According to the basic structure, organic matter can be divided into three categories:
(1) Open-chain compounds, also known as aliphatic compounds, originally existed in oils and fats. Its structural feature is that carbon and carbon are connected to form an open chain.
(2) Carbocyclic compounds (containing rings composed entirely of carbon atoms) can be divided into two categories: alicyclic compounds (which can be regarded as closed-loop compounds in structure) and aromatic compounds (containing benzene rings).
(3) Heterocyclic compounds (rings containing carbon atoms and other elements).
Classification 2
A series of compounds composed of one or several "CH2" groups with similar structures and different molecular compositions are called homologous. Each member of the same series is called a homologue. The chemical properties of homologues are similar because of their similar structures. Their physical properties often change regularly with the increase of molecular weight.
Homologues are similar in structure, but differ in molecular composition by one or more "CH2" groups. Compounds with the same general formula are called homologues. Such as methane, ethane, propane and n-butane in alkane series are called homologues.
Hydrocarbon is an organic compound composed of carbon and hydrogen, also known as "hydrocarbon". According to the structure and nature, there are many kinds.
Can be classified as follows:
Open-chain hydrocarbons are hydrocarbons in which carbon atoms in open-chain hydrocarbons combine with each other to form chains without cyclic structure. According to the content of carbon and hydrogen in the molecule, chain hydrocarbons can be divided into saturated chain hydrocarbons (alkanes) and unsaturated chain hydrocarbons (olefins and alkynes).
Aliphatic hydrocarbons are also called "chain hydrocarbons". Because fat is a derivative of chain hydrocarbon, which is also called aliphatic hydrocarbon.
Saturated hydrocarbon Saturated hydrocarbon can be divided into chain saturated hydrocarbon, namely alkane (also called paraffin hydrocarbon) and another cyclic saturated hydrocarbon, namely cycloalkane (see closed chain hydrocarbon).
Alkanes are saturated chain hydrocarbons, also called paraffin hydrocarbons. The general formula is CnH2n+2(n≥ 1), and the hydrogen content in alkanes has reached saturation. The simplest alkane is methane, which is the main component of natural gas and biogas. The main sources of alkanes are oil, natural gas and biogas. Substitution reaction can occur, and methane can react with chlorine under illumination, and the product is ch3cl-ch2cl2-chcl3-ccl4.
The molecule of unsaturated hydrocarbon contains "C=C" or "C≡C". Such hydrocarbons can also be divided into unsaturated chain hydrocarbons and unsaturated cyclic hydrocarbons. Unsaturated chain hydrocarbons contain fewer hydrogen atoms than corresponding alkanes, which are chemically active and easy to add and polymerize. Unsaturated chain hydrocarbons can be divided into olefins and alkynes. Unsaturated cyclic hydrocarbons can be divided into cyclic olefins (such as cyclopentadiene) and cyclic alkynes (such as phenylacetylene).
Olefin molecules contain "C=C" hydrocarbons. According to the number of "C=C" in the molecule, it can be divided into monoolefins and diolefins. Monoolefin molecules contain a "C=C" with the general formula CnH2n, where n is ≥ 2. The most important monoolefin is ethylene H2C=CH2, followed by propylene CH3CH=CH2 and 0- butene OH3CH2CH=CH2. Monoolefins are short for olefins, and the main sources of olefins are petroleum and its pyrolysis products.
The diene system contains two "C=C" chain hydrocarbons or cyclic hydrocarbons. For example, 1, 3- butadiene. 2- methyl-1, 3- butadiene, cyclopentadiene, etc. The most important dienes contain * * * yoke double bond system, such as 1, 3- butadiene and 2- methyl-1, 3- butadiene, which are monomers of synthetic rubber.
Alkynes are unsaturated chain hydrocarbons with "C≡C" in the molecule. According to the number of carbon-carbon triple bonds in the molecule, it can be divided into monoacetylenes and polyacetylenes. The general formula of monoacetylene is CnHn-2, where n≥2. Alkynes and dienes are isomers. The simplest and most important alkyne is acetylene HC≡CH, which can be prepared by reacting calcium carbide with water.
