For cooking, dyes, clothes, medicines, people have long learned to use various substances. Over time, a sufficient amount of information about the properties of certain substances has accumulated, which has made it possible to improve the methods of their production, processing, etc. And it turned out that many mineral (inorganic substances) can be obtained directly.
But some of the substances used by man were not synthesized by him, because they were obtained from living organisms or plants. These substances are called organic. Organic substances could not be synthesized in the laboratory. At the beginning of the 19th century, such a doctrine as vitalism (vita - life) actively developed, according to which organic substances arise only due to "life force" and it is impossible to create them "artificially".
But as time went on and science developed, new facts about organic substances appeared that ran counter to the existing theory of the vitalists.
In 1824, the German scientist F. Wöhler synthesized oxalic acid for the first time in the history of chemical science – organic matter from inorganic substances (cyanide and water):
(CN) 2 + 4H 2 O → COOH - COOH + 2NH 3
In 1828, Wöller heated sodium cyanate with sulfuric ammonium and synthesized urea - product of vital activity of animal organisms:
NaOCN + (NH 4) 2 SO 4 → NH 4 OCN → NH 2 OCNH 2
These discoveries played an important role in the development of science in general, and chemistry in particular. Scientists-chemists began to gradually move away from the vitalistic doctrine, and the principle of dividing substances into organic and inorganic proved to be untenable.
Currently substances still divided into organic and inorganic but the criterion for separation is already slightly different.
Substances are called organic containing carbon in their composition, they are also called carbon compounds. There are about 3 million such compounds, while the remaining compounds are about 300 thousand.
Substances that do not contain carbon are called inorganic and. But there are exceptions to the general classification: there are a number of compounds that contain carbon, but they belong to inorganic substances (carbon monoxide and dioxide, carbon disulfide, carbonic acid and its salts). All of them are similar in composition and properties to inorganic compounds.
In the course of the study of organic substances, new difficulties arose: on the basis of theories about inorganic substances, it is impossible to reveal the patterns of the structure of organic compounds, to explain the valency of carbon. Carbon in different compounds had different valencies.
In 1861, the Russian scientist A.M. Butlerov was the first to obtain a sugary substance by synthesis.
When studying hydrocarbons, A.M. Butlerov realized that they represent a very special class of chemicals. Analyzing their structure and properties, the scientist identified several patterns. They formed the basis of the theories of chemical structure.
1. The molecule of any organic substance is not disordered, the atoms in the molecules are connected to each other in a certain sequence according to their valencies. Carbon in organic compounds is always tetravalent.
2. The sequence of interatomic bonds in a molecule is called its chemical structure and is reflected by one structural formula (structure formula).
3. The chemical structure can be established by chemical methods. (Currently modern physical methods are also used).
4. The properties of substances depend not only on the composition of the molecules of the substance, but on their chemical structure (the sequence of connection of the atoms of the elements).
5. By the properties of a given substance, you can determine the structure of its molecule, and by the structure of the molecule – anticipate properties.
6. Atoms and groups of atoms in a molecule interact with each other.
This theory became the scientific foundation of organic chemistry and accelerated its development. Based on the provisions of the theory, A.M. Butlerov described and explained the phenomenon isomerism, predicted the existence of various isomers and obtained some of them for the first time.
Consider the chemical structure of ethane – C2H6. Denoting the valency of the elements with dashes, we will depict the ethane molecule in the order of the connection of atoms, that is, we will write a structural formula. According to the theory of A.M. Butlerov, it will look like this:
Hydrogen and carbon atoms are bound into one particle, hydrogen valence is equal to one, and carbon – four. Two carbon atoms are linked by a carbon bond – carbon (C – FROM). The ability of carbon to form C – The C-bond is understood from the chemical properties of carbon. On the outer electron layer, the carbon atom has four electrons, the ability to donate electrons is the same as to add the missing ones. Therefore, carbon most often forms compounds with a covalent bond, that is, due to the formation of electron pairs with other atoms, including carbon atoms with each other.
