Organic compounds and their classification. organic compounds

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 valency;
• 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.

There are many organic compounds, but among them there are compounds with common and similar properties. Therefore, they are all classified according to common characteristics, combined into separate classes and groups. The classification is based on hydrocarbons – compounds that are made up of only carbon and hydrogen atoms. The rest of the organic matter is "Other Classes of Organic Compounds".

Hydrocarbons are divided into two broad classes: acyclic and cyclic compounds.

Acyclic compounds (fatty or aliphatic) – compounds whose molecules contain an open (not closed in a ring) unbranched or branched carbon chain with single or multiple bonds. Acyclic compounds are divided into two main groups:

saturated (limiting) hydrocarbons (alkanes), in which all carbon atoms are interconnected only by simple bonds;

unsaturated (unsaturated) hydrocarbons, in which between carbon atoms, in addition to single simple bonds, there are also double and triple bonds.

Unsaturated (unsaturated) hydrocarbons are divided into three groups: alkenes, alkynes and alkadienes.

Alkenes(olefins, ethylene hydrocarbons) – acyclic unsaturated hydrocarbons that contain one double bond between carbon atoms form a homologous series with the general formula C n H 2n . The names of alkenes are formed from the names of the corresponding alkanes with the suffix "-an" replaced by the suffix "-en". For example, propene, butene, isobutylene or methylpropene.

Alkynes(acetylene hydrocarbons) – hydrocarbons that contain a triple bond between carbon atoms form a homologous series with the general formula C n H 2n-2 . The names of alkenes are formed from the names of the corresponding alkanes with the suffix "-an" replaced by the suffix "-in". For example, ethin (acylene), butin, peptin.

Alkadienes – organic compounds that contain two carbon-carbon double bonds. Depending on how the double bonds are arranged relative to each other, dienes are divided into three groups: conjugated dienes, allenes and dienes with isolated double bonds. Typically, dienes include acyclic and cyclic 1,3-dienes, forming with the general formulas C n H 2n-2 and C n H 2n-4 . Acyclic dienes are structural isomers of alkynes.

Cyclic compounds, in turn, are divided into two large groups:

1. carbocyclic compounds – compounds whose rings consist only of carbon atoms; Carbocyclic compounds are subdivided into alicyclic – saturated (cycloparaffins) and aromatic;
2. heterocyclic compounds – compounds whose cycles consist not only of carbon atoms, but of atoms of other elements: nitrogen, oxygen, sulfur, etc.

In molecules of both acyclic and cyclic compounds hydrogen atoms can be replaced by other atoms or groups of atoms, thus, by introducing functional groups, derivatives of hydrocarbons can be obtained. This property further expands the possibilities of obtaining various organic compounds and explains their diversity.

The presence of certain groups in the molecules of organic compounds determines the generality of their properties. This is the basis for the classification of derivatives of hydrocarbons.

"Other classes of organic compounds" include the following:

Alcohols are obtained by replacing one or more hydrogen atoms with hydroxyl groups – Oh. It is a compound with the general formula R – (OH) x, where x – number of hydroxyl groups.

Aldehydes contain an aldehyde group (C = O), which is always at the end of the hydrocarbon chain.

carboxylic acids contain one or more carboxyl groups – COOH.

Esters – derivatives of oxygen-containing acids, which are formally the products of substitution of hydrogen atoms of hydroxides – OH acid function per hydrocarbon residue; are also considered as acyl derivatives of alcohols.

Fats (triglycerides) – natural organic compounds, full esters of glycerol and monocomponent fatty acids; belong to the class of lipids. Natural fats contain three linear acid radicals and usually an even number of carbon atoms.

Carbohydrates – organic substances containing a straight chain of several carbon atoms, a carboxyl group and several hydroxyl groups.

Amines contain an amino group – NH2

Amino acids– organic compounds, the molecule of which simultaneously contains carboxyl and amine groups.

Squirrels – high-molecular organic substances, which consist of alpha-amino acids connected in a chain by a peptide bond.

Nucleic acids – high-molecular organic compounds, biopolymers formed by nucleotide residues.

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In the past, scientists divided all substances in nature into conditionally inanimate and living ones, including the animal and plant kingdoms among the latter. Substances of the first group are called mineral. And those that entered the second, began to be called organic substances.

What is meant by this? The class of organic substances is the most extensive among all chemical compounds known to modern scientists. The question of which substances are organic can be answered as follows - these are chemical compounds that include carbon.

