compound to another. However, it was soon discovered that in organic radicals, hydrogen atoms can be replaced even by atoms that are chemically different from hydrogen, such as chlorine atoms, and the type of chemical compound is preserved.

The theory of radicals was replaced by a more advanced theory of types that covered more experimental material (O. Laurent, C. Gerard, J. Dumas). The theory of types classified organic substances according to types of transformations. The type of hydrogen included hydrocarbons, the type of hydrogen chloride - halogen derivatives, the type of water - alcohols, esters, acids and their anhydrides, the type of ammonia - amines. However, the enormous experimental material that was accumulating no longer fit into the known types and, in addition, the theory of types could not predict the existence and ways of synthesizing new organic compounds. The development of science required the creation of a new, more progressive theory, for the birth of which some prerequisites already existed: the tetravalency of carbon was established (A. Kekule and A. Kolbe, 1857), the ability of the carbon atom to form chains of atoms was shown (A. Kekule and A. Cooper, 1857).

The decisive role in creating the theory of the structure of organic compounds belongs to the great Russian scientist Alexander Mikhailovich Butlerov. On September 19, 1861, at the 36th Congress of German Naturalists, A.M. Butlerov published it in his report “On the Chemical Structure of Matter.”

The main provisions of the theory of chemical structure of A.M. Butlerov can be reduced to the following.

1. All atoms in a molecule of an organic compound are bonded to each other in a certain sequence in accordance with their valence. Changing the sequence of atoms leads to the formation of a new substance with new properties. For example, the composition of the substance C2H6O corresponds to two different compounds: dimethyl ether (CH3-O-CH3) and ethyl alcohol (C2H5OH).

2. The properties of substances depend on their chemical structure. Chemical structure is a certain order in the alternation of atoms in a molecule, in the interaction and mutual influence of atoms on each other - both neighboring and through other atoms. As a result, each substance has its own special physical and chemical properties. For example, dimethyl ether is an odorless gas, insoluble in water, mp. = -138°C, t°boil. = 23.6°C; ethyl alcohol - liquid with odor, soluble in water, mp. = -114.5°C, t°boil. = 78.3°C.
This position of the theory of the structure of organic substances explained the phenomenon of isomerism, which is widespread in organic chemistry. The given pair of compounds - dimethyl ether and ethyl alcohol - is one of the examples illustrating the phenomenon of isomerism.

3. The study of the properties of substances allows us to determine their chemical structure, and the chemical structure of substances determines their physical and chemical properties.

4. Carbon atoms are able to connect with each other, forming carbon chains of various types. They can be both open and closed (cyclic), both direct and branched. Depending on the number of bonds the carbon atoms spend connecting to each other, the chains can be saturated (with single bonds) or unsaturated (with double and triple bonds).

5. Each organic compound has one specific structural formula or structural formula, which is built based on the provision of tetravalent carbon and the ability of its atoms to form chains and cycles. The structure of a molecule as a real object can be studied experimentally using chemical and physical methods.

A.M. Butlerov did not limit himself to theoretical explanations of his theory of the structure of organic compounds. He conducted a series of experiments, confirming the predictions of the theory by obtaining isobutane, tert. butyl alcohol, etc. This made it possible for A.M. Butlerov to declare in 1864 that the available facts allow us to vouch for the possibility of synthetically producing any organic substance.

In the further development and substantiation of the theory of the structure of organic compounds, Butlerov’s followers played a major role - V.V. Markovnikov, E.E. Wagner, N.D. Zelinsky, A.N. Nesmeyanov and others.

The modern period of development of organic chemistry in the field of theory is characterized by the increasing penetration of quantum mechanics methods into organic chemistry. With their help, questions about the causes of certain manifestations of the mutual influence of atoms in molecules are resolved. In the field of development of organic synthesis, the modern period is characterized by significant advances in the production of numerous organic compounds, which include natural substances - antibiotics, various medicinal compounds, and numerous high-molecular compounds. Organic chemistry has deeply penetrated the field of physiology. Thus, from a chemical point of view, the hormonal function of the body and the mechanism of transmission of nerve impulses have been studied. Scientists have come close to resolving the issue of protein structure and synthesis.

Organic chemistry as an independent science continues to exist and develop intensively. This is due to the following reasons:

1. The variety of organic compounds, due to the fact that carbon, unlike other elements, is able to combine with each other, giving long chains (isomers). Currently, about 6 million organic compounds are known, while inorganic compounds are only about 700 thousand.

2. The complexity of molecules of organic substances containing up to 10 thousand atoms (for example, natural biopolymers - proteins, carbohydrates).