This is one of the reasons for the diversity of organic compounds.
Compounds that have the same composition but different structures are called isomers. The phenomenon of isomerism – one of the reasons for the diversity of organic compounds
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The largest event in the development of organic chemistry was the creation in 1961 by the great Russian scientist A.M. Butlerov's theory of the chemical structure of organic compounds.
Before A.M. Butlerov, it was considered impossible to know the structure of the molecule, that is, the order of the chemical bond between atoms. Many scientists even denied the reality of atoms and molecules.
A.M. Butlerov refuted this opinion. He proceeded from correct materialistic and philosophical ideas about the reality of the existence of atoms and molecules, about the possibility of knowing the chemical bond of atoms in a molecule. He showed that the structure of a molecule can be established empirically by studying the chemical transformations of a substance. Conversely, knowing the structure of the molecule, one can derive the chemical properties of the compound.
The theory of chemical structure explains the diversity of organic compounds. It is due to the ability of tetravalent carbon to form carbon chains and rings, combine with atoms of other elements and the presence of isomerism in the chemical structure of organic compounds. This theory laid the scientific foundations of organic chemistry and explained its most important regularities. The basic principles of his theory A.M. Butlerov stated in the report "On the theory of chemical structure".
The main provisions of the theory of structure are as follows:
1) in molecules, atoms are connected to each other in a certain sequence in accordance with their valency. The bonding order of atoms is called chemical structure;
2) the properties of a substance depend not only on which atoms and in what quantity are part of its molecule, but also on the order in which they are interconnected, that is, on the chemical structure of the molecule;
3) atoms or groups of atoms that formed a molecule mutually influence each other.
In the theory of chemical structure, much attention is paid to the mutual influence of atoms and groups of atoms in a molecule.
Chemical formulas, which depict the order of connection of atoms in molecules, are called structural formulas or structure formulas.
The value of the theory of chemical structure of A.M. Butlerov:
1) is an essential part of the theoretical foundation of organic chemistry;
2) in importance it can be compared with the Periodic system of elements of D.I. Mendeleev;
3) it made it possible to systematize a huge amount of practical material;
4) made it possible to predict in advance the existence of new substances, as well as indicate ways to obtain them.
The theory of chemical structure serves as the guiding basis in all research in organic chemistry.
5. Isomerism. The electronic structure of atoms of elements of small periods. Chemical bond
The properties of organic substances depend not only on their composition, but also on the order of connection of atoms in a molecule.
Isomers are substances that have the same composition and the same molar mass, but different molecular structure, and therefore have different properties.
Scientific significance of the theory of chemical structure:
1) deepens ideas about the substance;
2) indicates the way to the knowledge of the internal structure of molecules;
3) makes it possible to understand the facts accumulated in chemistry; predict the existence of new substances and find ways to synthesize them.
All this theory greatly contributed to the further development of organic chemistry and the chemical industry.
The German scientist A. Kekule expressed the idea of connecting carbon atoms to each other in a chain.
The doctrine of the electronic structure of atoms.
Features of the doctrine of the electronic structure of atoms: 1) made it possible to understand the nature of the chemical bond of atoms; 2) find out the essence of the mutual influence of atoms.
The state of electrons in atoms and the structure of electron shells.
Electron clouds are areas of the greatest probability of an electron being present, which differ in their shape, size, and orientation in space.
In the atom hydrogen a single electron during its movement forms a negatively charged cloud of a spherical (spherical) shape.
S-electrons are electrons that form a spherical cloud.
The hydrogen atom has one s-electron.
In the atom helium are two s-electrons.
Features of the helium atom: 1) clouds of the same spherical shape; 2) the highest density is equally removed from the core; 3) electron clouds are combined; 4) form a common two-electron cloud.
Features of the lithium atom: 1) has two electronic layers; 2) has a cloud of spherical shape, but is much larger than the inner two-electron cloud; 3) the electron of the second layer is weaker attracted to the nucleus than the first two; 4) is easily captured by other atoms in redox reactions; 5) has an s-electron.