Closed hydrocarbon is also called "cyclic hydrocarbon". Is a hydrocarbon with a cyclic structure. It can be divided into two categories, one is that alicyclic hydrocarbons (or aliphatic cycloalkanes) have aliphatic properties, and alicyclic hydrocarbons are divided into saturated cycloalkanes, where n≥3. Cycloalkanes and olefins are isomers. Cycloalkanes exist in some oils, and cycloolefins often exist in plant essential oils. Another kind of cyclic hydrocarbon is aromatic hydrocarbon, most of which have benzene ring structure and the properties of aromatic compounds.
Cycloalkanes are saturated alicyclic hydrocarbons in which carbon atoms are bonded to each other by single bonds. Tricyclic and tetracyclic cycloalkanes have poor stability and are easy to open rings under certain conditions. Cycloalkanes with more than five rings are relatively stable and their properties are similar to alkanes. Common cycloalkanes are cyclopropane, cyclobutane, cyclopentane and cyclohexane.
Aromatic hydrocarbons generally refer to hydrocarbons with benzene ring structure in their molecules. According to the number of benzene rings in the molecule and the connection mode between benzene rings, it can be divided into monocyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons and condensed aromatic hydrocarbons. The general formula of monocyclic aromatic hydrocarbon is CnH2n-6, where n is greater than or equal to 6, and benzene is an important monocyclic aromatic hydrocarbon.
Fused aromatic hydrocarbon molecules contain two or more benzene rings, which are connected by * * *, and two phases are used.
Heterocyclic compounds are compounds containing carbon atoms and other atoms such as oxygen, nitrogen and sulfur to form a cyclic structure. The heterocyclic ring with five protons and six atoms is relatively stable. Aromatic compounds are called aromatic heterocycles, and compounds in which one or more hydrogen atoms in hydrocarbon molecules are replaced by halogen atoms are called halogenated hydrocarbons. According to the different halogen atoms, it can be divided into fluorinated hydrocarbons, chlorinated hydrocarbons, brominated hydrocarbons and iodohydrocarbons. According to the number of halogen atoms in the molecule, it can be divided into monohalogenated hydrocarbons and polyhalogenated hydrocarbons. According to the different types of hydrocarbon groups, they can be divided into saturated halogenated hydrocarbons, unsaturated halogenated hydrocarbons, halogenated olefins, halogenated alkynes, halogenated aromatic hydrocarbons and so on. , such as chlorine CH3-CHBr-CH2Br, etc.
The product after one or several hydrogen atoms in alcohol hydrocarbon molecules are replaced by hydroxyl groups is called alcohol (if the hydrogen atoms on benzene rings are replaced by hydroxyl groups, the product belongs to phenols). According to the number of hydroxyl groups in alcohol molecules, it can be divided into monohydric alcohols, dihydric alcohols and trihydric alcohols. According to the different hydrocarbon groups in alcohol molecules, it can be divided into saturated alcohol, unsaturated alcohol and aromatic alcohol. Because of the different positions of carbon atoms connected with hydroxyl groups, they can be divided into primary alcohols such as
(CH3)3oh. Alcohols are generally neutral, lower alcohols are easily soluble in water, and polyols are sweet. The chemical properties of alcohols mainly include oxidation reaction, esterification reaction, dehydration reaction, reaction with halogen acid, reaction with active metal and so on.
Aromatic alcohol is a substance in which the hydrogen atom on the side bond of benzene ring in aromatic hydrocarbon molecule is replaced by hydroxyl group. Such as benzyl alcohol (also known as benzyl alcohol).
Phenols are compounds in which the hydrogen atom of benzene ring in phenol aromatic hydrocarbon molecules is replaced by hydroxyl group. According to the number of hydroxyl groups contained in phenol molecules, it can be divided into monohydric phenol, dihydric phenol and polyhydric phenol. If the solution changes color. Phenol is weakly acidic and can react with alkali to form phenolate. Benzene rings in phenol molecules are easily replaced by hydroxyl groups, such as halogenation, nitration and sulfonation.