Please note that not all carbon-containing compounds are organic. For example, corbides and carbonates, carbonic acid and cyanides, carbon oxides are not among them.

Why are there so many organic substances?

The answer to this question lies in the properties of carbon. This element is curious in that it is able to form chains from its atoms. Moreover, the carbon bond is very stable.

In addition, in organic compounds, it exhibits a high valence (IV), i.e. the ability to form chemical bonds with other substances. And not only single, but also double and even triple (otherwise - multiples). As the bond multiplicity increases, the chain of atoms becomes shorter, and the bond stability increases.

And carbon is endowed with the ability to form linear, flat and three-dimensional structures.

That is why organic substances in nature are so diverse. You can easily check it yourself: stand in front of a mirror and carefully look at your reflection. Each of us is a walking textbook on organic chemistry. Think about it: at least 30% of the mass of each of your cells is organic compounds. The proteins that built your body. Carbohydrates, which serve as "fuel" and a source of energy. Fats that store energy reserves. Hormones that control organ function and even your behavior. Enzymes that start chemical reactions within you. And even the "source code," the strands of DNA, are all carbon-based organic compounds.

Composition of organic substances

As we said at the very beginning, the main building material for organic matter is carbon. And practically any elements, combining with carbon, can form organic compounds.

In nature, most often in the composition of organic substances are hydrogen, oxygen, nitrogen, sulfur and phosphorus.

The structure of organic substances

The diversity of organic substances on the planet and the diversity of their structure can be explained by the characteristic features of carbon atoms.

You remember that carbon atoms are able to form very strong bonds with each other, connecting in chains. The result is stable molecules. The way carbon atoms are connected in a chain (arranged in a zigzag pattern) is one of the key features of its structure. Carbon can combine both into open chains and into closed (cyclic) chains.

It is also important that the structure of chemicals directly affects their chemical properties. A significant role is also played by how atoms and groups of atoms in a molecule affect each other.

Due to the peculiarities of the structure, the number of carbon compounds of the same type goes to tens and hundreds. For example, we can consider hydrogen compounds of carbon: methane, ethane, propane, butane, etc.

For example, methane - CH 4. Such a combination of hydrogen with carbon under normal conditions is in a gaseous state of aggregation. When oxygen appears in the composition, a liquid is formed - methyl alcohol CH 3 OH.

Not only substances with different qualitative composition (as in the example above) exhibit different properties, but substances of the same qualitative composition are also capable of this. An example is the different ability of methane CH 4 and ethylene C 2 H 4 to react with bromine and chlorine. Methane is capable of such reactions only when heated or under ultraviolet light. And ethylene reacts even without lighting and heating.

Consider this option: the qualitative composition of chemical compounds is the same, the quantitative is different. Then the chemical properties of the compounds are different. As in the case of acetylene C 2 H 2 and benzene C 6 H 6.

Not the last role in this variety is played by such properties of organic substances, "tied" to their structure, as isomerism and homology.

Imagine that you have two seemingly identical substances - the same composition and the same molecular formula to describe them. But the structure of these substances is fundamentally different, hence the difference in chemical and physical properties. For example, the molecular formula C 4 H 10 can be written for two different substances: butane and isobutane.

We are talking about isomers- compounds that have the same composition and molecular weight. But the atoms in their molecules are located in a different order (branched and unbranched structure).

Concerning homology- this is a characteristic of such a carbon chain in which each next member can be obtained by adding one CH 2 group to the previous one. Each homologous series can be expressed by one general formula. And knowing the formula, it is easy to determine the composition of any of the members of the series. For example, methane homologues are described by the formula C n H 2n+2 .

As the “homologous difference” CH 2 is added, the bond between the atoms of the substance is strengthened. Let's take the homologous series of methane: its first four members are gases (methane, ethane, propane, butane), the next six are liquids (pentane, hexane, heptane, octane, nonane, decane), and then substances in the solid state of aggregation follow (pentadecane, eicosan, etc.). And the stronger the bond between carbon atoms, the higher the molecular weight, boiling and melting points of substances.

What classes of organic substances exist?

Organic substances of biological origin include:

• proteins;
• carbohydrates;
• nucleic acids;
• lipids.

The first three points can also be called biological polymers.

A more detailed classification of organic chemicals covers substances not only of biological origin.