Features of the beryllium atom: 1) the fourth electron is an s-electron; 2) the spherical cloud coincides with the cloud of the third electron; 3) there are two paired s-electrons in the inner layer and two paired s-electrons in the outer.
The more electron clouds overlap when atoms connect, the more energy is released and the stronger chemical bond.
Chemistry is a science that gives us all the variety of materials and household items that we, without hesitation, use every day. But in order to come to the discovery of such a variety of compounds that is known today, many chemists had to go through a difficult scientific path.
Huge work, numerous successful and unsuccessful experiments, a colossal theoretical knowledge base - all this led to the formation of various areas of industrial chemistry, made it possible to synthesize and use modern materials: rubbers, plastics, plastics, resins, alloys, various glasses, silicones, and so on.
One of the most famous, honored chemists who made an invaluable contribution to the development of organic chemistry was the Russian man A. M. Butlerov. We will briefly consider his works, merits and results of work in this article.
short biography
The date of birth of the scientist is September 1828, the number varies in different sources. He was the son of Lieutenant Colonel Mikhail Butlerov, he lost his mother quite early. He lived all his childhood in his grandfather's family estate, in the village of Podlesnaya Shentala (now a district of the Republic of Tatarstan).
He studied in different places: first in a closed private school, then in a gymnasium. Later he entered Kazan University in the Department of Physics and Mathematics. However, despite this, he was most interested in chemistry. The future author of the theory of the structure of organic compounds remained on the spot after graduation as a teacher.
1851 - the time of defending the first dissertation work of a scientist on the topic "Oxidation of organic compounds". After a brilliant performance, he was given the opportunity to manage all chemistry at his university.
The scientist died in 1886 where he spent his childhood, in the family estate of his grandfather. He was buried in the local family chapel.
The scientist's contribution to the development of chemical knowledge
Butlerov's theory of the structure of organic compounds is, of course, his main work. However, not the only one. It was this scientist who first created the Russian school of chemists.
Moreover, scientists who later had great weight in the development of all science came out of its walls. These are the following people:
- Markovnikov;
- Zaitsev;
- Kondakov;
- Favorsky;
- Konovalov;
- Lvov and others.
Works in organic chemistry
There are many such works. After all, Butlerov spent almost all his free time in the laboratory of his university, carrying out various experiments, drawing conclusions and conclusions. This is how the theory of organic compounds was born.
There are several particularly capacious works of the scientist:
- he created a report for a conference on the topic "On the chemical structure of matter";
- dissertation work "About essential oils";
- first scientific work "Oxidation of organic compounds".
Before its formulation and creation, the author of the theory of the structure of organic compounds studied the works of other scientists from different countries for a long time, studied their works, including experimental ones. Only later, having generalized and systematized the knowledge gained, did he reflect all the conclusions in the provisions of his nominal theory.
Theory of the structure of organic compounds A. M. Butlerova
The 19th century is marked by the rapid development of almost all sciences, including chemistry. In particular, vast discoveries on carbon and its compounds continue to be accumulated, striking everyone with their diversity. However, no one dares to systematize and streamline all this factual material, bring to a common denominator and reveal common patterns on which everything is built.
Butlerov A.M. was the first to do this. It was he who owns the ingenious theory of the chemical structure of organic compounds, the provisions of which he spoke en masse at the German conference of chemists. This was the beginning of a new era in the development of science, organic chemistry rose to
The scientist himself went to this gradually. He conducted many experiments and predicted the existence of substances with given properties, discovered some types of reactions and saw the future behind them. He studied the works of his colleagues and their discoveries a lot. Only against this background, through careful and painstaking work, did he manage to create his masterpiece. And now the theory of the structure of organic compounds in this is practically the same as the periodic system in the inorganic.
Discoveries of a scientist before creating a theory
What discoveries were made and theoretical justifications given to scientists before the theory of the structure of organic compounds by A. M. Butlerov appeared?
- The domestic genius was the first to synthesize such organic substances as urotropine, formaldehyde, methylene iodide and others.