3. The specificity of the properties of organic compounds compared to inorganic ones (instability at relatively low temperatures, low - up to 300 ° C - melting point, flammability).

4. Slow reactions between organic substances compared to reactions characteristic of inorganic substances, the formation of by-products, the specifics of the isolation of the resulting substances and technological equipment.

5. The enormous practical importance of organic compounds. They are our food and clothing, fuel, various medicines, numerous polymeric materials, etc.

Classification of organic compounds

A huge number of organic compounds are classified taking into account the structure of the carbon chain (carbon skeleton) and the presence of functional groups in the molecule.

The diagram shows the classification of organic compounds depending on the structure of the carbon chain.

Organic compounds

Acyclic (aliphatic)
(open circuit connections)

Cyclic
(closed circuit connections)

Saturated (ultimate)

Unsaturated (unsaturated)

Carbocyclic (the cycle consists only of carbon atoms)

Heterocyclic (the cycle consists of carbon atoms and other elements)

Alicyclic (aliphatic cyclic)

Aromatic

The simplest representatives of acyclic compounds are aliphatic hydrocarbons - compounds containing only carbon and hydrogen atoms. Aliphatic hydrocarbons can be saturated (alkanes) and unsaturated (alkenes, alkadienes, alkynes).

The simplest representative of alicyclic hydrocarbons is cyclopropane, containing a ring of three carbon atoms.

The aromatic series includes aromatic hydrocarbons - benzene, naphthalene, anthracene, etc., as well as their derivatives.

Heterocyclic compounds may contain in the cycle, in addition to carbon atoms, one or more atoms of other elements - heteroatoms (oxygen, nitrogen, sulfur, etc.).

In each series presented, organic compounds are divided into classes depending on their composition and structure. The simplest class of organic compounds are hydrocarbons. When hydrogen atoms in hydrocarbons are replaced by other atoms or groups of atoms (functional groups), other classes of organic compounds of this series are formed.

A functional group is an atom or group of atoms that determines whether a compound belongs to classes of organic compounds and determines the main directions of its chemical transformations.

Compounds with one functional group are called monofunctional (methanol CH3-OH), with several identical functional groups - polyfunctional (glycerol

CH2-
I
OH CH-
I
OH CH2),
I
OH

with several different functional groups - heterofunctional (lactic acid

CH3-
CH-COOH).
I
OH

Compounds of each class form homologous series. A homologous series is an infinite series of organic compounds that have a similar structure and, therefore, similar chemical properties and differ from each other by any number of CH2 groups (homologous difference).

The main classes of organic compounds are as follows:

I. Hydrocarbons (R-H).

II. Halogen derivatives (R-Hlg).

III. Alcohols (R-OH).

O
IV. Esters and esters (R-O-R’, R-C).
\
OR'

O
V. Carbonyl compounds (aldehydes and ketones) (R-C
\
H

O
II
, R-C-R).

O
VI. Carboxylic acids R-C).
\
OH

R
I
VII. Amines (R-NH2, NH, R-N-R’).
I I
R' R''

VIII. Nitro compounds (R-NO2).

IX. Sulfonic acids (R-SO3H).

The number of known classes of organic compounds is not limited to those listed; it is large and is constantly increasing with the development of science.

All classes of organic compounds are interrelated. The transition from one class of compounds to another is carried out mainly due to transformations of functional groups without changing the carbon skeleton.

Classification of reactions of organic compounds according to the nature of chemical transformations

Organic compounds are capable of a variety of chemical transformations, which can take place both without changing the carbon skeleton and with it. Most reactions take place without changing the carbon skeleton.

I. Reactions without changing the carbon skeleton

Reactions without changing the carbon skeleton include the following:

1) substitution: RH + Br2 ® RBr + HBr,

2) addition: CH2=CH2 + Br2 ® CH2Br - CH2Br,

3) elimination (elimination): CH3-CH2-Cl ® CH2=CH2 + HCl,

4) isomerization: CH3-CH2-CєСH

------®
¬------

Substitution reactions are characteristic of all classes of organic compounds. Hydrogen atoms or atoms of any other element except carbon can be replaced.

Addition reactions are typical for compounds with multiple bonds, which can be between carbon atoms, carbon and oxygen, carbon and nitrogen, etc., as well as for compounds containing atoms with free electron pairs or vacant orbitals.

Compounds containing electronegative groups are capable of elimination reactions. Substances such as water, hydrogen halides, and ammonia are easily split off.

Unsaturated compounds and their derivatives are especially prone to isomerization reactions without changing the carbon skeleton.

II. Reactions involving changes in the carbon skeleton

This type of transformation of organic compounds includes the following reactions:

1) lengthening the chain,

2) shortening the chain,

3) chain isomerization,

4) cyclization,

5) opening the cycle,

6) compression and expansion of the cycle.

