Chemical fortune telling _ chemical arithmetic

Customary nomenclature, also known as common nomenclature, is suitable for alkanes with simple structure. The naming method is as follows:

(1) A straight-chain alkane is represented by "n" and named as normal alkane according to the number of carbon atoms.

If the number of carbon atoms is 1 ~ 10, it is represented by the names of heavenly stems A, B, C, D, E, F, G, N, N and C, and if the number of carbon atoms is greater than 10, it is represented by lowercase chinese numerals.

The word "positive" can also be represented by "n-" (n is taken from the first letter of "normal" in English), but it can often be omitted.

(2) Using "hetero" to represent alkanes with (ch)ch- structure at the end.

The word "different" can also mean "I-"or "different".

(3) The term "novel" is used to indicate alkanes with 5 or 6 carbon atoms with a (CH)C- structure at the end.

The word "new" can also be expressed by "new". There are many kinds of organic compounds, even if the molecular formula is the same, there are different isomers. If there is no complete naming method to distinguish each compound, it will cause great confusion in the literature. Therefore, it is an important content of organic chemistry to study the naming of each compound carefully. IUPAC nomenclature. The nomenclature of China was formulated by chinese chemical society in combination with the naming principles of IUPAC and the characteristics of China characters. 1960 revised the systematic naming principle of organic chemistry, and 1980 supplemented it, and published an updated version of the naming principle of organic chemistry.

Nomenclature of alkanes

Hydrocarbons with a single bond between carbon and hydrocarbons are called alkanes, acyclic alkanes are called alkanes, and cycloalkanes are called cycloalkanes. Alkane is the parent compound of organic matter, so learn the naming of alkane first.

Nomenclature of alkanes

Nomenclature of (1) linear alkanes

The name of straight-chain alkane is "carbon number+alkane". When the number of carbon atoms is 1 ~ 10, it is expressed by tiangan-a, b, c, d, e, f, g, n and d in turn. When the number of carbon atoms exceeds 10, it is expressed by numbers. For example, straight-chain alkanes with six carbons are called hexane. Fourteen-carbon straight-chain alkanes are called tetradecane. The English name of alkane is alkane, and the suffix is ane.

(2) Naming of Branched Alkanes

Branched alkanes are called branched alkanes.

(a) the order of carbon atoms

The following compounds contain four different carbon atoms:

(1) is connected to a carbon, which is a primary carbon atom, and is represented by 1 (or primary carbon). Hydrogen at 1℃ is called primary hydrogen and is represented by1h.

(2) connected with two carbons, it is secondary carbon, which is represented by 2 (or secondary carbon), and the hydrogen at 2 C is called secondary hydrogen, which is represented by.

(3) tertiary carbon, which is connected with three carbons, is represented by 3 (or tertiary carbon), and the hydrogen on 3 C is called tertiary hydrogen, which is represented by 3 H. ..

④ It is connected with four carbons, and it is a four-level carbon atom, which is represented by 4 (or quaternarycarbon).

(2) the name of the alkyl group

After removing a hydrogen atom from an alkane, the remaining part is called an alkyl group. The English name is alkyl, that is, the suffix -ane of alkane is changed to -yl. Alkyl groups can be named by common nomenclature or systematic nomenclature.

The systematic nomenclature of alkyl groups is suitable for all kinds of situations. Its naming method is: the carbon without hydrogen atom is positioned as 1, and the longest chain is selected as the main chain of alkyl, starting from the carbon at 1, and the groups not on the main chain of alkyl are used as the substituents of the main chain. When writing the name, write the number and name of the substituent on the main chain before the name of the main chain.

(iii) Sequential rules

Various groups in organic compounds can be arranged orderly according to certain rules, which is called Cahn-Ingold-Prdog sequence. The main contents are as follows:

① Monoatomic substituents are arranged according to atomic number (atmmc number), with the largest atomic number in front and the smallest atomic number in the back. The order of common elements in organic compounds is as follows:

Me & GTBR & GTCL & GTS>P>F>O>N>C>D>H

Among isotopes (isotopes), the order of high quality ranks first.

(2) If the first atom of two polyatomic groups is the same, compare the other atoms connected with it. When comparing, arrange by atomic number, the largest is the same first, and the smallest is in the middle.

③ Groups containing double bonds or triple bonds can be considered to contain two or three identical atoms.

(4) If the number of bonds of atoms participating in the comparison sequence is less than four, an appropriate amount of virtual atoms with atomic number zero can be added, and the order of virtual atoms is placed last.

(four) the basic format of the name

The basic format of systematic naming of organic compounds is as follows: configuration+substituent+parent R-S; d-L； z-E； Cis-trans substituent position number+number+name (when there are multiple substituents, the order is determined according to the cis-trans rule, and the smallest one comes first; English is arranged in alphabetical order) functional group number+name (no functional group is involved) (ⅴ) naming principles and steps.