- He synthesized a sugar-like substance (tertiary alcohol) from inorganics, thereby dealing another blow to the theory of vitalism.
- He predicted the future for polymerization reactions, calling them the best and most promising.
- Isomerism was explained for the first time only by him.
Of course, these are only the main milestones of his work. In fact, many years of painstaking work of a scientist can be described for a long time. However, the theory of the structure of organic compounds has become the most significant today, the provisions of which will be discussed further.
The first position of the theory
In 1861, the great Russian scientist, at a congress of chemists in the city of Speyer, shared with colleagues his views on the causes of the structure and diversity of organic compounds, expressing all this in the form of theoretical provisions.
The very first point is as follows: all atoms within a single molecule are connected in a strict sequence, which is determined by their valency. In this case, the carbon atom exhibits a valency index of four. Oxygen has a value of this indicator equal to two, hydrogen - to one.
He proposed to call such a feature chemical. Later, the designations of expressing it on paper using graphic full structural, abbreviated and molecular formulas were adopted.
This also includes the phenomenon of the connection of carbon particles with each other in endless chains of various structures (linear, cyclic, branched).
In general, Butlerov's theory of the structure of organic compounds, with its first position, determined the significance of valence and a single formula for each compound, reflecting the properties and behavior of a substance during reactions.
The second position of the theory
In this paragraph, an explanation was given to the diversity of organic compounds in the world. Based on the carbon compounds in the chain, the scientist suggested that there are unequal compounds in the world that have different properties, but are completely identical in molecular composition. In other words, there is a phenomenon of isomerism.
With this position, the theory of the structure of organic compounds of A. M. Butlerov not only explained the essence of isomers and isomerism, but the scientist himself confirmed everything by practical experience.
So, for example, he synthesized an isomer of butane - isobutane. Then he predicted for pentane the existence of not one, but three isomers, based on the structure of the compound. And he synthesized them all, proving his case.
Disclosure of the third provision
The next point of the theory says that all atoms and molecules within the same compound are able to influence the properties of each other. The nature of the behavior of a substance in reactions of various types, the chemical and other properties exhibited, will depend on this.
Thus, on the basis of this provision, several differing in the type and structure of the functional defining group are distinguished.
The theory of the structure of organic compounds by A. M. Butlerov is summarized in almost all textbooks on organic chemistry. After all, it is she who is the basis of this section, the explanation of all the patterns on which molecules are built.
The Importance of Theory for Modernity
Certainly it is great. This theory allowed:
- combine and systematize all the factual material accumulated by the time of its creation;
- explain the patterns of structure, properties of various compounds;
- give a full explanation of the reasons for such a large variety of compounds in chemistry;
- gave rise to numerous syntheses of new substances based on the provisions of the theory;
- allowed the advancement of views, the development of atomic and molecular science.
Therefore, to say that the author of the theory of the structure of organic compounds, whose photo can be seen below, did a lot, is to say nothing. Butlerov can rightfully be considered the father of organic chemistry, the ancestor of its theoretical foundations.
His scientific vision of the world, the genius of thinking, the ability to foresee the result played a role in the final analysis. This man possessed colossal capacity for work, patience and tirelessly experimented, synthesized, and trained. I was wrong, but I always learned a lesson and made the right perspective conclusions.
Only such a set of qualities and business acumen, perseverance made it possible to achieve the desired effect.
Studying organic chemistry at school
In the course of secondary education, not much time is devoted to studying the basics of organics. Only one quarter of the 9th grade and the whole year of the 10th stage (according to the program of Gabrielyan O.S.). However, this time is enough for the guys to be able to study all the main classes of compounds, the features of their structure and nomenclature, and their practical significance.
The basis for starting the development of the course is the theory of the structure of organic compounds by A. M. Butlerov. Grade 10 is devoted to a full consideration of its provisions, and in the future - to their theoretical and practical confirmation in the study of each class of substances.