Chemical reactions occur with the formation of various intermediate products. The path along which the transition from starting substances to final products occurs is called the reaction mechanism. Depending on the reaction mechanism, they are divided into radical and ionic. Covalent bonds between atoms A and B can be broken in such a way that an electron pair is either shared between atoms A and B or transferred to one of the atoms. In the first case, particles A and B, having received one electron each, become free radicals. Homolytic cleavage occurs:

A: B ® A. + .B

In the second case, the electron pair goes to one of the particles and two opposite ions are formed. Because the resulting ions have different electronic structures, this type of bond breaking is called heterolytic cleavage:

A: B ® A+ + :B-

A positive ion in reactions will tend to attach an electron to itself, i.e. it will behave like an electrophilic particle. A negative ion - a so-called nucleophilic particle - will attack centers with excess positive charges.

The study of conditions and methods, as well as the mechanisms of reactions of organic compounds, constitutes the main content of this course in organic chemistry.

Issues of nomenclature of organic compounds, as a rule, are presented in all textbooks of organic chemistry, so we deliberately omit consideration of this material, drawing attention to the fact that in all cases of writing reaction equations, the starting and resulting compounds are provided with appropriate names. These names, with knowledge of the basics of nomenclature, will allow everyone to independently resolve issues related to the nomenclature of organic compounds.

The study of organic chemistry usually begins with the aliphatic series and the simplest class of substances - hydrocarbons.

If you have entered the university, but by this time have not understood this difficult science, we are ready to reveal a few secrets to you and help you study organic chemistry from scratch (for dummies). All you have to do is read and listen.

Basics of organic chemistry

Organic chemistry is distinguished as a separate subtype due to the fact that the object of its study is everything that contains carbon.

Organic chemistry is a branch of chemistry that deals with the study of carbon compounds, the structure of such compounds, their properties and methods of joining.

As it turned out, carbon most often forms compounds with the following elements - H, N, O, S, P. By the way, these elements are called organogens.

Organic compounds, the number of which today reaches 20 million, are very important for the full existence of all living organisms. However, no one doubted it, otherwise the person would have simply thrown the study of this unknown into the back burner.

The goals, methods and theoretical concepts of organic chemistry are presented as follows:

• Separation of fossil, animal or plant materials into individual substances;
• Purification and synthesis of various compounds;
• Identification of the structure of substances;
• Determination of the mechanics of chemical reactions;
• Finding the relationship between the structure and properties of organic substances.

A little history of organic chemistry

You may not believe it, but back in ancient times, the inhabitants of Rome and Egypt understood something about chemistry.

As we know, they used natural dyes. And often they had to use not a ready-made natural dye, but extract it by isolating it from a whole plant (for example, alizarin and indigo contained in plants).

We can also remember the culture of drinking alcohol. The secrets of producing alcoholic beverages are known in every nation. Moreover, many ancient peoples knew recipes for preparing “hot water” from starch- and sugar-containing products.

This went on for many, many years, and only in the 16th and 17th centuries did some changes and small discoveries begin.

In the 18th century, a certain Scheele learned to isolate malic, tartaric, oxalic, lactic, gallic and citric acid.

Then it became clear to everyone that the products that had been isolated from plant or animal raw materials had many common features. At the same time, they were very different from inorganic compounds. Therefore, the servants of science urgently needed to separate them into a separate class, and this is how the term “organic chemistry” appeared.

Despite the fact that organic chemistry itself as a science appeared only in 1828 (it was then that Mr. Wöhler managed to isolate urea by evaporating ammonium cyanate), in 1807 Berzelius introduced the first term into the nomenclature in organic chemistry for dummies:

The branch of chemistry that studies substances obtained from organisms.

The next important step in the development of organic chemistry is the theory of valence, proposed in 1857 by Kekule and Cooper, and the theory of chemical structure of Mr. Butlerov from 1861. Even then, scientists began to discover that carbon was tetravalent and capable of forming chains.

In general, since then, science has regularly experienced shocks and excitement thanks to new theories, discoveries of chains and compounds, which allowed the active development of organic chemistry.

Science itself emerged due to the fact that scientific and technological progress was unable to stand still. He went on and on, demanding new solutions. And when there was no longer enough coal tar in industry, people simply had to create a new organic synthesis, which over time grew into the discovery of an incredibly important substance, which to this day is more expensive than gold - oil. By the way, it was thanks to organic chemistry that its “daughter” was born - a subscience that was called “petrochemistry”.

But this is a completely different story that you can study for yourself. Next, we invite you to watch a popular science video about organic chemistry for dummies:

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