When naming, you must first determine the main chain. When naming alkanes, the principle of determining the main chain is: consider the chain length first, and the long one takes precedence. If there are two or more longest chains with the same length, the main chain is determined according to the number of side chains, and the most one takes precedence. If it is still impossible to separate which chain is the main chain, the following principles should be considered in turn: priority should be given to the smaller side chain rank, priority should be given to the more carbon atoms in each side chain, and priority should be given to the fewer side branches. After the main chain is determined, the main chain should be numbered according to the principle of minimum series. The principle of minimum series is to make the number of substituents as small as possible. If there are multiple substituents, compare them one by one until they are lower than others. Finally, according to the basic format of the name of organic compounds, write the full name.

Nomenclature of monocycloparaffins

Determination of 1. R-S configuration

People's left and right hands are mirror images of each other, but they cannot overlap. This property of the hand is called chirality. When a carbon atom connects four different groups, two different three-dimensional structures can be produced, which are mirror images of each other but cannot overlap, that is, they are chiral, so the carbon atom connecting four different groups is called chiral carbon atom. In order to distinguish two different stereo structures caused by chiral carbon, the chiral carbon of one stereo structure is called R configuration, while the chiral carbon of the other stereo structure is called S configuration. It is also stipulated that the configuration of chiral carbon should be determined according to the following methods: four groups connected with chiral carbon atoms are arranged in regular order, the smallest group is placed farthest from the eyes, and the other three groups rotate clockwise in the direction from big to small, and the chiral carbon is R configuration (prefix of Latin rectus muscle); The rotation direction is counterclockwise, and the chiral carbon is S configuration (prefix of Latin sinister).

2. Determination of cis-trans configuration of cyclic compounds

Because the single bond of ring-forming carbon atoms cannot rotate freely, when there are two or more groups on the ring, two or more stereoisomers will be produced. Two substituents of one isomer are called cis configuration on the same side of the ring, and two substituents of another isomer are called trans configuration on the opposite side of the ring.

3. Naming of Monocycloalkanes

Cycloalkanes with only one ring are called monocyclic alkanes. When naming cycloalkanes with no substituent on the ring, just add a ring before the corresponding alkane.

Monocycloalkanes with substituents on the ring have two names. When the substituents on the ring are complex, the chain should be used as the mother and the ring as the substituent, and the name should be named according to the naming principles and methods of alkanes. When the substituent on a ring is simple, the ring is usually named as the parent. When there are two or more substituents on the ring, the mother ring should be numbered, and the numbering still follows the principle of minimum series.

However, because rings have no end groups, sometimes there are several numbering methods that conform to the principle of minimum series. In other words, it is impossible to determine which number takes precedence by applying the principle of minimum series. In this case, when naming in Chinese, the order of smaller groups in the order rules should be as small as possible.

When there are two or more substituents on the ring, if the molecule is anti-axisymmetric, the configuration is represented by cis-trans, the molecule is not anti-axisymmetric, and the configuration is represented by R-S.

When there are three or more groups on the ring, if cis and trans are used to represent the configuration, a reference group should be selected. Usually, the group at the position of 1 is selected as the reference group, which is represented by r- 1 and placed before the name.

Nomenclature of bridged cycloalkanes

Bridged hydrocarbons refer to polycyclic alkanes sharing two or more carbon atoms, and the shared carbon atoms are called bridgehead carbons. There can be a carbon chain or a bond between two bridgehead carbons, which is called a bridge. When the bridged hydrocarbon becomes a chain compound, the carbon chain must be broken, and the number of rings is determined according to the number of broken carbon chains. If the bridge hydrocarbon needs to be broken twice, it is called bicyclic, and if it needs to be broken three times, it is called tricyclic. , the number of carbon atoms between bridgehead carbons (excluding bridgehead carbons) is listed in square brackets from most to least, and the numbers are separated by dots in the lower right corner. Finally, write the name of alkane with the total carbon number of bridge hydrocarbon including bridgehead carbon. If there is a substituent on the bridged ring hydrocarbon, it is listed before the full name. The number of bridge ring hydrocarbons starts from the first bridgehead carbon, from the longest bridge to the second bridgehead carbon, and then returns to the first bridgehead carbon along the second longest bridge, and then the remaining bridges are numbered in descending order. If numbering can be selected, the number of substituents should be reduced as much as possible.

For some bridged hydrocarbon compounds with complex structures, the commonly used names are adamantane, cubic alkane and so on.