All substances that contain a carbon atom, in addition to carbonates, carbides, cyanides, thiocyanates and carbonic acid, are organic compounds. This means that they are able to be created by living organisms from carbon atoms through enzymatic or other reactions. Today, many organic substances can be synthesized artificially, which allows the development of medicine and pharmacology, as well as the creation of high-strength polymer and composite materials.
Classification of organic compounds
Organic compounds are the most numerous class of substances. There are about 20 types of substances here. They are different in chemical properties, differ in physical qualities. Their melting point, mass, volatility and solubility, as well as their state of aggregation under normal conditions, are also different. Among them:
- hydrocarbons (alkanes, alkynes, alkenes, alkadienes, cycloalkanes, aromatic hydrocarbons);
- aldehydes;
- ketones;
- alcohols (dihydric, monohydric, polyhydric);
- ethers;
- esters;
- carboxylic acids;
- amines;
- amino acids;
- carbohydrates;
- fats;
- proteins;
- biopolymers and synthetic polymers.
This classification reflects the features of the chemical structure and the presence of specific atomic groups that determine the difference in the properties of a substance. In general terms, the classification, which is based on the configuration of the carbon skeleton, which does not take into account the features of chemical interactions, looks different. According to its provisions, organic compounds are divided into:
- aliphatic compounds;
- aromatic substances;
- heterocyclic compounds.
These classes of organic compounds can have isomers in different groups of substances. The properties of the isomers are different, although their atomic composition may be the same. This follows from the provisions laid down by A. M. Butlerov. Also, the theory of the structure of organic compounds is the guiding basis for all research in organic chemistry. It is put on the same level with Mendeleev's Periodic Law.
The very concept of chemical structure was introduced by A. M. Butlerov. In the history of chemistry, it appeared on September 19, 1861. Previously, there were different opinions in science, and some scientists completely denied the existence of molecules and atoms. Therefore, there was no order in organic and inorganic chemistry. Moreover, there were no regularities by which it was possible to judge the properties of specific substances. At the same time, there were also compounds that, with the same composition, exhibited different properties.
The statements of A. M. Butlerov in many ways directed the development of chemistry in the right direction and created a solid foundation for it. Through it, it was possible to systematize the accumulated facts, namely, the chemical or physical properties of certain substances, the patterns of their entry into reactions, and so on. Even the prediction of ways to obtain compounds and the presence of some common properties became possible thanks to this theory. And most importantly, A. M. Butlerov showed that the structure of a substance molecule can be explained in terms of electrical interactions.
The logic of the theory of the structure of organic substances
Since, before 1861, many in chemistry rejected the existence of an atom or a molecule, the theory of organic compounds became a revolutionary proposal for the scientific world. And since A. M. Butlerov himself proceeds only from materialistic conclusions, he managed to refute the philosophical ideas about organic matter.
He managed to show that the molecular structure can be recognized empirically through chemical reactions. For example, the composition of any carbohydrate can be determined by burning a certain amount of it and counting the resulting water and carbon dioxide. The amount of nitrogen in the amine molecule is also calculated during combustion by measuring the volume of gases and releasing the chemical amount of molecular nitrogen.
If we consider Butlerov's judgments about the chemical structure, which depends on the structure, in the opposite direction, then a new conclusion suggests itself. Namely: knowing the chemical structure and composition of a substance, one can empirically assume its properties. But most importantly, Butlerov explained that in organic matter there is a huge number of substances that exhibit different properties, but have the same composition.
General provisions of the theory
Considering and investigating organic compounds, A. M. Butlerov deduced some of the most important patterns. He combined them into the provisions of the theory explaining the structure of chemicals of organic origin. The provisions of the theory are as follows:
- in the molecules of organic substances, atoms are interconnected in a strictly defined sequence, which depends on valence;
- chemical structure is the direct order according to which atoms are connected in organic molecules;
- the chemical structure determines the presence of the properties of an organic compound;
- depending on the structure of molecules with the same quantitative composition, different properties of the substance may appear;
- all atomic groups involved in the formation of a chemical compound have a mutual influence on each other.