The hydrocarbons are:

• acyclic compounds:
  • saturated hydrocarbons (alkanes);
  • unsaturated hydrocarbons:
    • alkenes;
    • alkynes;
    • alkadienes.
• cyclic compounds:
  • carbocyclic compounds:
    • alicyclic;
    • aromatic.
  • heterocyclic compounds.

There are also other classes of organic compounds in which carbon combines with substances other than hydrogen:

• alcohols and phenols;
• aldehydes and ketones;
• carboxylic acids;
• esters;
• lipids;
• carbohydrates:
  • monosaccharides;
  • oligosaccharides;
  • polysaccharides.
  • mucopolysaccharides.
• amines;
• amino acids;
• proteins;
• nucleic acids.

Formulas of organic substances by classes

Examples of organic substances

As you remember, in the human body, various kinds of organic substances are the basis of the foundations. These are our tissues and fluids, hormones and pigments, enzymes and ATP, and much more.

In the bodies of humans and animals, proteins and fats are prioritized (half of the dry weight of an animal cell is protein). In plants (about 80% of the dry mass of the cell) - for carbohydrates, primarily complex - polysaccharides. Including for cellulose (without which there would be no paper), starch.

Let's talk about some of them in more detail.

For example, about carbohydrates. If it were possible to take and measure the masses of all organic substances on the planet, it would be carbohydrates that would win this competition.

They serve as a source of energy in the body, are building materials for cells, and also carry out the supply of substances. Plants use starch for this purpose, and glycogen for animals.

In addition, carbohydrates are very diverse. For example, simple carbohydrates. The most common monosaccharides in nature are pentoses (including deoxyribose, which is part of DNA) and hexoses (glucose, which is well known to you).

Like bricks, at a large construction site of nature, polysaccharides are built from thousands and thousands of monosaccharides. Without them, more precisely, without cellulose, starch, there would be no plants. Yes, and animals without glycogen, lactose and chitin would have a hard time.

Let's look carefully at squirrels. Nature is the greatest master of mosaics and puzzles: from just 20 amino acids, 5 million types of proteins are formed in the human body. Proteins also have many vital functions. For example, construction, regulation of processes in the body, blood coagulation (there are separate proteins for this), movement, transport of certain substances in the body, they are also a source of energy, in the form of enzymes they act as a catalyst for reactions, provide protection. Antibodies play an important role in protecting the body from negative external influences. And if a discord occurs in the fine tuning of the body, antibodies, instead of destroying external enemies, can act as aggressors to their own organs and tissues of the body.

Proteins are also divided into simple (proteins) and complex (proteins). And they have properties inherent only to them: denaturation (destruction, which you have noticed more than once when you boiled a hard-boiled egg) and renaturation (this property is widely used in the manufacture of antibiotics, food concentrates, etc.).

Let's not ignore and lipids(fats). In our body, they serve as a reserve source of energy. As solvents, they help the course of biochemical reactions. Participate in the construction of the body - for example, in the formation of cell membranes.

And a few more words about such curious organic compounds as hormones. They are involved in biochemical reactions and metabolism. These small hormones make men men (testosterone) and women women (estrogen). They make us happy or sad (thyroid hormones play an important role in mood swings, and endorphins give a feeling of happiness). And they even determine whether we are “owls” or “larks”. Whether you're ready to study late or prefer to get up early and do your homework before school, it's not just your daily routine that decides, but some adrenal hormones as well.

Conclusion

The world of organic matter is truly amazing. It is enough to delve into its study just a little to take your breath away from the feeling of kinship with all life on Earth. Two legs, four or roots instead of legs - we are all united by the magic of mother nature's chemical laboratory. It causes carbon atoms to join in chains, react and create thousands of such diverse chemical compounds.

You now have a short guide to organic chemistry. Of course, not all possible information is presented here. Some points you may have to clarify on your own. But you can always use the route we have planned for your independent research.

You can also use the definition of organic matter, classification and general formulas of organic compounds and general information about them in the article to prepare for chemistry classes at school.

Tell us in the comments which section of chemistry (organic or inorganic) you like best and why. Don't forget to "share" the article on social networks so that your classmates can also use it.

Please report if you find any inaccuracy or error in the article. We are all human and we all make mistakes sometimes.