A compound in which two hydrocarbon groups of an ether are connected by an oxygen atom is called an ether. It can be represented by the general formula R-O-R'. If R and R' are the same, they are called simple ethers, such as methyl ether CH3-O-CH3, ether C2H5-O-C2H5, etc. If R is different from R', it is called mixed ether, such as methyl ethyl ether CH3-O-C2H5. For example, the number of aldehyde groups in dihydric alcohol molecules can be divided into monoaldehyde, dihydric aldehyde and so on; According to the different alkyl groups in the molecule, it can be prepared by oxidizing the corresponding primary alcohol. Carbonyl groups in aldehydes can undergo addition reaction and are easily oxidized into corresponding carboxylic acids by weak oxidants such as Fehling reagent and Dolan reagent. Important aldehydes are formaldehyde and acetaldehyde.
The aldehyde formed by the direct connection of aldehyde group and benzene ring in aromatic aldehyde molecule is called aromatic aldehyde. Such as benzaldehyde.
Carboxylic acid hydrocarbon groups or compounds formed by connecting hydrogen atoms and carboxyl groups are called carboxylic acids. According to the number of carboxyl groups in carboxylic acid molecules, it can be divided into monoacid, dibasic acid and polybasic acid. Monobasic acids, such as acetic acid
Saturated acids such as propionic acid CH3CH2COOH, unsaturated acids such as acrylic acid CH2=CH-COOH, etc. Carboxylic acids can also be divided into fatty acids, alicyclic acids and aromatic acids. Among fatty acids, saturated fatty acids include stearic acid C 17H35COOH, etc.
Carboxylic acid derivatives Compounds in which the hydroxyl groups of carboxyl groups in carboxylic acid molecules are replaced by other atoms or atomic groups are called carboxylic acid derivatives. Such as acid halides, amides, anhydrides, and the like.
Compounds formed by substitution of hydroxyl groups on carboxyl groups in acyl halide carboxylic acid molecules by halogen atoms, etc.
The hydroxyl group on the carboxyl group in the amide carboxylic acid molecule is replaced by amino -NH2 or substituted amino group.
Anhydride is a compound formed by dehydration between monocarboxylic acid molecules of two molecules or dehydration inside dicarboxylic acid molecules, which is called anhydride. For example, two acetic acid molecules lose one water molecule to form acetic anhydride (CH3-
Compounds in which hydroxyl groups on carboxyl groups in ester carboxylic acid molecules are replaced by alkoxy groups -O-R' are called
Oils and fats are the general name of higher fatty acid glycerides. The liquid at room temperature is called oil, and the solid is called fat. It can be expressed by the general formula: if R, R' and R "are the same, it is called monoglyceride; If r, r' and r "are different, they are called mixed glycerides. Natural oils and fats are mostly mixed glycerides.
Nitro compound is a compound formed by replacing hydrogen atom in hydrocarbon molecule with nitro -NO2, which can be represented by the general formula R-NO2, and R can be alkyl or benzene ring. Such as nitroethane CH3CH2NO2,
Amines are organic compounds formed by replacing hydrogen atoms in ammonia molecules with hydrocarbon groups. According to the hydrocarbon structure, it can be divided into aliphatic amines such as methylamine CH3NH2, dimethylamine CH3-NH-CH3 and aromatic amines such as aniline C6H5-NH2 and diphenylamine (C6H5)2NH. According to the number of amino groups, it can be divided into monoamines, diamines and polyamines. Monoamines such as ethylamine CH3CH2NH2, diamines such as ethylenediamine H2N-CH2-CH2-NH2, and polyamines such as hexamethylenetetramine (C6H2)6N4. Amines are mostly weakly alkaline and can react with acids to form salts. Aniline is an important substance in amines, and it is also the raw material for synthesizing dyes and drugs.
Nitrile is a compound in which a hydrocarbon group is attached to a cyano group (-CN). The general formula is R-CN, such as acetonitrile CH3CN.
Diazo compounds are mostly organic compounds, the general formula is R-N2-X, and there is a diazo compound in its molecule, among which aromatic diazonium salt is the most important. It has chemical activity and is an intermediate for preparing azo dyes.
Organic compounds containing azo groups (-N=N-) in the molecule. It is represented by the general formula R-N=N-R, where R is a hydrocarbon group, azo compounds all have colors, and some of them can also be used as dyes. It can also be used as pigment.