All classes of organic compounds are built according to the principles of this theory. Having laid the foundations, A. M. Butlerov was able to expand chemistry as a field of science. He explained that due to the fact that carbon exhibits a valence of four in organic substances, the variety of these compounds is determined. The presence of many active atomic groups determines whether a substance belongs to a certain class. And it is precisely due to the presence of specific atomic groups (radicals) that physical and chemical properties appear.
Hydrocarbons and their derivatives
These organic compounds of carbon and hydrogen are the simplest in composition among all the substances of the group. They are represented by a subclass of alkanes and cycloalkanes (saturated hydrocarbons), alkenes, alkadienes and alkatrienes, alkynes (unsaturated hydrocarbons), as well as a subclass of aromatic substances. In alkanes, all carbon atoms are connected only by a single C-C bond, which is why not a single H atom can be built into the composition of the hydrocarbon.
In unsaturated hydrocarbons, hydrogen can be incorporated at the site of the double C=C bond. Also, the C-C bond can be triple (alkynes). This allows these substances to enter into many reactions associated with the reduction or addition of radicals. All other substances, for the convenience of studying their ability to enter into reactions, are considered as derivatives of one of the classes of hydrocarbons.
Alcohols
Alcohols are called organic chemical compounds more complex than hydrocarbons. They are synthesized as a result of enzymatic reactions in living cells. The most typical example is the synthesis of ethanol from glucose as a result of fermentation.
In industry, alcohols are obtained from halogen derivatives of hydrocarbons. As a result of the substitution of a halogen atom for a hydroxyl group, alcohols are formed. Monohydric alcohols contain only one hydroxyl group, polyhydric - two or more. An example of a dihydric alcohol is ethylene glycol. The polyhydric alcohol is glycerol. The general formula of alcohols is R-OH (R is a carbon chain).
Aldehydes and ketones
After alcohols enter into reactions of organic compounds associated with the elimination of hydrogen from the alcohol (hydroxyl) group, a double bond between oxygen and carbon closes. If this reaction takes place at the alcohol group located at the terminal carbon atom, then as a result of it, an aldehyde is formed. If the carbon atom with alcohol is not located at the end of the carbon chain, then the result of the dehydration reaction is the production of a ketone. The general formula of ketones is R-CO-R, aldehydes R-COH (R is the hydrocarbon radical of the chain).
Esters (simple and complex)
The chemical structure of organic compounds of this class is complicated. Ethers are considered as reaction products between two alcohol molecules. When water is cleaved from them, a compound of the R-O-R sample is formed. Reaction mechanism: elimination of a hydrogen proton from one alcohol and a hydroxyl group from another alcohol.
Esters are reaction products between an alcohol and an organic carboxylic acid. Reaction mechanism: elimination of water from the alcohol and carbon groups of both molecules. Hydrogen is split off from the acid (along the hydroxyl group), and the OH group itself is separated from the alcohol. The resulting compound is depicted as R-CO-O-R, where the beech R denotes radicals - the rest of the carbon chain.
Carboxylic acids and amines
Carboxylic acids are called special substances that play an important role in the functioning of the cell. The chemical structure of organic compounds is as follows: a hydrocarbon radical (R) with a carboxyl group (-COOH) attached to it. The carboxyl group can only be located at the extreme carbon atom, because the valency C in the (-COOH) group is 4.
Amines are simpler compounds that are derivatives of hydrocarbons. Here, any carbon atom has an amine radical (-NH2). There are primary amines in which the (-NH2) group is attached to one carbon (general formula R-NH2). In secondary amines, nitrogen combines with two carbon atoms (formula R-NH-R). Tertiary amines have nitrogen attached to three carbon atoms (R3N), where p is a radical, a carbon chain.
Amino acids
Amino acids are complex compounds that exhibit the properties of both amines and acids of organic origin. There are several types of them, depending on the location of the amine group in relation to the carboxyl group. Alpha amino acids are the most important. Here the amine group is located at the carbon atom to which the carboxyl group is attached. This allows you to create a peptide bond and synthesize proteins.