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Topic: CLASSIFICATION OF ORGANIC SUBSTANCES, BASIS OF THE NOMENCLATURE OF ORGANIC COMPOUNDS

Lesson Objectives:

educational: Form the concepts of isomerism, structural formula, isomers. To acquaint with the principles of classifying organic compounds according to the structure of the carbon chain and according to functional groups, and on this basis to give an initial overview of the main classes of organic compounds. To give a general idea of ​​the basic principles for the formation of the names of organic compounds according to the international nomenclature.

educational: Formation of a scientific picture of the world, education of a sense of patriotism on the example of Butlerov.

developing: To develop the ability of students to compare, generalize, draw an analogy.

Lesson type: combined lesson

Management methods:

are common: explanatory and illustrative

private: verbal-visual

specific: conversation

Equipment: classification scheme for organic compounds

1. Organizational moment - 5 minutes

2.Checking homework - 25 min

3.Explanation and consolidation of new material - 55 min

4. Homework - 3 min

5. The results of the lesson - 2 minutes

1. Organizational moment: Greetings, attendance check.

2. Checking homework

? what is a sigma bond?

what is the relationship of pi?

Name the mechanisms of chemical bond breaking

3.Explanation of the new material:

In the last lesson, we talked about how large the number of known organic compounds is. Even an experienced chemist can easily drown in this boundless ocean. Therefore, scientists always strive to classify any set "on the shelves", to put things in order in their economy. By the way, it does not prevent each of us from doing this with our own things, so that at any time we know where everything is.

Substances can be classified according to various criteria, for example, according to composition, structure, properties, application - according to such a familiar logical system of signs. Since the composition of all organic compounds includes carbon atoms, then, obviously, the order of their connection, i.e., the structure, can serve as the most important feature of the classification of organic substances. On this basis, all organic substances are divided into groups depending on which backbone (skeleton) form carbon atoms, whether this backbone includes any other atoms, except for carbon.

Let's look at this classification in more detail using the following scheme:

carbon atoms, connecting with each other, can form chains of various lengths. If such a chain is not closed, the substance belongs to the group acyclic(non-cyclic) compounds. A closed chain of carbon atoms allows you to name a substance cyclic. Carbon atoms in the chain can be connected both by simple (single) and double, triple (multiple) bonds. If a molecule has at least one multiple carbon-carbon bond, it is called unlimited or unsaturated otherwise - limiting (saturated). If only carbon atoms make up a closed chain of a cyclic substance, it is called carbocyclic. However, instead of one or more carbon atoms in the cycle, there may be atoms of other elements, such as nitrogen, oxygen, sulfur. They are sometimes called heteroatoms and the connection is heterocyclic. In the group of carbocyclic substances there is a special “shelf” on which substances with a special arrangement of double and single bonds in the cycle are located. one such substance is benzene. Benzene, its closest and distant "relatives" are called aromatic substances, and the remaining carbocyclic compounds - alicyclic.

The classification is based on the structure of the molecule.

Acyclic compounds - compounds with an open (open) chain of carbon atoms. Such compounds are also referred to as aliphatic compounds or fatty compounds.

Limit connections - compounds containing single bonds.

Unsaturated compounds - compounds in which double or triple (multiple) bonds are present.

Cyclic compounds - compounds in which carbon atoms form cycles are carbocyclic and heterocyclic.

Carbocyclic - cyclic compounds formed only by carbon atoms are alicyclic and aromatic.

Heterocyclic compounds - cycles, which, in addition to carbon atoms, also include other atoms - heteroatoms (nitrogen, sulfur, oxygen)

Main classes of organic compounds

hydrocarbons - the simplest organic compounds, which include only carbon and hydrogen. They are saturated (alkanes), unsaturated (alkenes, alkynes, alkadienes, etc.) and aromatic (arenes).

When replacing hydrogen atoms in a hydrocarbon with other atoms or groups of atoms -functional groups - numerous classes of organic compounds are formed (alcohols, aldehydes, ketones, carboxylic acids, esters, amines, amino acids, etc.).

Let's write a table:

Nomenclature of organic substances

Nomenclature is a system of names usedin any science.

At the dawn of the development of organic chemistry, there were quite a few known substances of living nature. Scientists of that time could afford to come up with their own name for each substance, which often did not even fit into one word, and even more than one. Such names most often reflected the origin of the substance or its most striking property: acetic acid, bitter almond oil (benzaldehyde), glycerin (from Greek - sweet) , formaldehyde (from Latin - ant). Such names are called trivial. Trivial nomenclature - Historical names. They are widely used in chemistry to designate substances of a simple structure. With the accumulation of experimental material, it became clear that many substances have similar properties, that is, they belong to the same group (class) of compounds. All substances of this class began to distribute similar names of substances.