The compound formed by substituting sulfonic acid group -SO3H for hydrogen atom in sulfonic acid hydrocarbon molecule can be represented by RSO3H. The preparation of aliphatic sulfonic acid is usually indirect, while aromatic sulfonic acid can be directly prepared by sulfonation reaction. Sulfonic acid is a strong acid, which is easily soluble in water. Aromatic sulfonic acid is an important intermediate for the synthesis of dyes and drugs.
Amino acids are compounds in which hydrogen atoms on hydrocarbon groups in carboxylic acid molecules are replaced by amino groups. According to the position of amino substitution, it can be divided into α-amino acid, β-amino acid and γ-amino acid. The amino group in α -amino acid is on the carbon atom adjacent to hydroxyl group. α -amino acid is the basic unit of protein. Protein can obtain more than 20 kinds of α -amino acids through hydrolysis, such as glycine, alanine and glutamic acid. , most of which are L-type α -amino acids. Among the amino acids needed by human body, those supplied by protein in food, such as lysine, tryptophan, phenylalanine and threonine, are called "essential amino acids", while glycine, serine, alanine and glutamic acid can be transformed from other organic substances in human body, so they are called "non-essential amino acids".
Peptide is a compound formed by the condensation of amino group in one amino acid with carboxyl group in another amino acid and the loss of water molecules. A peptide formed by two amino acid molecules is called dipeptide, such as two amino groups.
Polypeptide is formed by condensation of multiple α -amino acid molecules to eliminate water molecules, which contains multiple peptide bonds-
Protein is also called prion. Generally, the molecular weight is greater than 10000. Protein is the main component of organisms and the foundation of life activities. The composition, arrangement order and three-dimensional structure of amino acids in various protein are different. At present, many amino acid sequences and three-dimensional structures of protein have been clarified. Protein can be divided into fibrous protein and globular proteins according to its molecular shape. Fibrin, such as silk, hair, hair, skin, horns, hooves, etc. Globulins such as enzymes, protein hormones, etc. According to solubility, it can be divided into albumin, globulin, gliadin and insoluble hard protein. According to the composition, it can be divided into simple protein and compound protein. Simple protein is composed of amino acids, and complex protein is formed by combining simple protein with other substances, such as protein and nucleic acid to form nucleic acid protein, protein and sugar to form glycoprotein, and protein and heme to form hemoglobin.
Sugar is also called carbohydrate. Polyhydroxy aldehyde or polyhydroxy ketone and compound which can be hydrolyzed to produce polyhydroxy aldehyde or polyhydroxy ketone. Sugar can be divided into monosaccharide, oligosaccharide and polysaccharide. Generally, the ratio of the number of hydrogen atoms to the number of oxygen atoms in sugar is 2: 1, but formaldehyde CH2O is not sugar. Rhamnose: C6H 12O5 belongs to saccharides.
Monosaccharide is the simplest sugar that cannot be hydrolyzed, such as glucose (aldose)
When oligosaccharides are hydrolyzed, they can generate 2 ~ 10 monosaccharides, which are called oligosaccharides. Among them, disaccharides are the most important, such as sucrose, maltose and lactose.
Polysaccharide is also called polysaccharide. When a molecule of polysaccharide is hydrolyzed, it can generate more than 10 monosaccharides, which are called polysaccharides, such as starch and cellulose, and can be represented by the general formula (C6H 10O5) n, where n can be hundreds to thousands.
Polymer compounds are also called "polymer compounds" or "polymers". The molecular weight can be as high as thousands or even millions. It can be divided into natural polymer compounds and synthetic polymer compounds. Protein, nucleic acid, starch, cellulose, natural rubber and other natural polymer compounds. Synthetic polymer compounds, such as synthetic rubber, synthetic resin, synthetic fiber, plastic, etc. According to the structure, it can be divided into chain-like linear polymers compounds (such as rubber, fiber and thermoplastic) and network-like bulk polymer compounds (such as phenolic plastics and vulcanized rubber). According to the different reactions in the synthesis process, synthetic polymer compounds can be divided into addition polymers and condensation polymers. Addition polymer is a high molecular compound produced by addition polymerization. Such as polyethylene, polyvinyl chloride and polypropylene. Polycondensate is a polymer compound produced by polycondensation reaction. Such as phenolic plastic, nylon 66, etc.