Carbohydrates and fats
Carbohydrates are aldehyde alcohols or keto alcohols. These are compounds with a linear or cyclic structure, as well as polymers (starch, cellulose, and others). Their most important role in the cell is structural and energetic. Fats, or rather lipids, perform the same functions, only they participate in other biochemical processes. Chemically, fat is an ester of organic acids and glycerol.
The first appeared at the beginning of the 19th century. radical theory(J. Gay-Lussac, F. Wehler, J. Liebig). Radicals were called groups of atoms that pass unchanged during chemical reactions from one compound to another. This concept of radicals has been preserved, but most of the other provisions of the theory of radicals turned out to be incorrect.
According to type theory(C. Gerard) all organic substances can be divided into types corresponding to certain inorganic substances. For example, R-OH alcohols and R-O-R ethers were considered as representatives of the H-OH type of water, in which hydrogen atoms are replaced by radicals. The theory of types created a classification of organic substances, some of the principles of which are currently applied.
The modern theory of the structure of organic compounds was created by the outstanding Russian scientist A.M. Butlerov.
The main provisions of the theory of the structure of organic compounds A.M. Butlerov
1. Atoms in a molecule are arranged in a certain sequence according to their valency. The valency of the carbon atom in organic compounds is four.
2. The properties of substances depend not only on which atoms and in what quantities are part of the molecule, but also on the order in which they are interconnected.
3. The atoms or groups of atoms that make up the molecule mutually influence each other, on which the chemical activity and reactivity of the molecules depend.
4. The study of the properties of substances allows you to determine their chemical structure.
The mutual influence of neighboring atoms in molecules is the most important property of organic compounds. This influence is transmitted either through a chain of single bonds or through a chain of conjugated (alternating) single and double bonds.
Classification of organic compounds is based on the analysis of two aspects of the structure of molecules - the structure of the carbon skeleton and the presence of functional groups.
organic compounds
Hydrocarbons Heterocyclic compounds
Limit- Nepre- Aroma-
ny efficient tic
Aliphatic Carbocyclic
Limit Unsaturated Alicyclic Aromatic
(Alkanes) (Cycloalkanes) (Arenas)
FROM P H 2 P+2 C P H 2 P FROM P H 2 P-6
End of work -
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Alkenes Alkadienes Alkynes
SpN2p SpN2p-2 SpN2p-2 Fig. 1. Classification of organic compounds by structure
The electronic structure of the carbon atom. Hybridization.
For the valence electron layer of the C atom, which is in the main subgroup of the fourth group of the second period of the Periodic Table of D. I. Mendeleev, the main quantum number n \u003d 2, side (orbitally
Related systems
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TOPIC 3. Chemical structure and isomerism of organic compounds
Isomerism of organic compounds. If two or more individual substances have the same quantitative composition (molecular formula), but differ from each other
Conformations of organic molecules
The rotation around the C–C s-bond is relatively easy, and the hydrocarbon chain can take different forms. Conformational forms easily pass into each other and therefore are not different compounds.
Conformations of cyclic compounds.
Cyclopentane. The five-membered ring in the planar form has bond angles of 108°, which is close to the normal value for the sp3-hybrid atom. Therefore, in planar cyclopentane, in contrast to the cycle
Configuration isomers
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General characteristics of the reactions of organic compounds.
Acidity and basicity of organic compounds. To assess the acidity and basicity of organic compounds, two theories are of greatest importance - the Bronsted theory and the theory
Bronsted bases are neutral molecules or ions that can accept a proton (proton acceptors).
Acidity and basicity are not absolute, but relative properties of compounds: acidic properties are found only in the presence of a base; basic properties - only in the presence of ki
General characteristics of reactions of organic compounds
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Selectivity of reactions
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radical reactions.
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Electrophilic addition reactions
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Reactions of nucleophilic substitution at the sp3-hybridized carbon atom: heterolytic reactions due to the polarization of the carbon-heteroatom s-bond (halopro
Reactions of nucleophilic substitution involving sp2-hybridized carbon atom.
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Reactions of nucleophilic substitution in the series of carboxylic acids.