The number of known organic compounds is growing exponentially. It became difficult for chemists from different countries to communicate, since the same substances had different names, and one name meant several substances. There were great difficulties with the names of complex molecules. To solve this problem, chemists from all countries that are members of the International Union of Pure and Applied Chemistry (IUPAC) created a special committee that developed the foundations the same for all organic substances nomenclature. This nomenclature is called international or IUPAC nomenclature.

In order to be able to use it, you need to know well the names of the first representatives of the homologous series of saturated hydrocarbons (from ethane to decane) and several of the simplest saturated radicals (methyl, ethyl, propyl).

Let's write a table:

Basic principles of IUPAC nomenclature

1. The basis of the name of the substance is the name of the limitth hydrocarbon with the same number of carbon atoms as in the longest chain of the acyclic molecule.

Position of substituent, functional groups and multipleslinks in the main chain are indicated by numbers.

Substituents, functional groups and multiple bonds are indicated in the name using prefixes (the same prefixes, but specific, chemical ones) and suffixes.

When writing the name, all numbers are separated from each other.each other with commas, and from letters with hyphens.

CH 3 - CH \u003d CH - CH 3 H 2 N - CH 2 - COOH

CH 3 - CH 2 - CH 2 - CH 2 _ - CH 3 CH 3 - CH 2 - CH 2 - OH

CH 3 - CH 2 - NH 2 CH 3 - CH 2 - CH 2 - NO 2

Consider the isomerism of organic substances

? What is isomerism?

Example: CH 3 - CH 2 - CH 2 - CH 2 - CH 3 CH 3 - CH 2 (CH 3) - CH 2 - CH 3

3. Homework:

L.A. Tsvetkov "Organic Chemistry - 10" §3;

4. Results: Thus, today we got acquainted with the classification, nomenclature and isomerism of organic substances. Lesson grades.

Purpose of the lecture: familiarity with the classification and nomenclature of organic compounds

Plan:

1. Subject and tasks of organic chemistry. Its significance for pharmacy.

2. Classification of organic compounds.

3. Principles of trivial and rational nomenclature.

4. Principles of IUPAC nomenclature.

Subject and tasks of organic chemistry.

Organic chemistry is a branch of chemistry devoted to the study of the structure, methods of synthesis and chemical transformations of hydrocarbons and their functional derivatives.

The term "organic chemistry" was first introduced by the Swedish chemist Jens Jakob Berzellius in 1807.

Due to the peculiarities of their structure, organic substances are very numerous. Today their number reaches 10 million.

At present, the state of organic chemistry is such that it makes it possible to scientifically plan and carry out the synthesis of any complex molecules (proteins, vitamins, enzymes, drugs, etc.).

Organic chemistry is closely related to pharmacy. It allows the isolation of individual medicinal substances from plant and animal raw materials, synthesizes and purifies medicinal raw materials, determines the structure of the substance and the mechanism of chemical action, and allows determining the authenticity of a particular drug. Suffice it to say that 95% of medicines are organic in nature.

Classification of organic compounds

In the classification, two most important features are taken as a basis: structure carbon skeleton and the presence in the molecule functional groups.

According to the structure of the carbon skeleton, organic. compounds are divided into three large groups.

I Acyclic(aliphatic) compounds having an open carbon chain, both straight and branched.

The parent compounds in organic chemistry are recognized hydrocarbons consisting only of carbon and hydrogen atoms. A variety of organic compounds can be considered as derivatives of hydrocarbons obtained by introducing functional groups into them.

A functional group is a structural fragment of a molecule that is characteristic of a given class of organic compounds and determines its chemical properties.

For example, the properties of alcohols are determined by the presence of a hydroxo group ( - HE), properties of amines - amino groups ( - NH2), carboxylic acids by the presence of a carboxyl group in the molecule (- UNSD) and so on.

Table 1. Main classes of organic compounds

This classification is important because the functional groups largely determine the chemical properties of this class of compounds.

If the compounds contain several functional groups and they are the same, then such compounds are called polyfunctional (CH 2 HE- CH HE- CH 2 HE- glycerol), if the molecule contains different functional groups, then this heterofunctional compound (CH 3 - CH ( HE)- UNSD- lactic acid). Heterofunctional compounds can be immediately attributed to several classes of compounds.