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organic compounds.
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Carboxylic acids containing one carboxyl group in their composition are called monobasic, two - dibasic, etc. Dicarboxylic acids are white crystalline substances with
Amino alcohols
2-Aminoethanol (ethanolamine, colamine) - a structural component of complex lipids, is formed by opening the strained three-membered cycles of ethylene oxide and ethyleneimine with ammonia or water, respectively
Hydroxy and amino acids.
Hydroxy acids contain both hydroxyl and carboxyl groups in the molecule, amino acids - carboxyl and amino groups. Depending on the location of the hydroxy or amino group p
Oxoacids
Oxoacids are compounds containing both carboxyl and aldehyde (or ketone) groups. In accordance with this, aldehyde acids and keto acids are distinguished. The simplest aldehyde
Heterofunctional derivatives of benzene as drugs.
The last decades are characterized by the emergence of many new medicines and preparations. At the same time, some groups of previously known medicinal drugs continue to be of great importance.
TOPIC 10. Biologically important heterocyclic compounds
Heterocyclic compounds (heterocycles) are compounds that include one or more atoms other than carbon (heteroatoms) in the cycle. Heterocyclic systems underlie
TOPIC 11. Amino acids, peptides, proteins
Structure and properties of amino acids and peptides. Amino acids are compounds in the molecules of which both amino and carboxyl groups are simultaneously present. natural a-amine
Spatial structure of polypeptides and proteins
High-molecular polypeptides and proteins, along with the primary structure, are characterized by higher levels of organization, which are commonly called secondary, tertiary, and quaternary structures.
TOPIC 12. Carbohydrates: mono, di- and polysaccharides
Carbohydrates are divided into simple (monosaccharides) and complex (polysaccharides). Monosaccharides (monoses). These are heteropolyfunctional compounds containing a carbonyl and several g
TOPIC 13. Nucleotides and nucleic acids
Nucleic acids (polynucleotides) are biopolymers whose monomer units are nucleotides. A nucleotide is a three-component structure consisting of
Nucleosides.
Heterocyclic bases form N-glycosides with D-ribose or 2-deoxy-D-ribose. In nucleic acid chemistry, such N-glycosides are called nucleosides. D-ribose and 2-deoxy-D-ribose in the composition of p
Nucleotides.
Nucleotides are called nucleoside phosphates. Phosphoric acid usually esterifies the alcohol hydroxyl at C-5" or C-3" in a ribose or deoxyribose residue (the atoms of the nitrogenous base cycle are numbered
Steroids
Steroids are widely distributed in nature and perform a variety of functions in the body. To date, about 20,000 steroids are known; more than 100 of them are used in medicine. Steroids have
Steroid hormones
Hormones are biologically active substances that are formed as a result of the activity of the endocrine glands and take part in the regulation of metabolism and physiological functions in the body.
Sterols
As a rule, cells are very rich in sterols. Depending on the source of isolation, zoosterols (from animals), phytosterols (from plants), mycosterols (from fungi) and sterols of microorganisms are distinguished. AT
Bile acids
In the liver, sterols, in particular cholesterol, are converted into bile acids. The aliphatic side chain at C17 in bile acids, derivatives of the hydrocarbon cholane, consists of 5 carbon atoms
Terpenes and terpenoids
Under this name, a number of hydrocarbons and their oxygen-containing derivatives are combined - alcohols, aldehydes and ketones, the carbon skeleton of which is built from two, three or more isoprene units. themselves
vitamins
Vitamins are usually called organic substances, the presence of which in a small amount in the food of humans and animals is necessary for their normal functioning. This is a classic op
Fat soluble vitamins
Vitamin A refers to sesquiterpenes, found in butter, milk, egg yolk, fish oil; lard and margarine do not contain it. This is a growth vitamin; lack of it in food
Water Soluble Vitamins
At the end of the last century, thousands of sailors on Japanese ships suffered, and many of them died painful deaths from the mysterious beriberi disease. One of the mysteries of beriberi was that sailors on