Nomenclature of spirocycloalkanes

Spiroalkanes refer to polycyclic alkanes that share a carbon atom between single rings, and the shared carbon atom is called spiro atom. The number of spiral rings starts from the small ring on the spiral atom and is numbered from the first ring to the second ring in turn. When naming, write the prefix snail first, and then write the number of carbon atoms in the ring except spiral atoms in square brackets in numerical order, and separate the numbers with dots. Finally, the names of alkanes containing carbon atoms, including spiral atoms, are written. If there are substituents, the number of substituents should be reduced as much as possible, and the number and name of substituents are listed in front of the full name.

Olefins and alkynes

Nomenclature of Monoolefins and Monoalkynes

The systematic naming of monoolefins can be carried out according to the following steps:

(1) First, the longest carbon chain with a double bond is found as the main chain, and the compound is named olefin according to the number of carbon atoms in the main chain. If the main chain contains four carbon atoms, it is called butene. Use Chinese characters and numbers for more than ten carbons, and add carbon characters, such as dodecene.

(2) Starting from the end of the main chain close to the double bond, the carbon atoms in the main chain are numbered in turn, so that the number of carbon atoms in the double bond becomes smaller.

(3) Write the minimum number of carbon atoms with double bonds before the name of the alkene. The number of carbon atoms in the substituent is written before the substituent, and the substituent is also written before the olefin.

(4) If two carbon atoms with double bonds in the molecule are connected to different groups, two stereoisomers will be produced, which can be represented by Z-E configuration. That is to say, according to the sequence rules, two atoms (or groups) on two double-bond carbon atoms are in Z configuration (Zusammen, meaning together) on one side of the double bond and in E configuration (Entgcgen, meaning opposite) on both sides.

(5) Write the full name according to the name format.

The systematic naming method of monoacetylene is the same as that of monoalkene, but there is no problem of determining Z-E configuration.

Systematic nomenclature of polyenes or polyenes.

The systematic naming of multiolefins is carried out according to the following steps.

(1) takes the longest carbon chain with the most double bonds as the main chain, which is called rare, and is the mother name of this compound. The number of carbon atoms in the main chain starts from the end near the double bond, and the position of the double bond is arranged from small to large, written in front of the mother name and connected by short lines.

(2) The position of the substituent is determined by the arrangement order of carbon atoms in the main chain connected with it, which is written before the name of the substituent and connected with the name of the substituent with a short line.

(3) When writing a name, the substituent comes first and the parent comes last. If it is cis or trans isomer, the Z-E configuration of double bond should be indicated in front of the full name.

The systematic naming method of polyacetylene is the same as that of polyene.

Systematic nomenclature of alkynes

If the molecule contains both double bonds and triple bonds, alkynes can be used as suffixes, and the numbers of double bonds and triple bonds should be as low as possible. If the label number is selected, the label number of the double bond should be smaller than that of the triple bond, and the alkene should be followed by the alkyne when writing.

aromatic hydrocarbon

Nomenclature of Monocyclic Aromatic Hydrocarbons Containing Phenyl

The simplest monocyclic aromatic hydrocarbon of this kind is benzene. Other monocyclic aromatic hydrocarbons can be considered as substitutes for mono-or polyalkyl groups of benzene. There is only one monoalkyl substituent of benzene. There are two methods of naming, one is based on benzene. As a substituent, the hydrocarbyl group is called XX benzene. The other is to use benzene as a substituent, called phenyl, which is the group left after benzene molecule subtracts a hydrogen atom. It can be abbreviated as pH-, and the part outside the benzene ring is used as the parent, which is called phenyl (free radical) XX.

There are three isomers of binary hydrocarbyl substituents of benzene, which are caused by the different relative positions of substituents on benzene ring. When naming, o or o (o) indicates that two substituents are in the ortho position, m (m) indicates that two substituents are on two carbons separated by a carbon atom, and p (p) indicates that two substituents are in the diagonal position. O, m and p can also be used as 65438.

If there are three identical substituents on the benzene ring, "Lian" (abbreviated as "vie" in English) is often used as the prefix, indicating that the three groups are at 1, 2 and 3 respectively. Prefixed with "piece", it means that three groups are at 1, 2, 4 positions. Prefixed with "Jun", it means that the three groups are in 1, 3 and 5 positions.

When there are two or more substituents on the benzene ring, the numbering on the benzene ring should conform to the principle of minimum series. However, when the principle of minimum series cannot be used to determine which number takes precedence, as in the case of single cyclic chain, Chinese naming should make the smaller group in sequence rules as small as possible.

Nomenclature of polycyclic aromatic hydrocarbons

Hydrocarbons containing multiple benzene rings in the molecule are called polycyclic aromatic hydrocarbons. There are mainly polyphenylaliphatic hydrocarbons, biphenyls and condensed polycyclic aromatic hydrocarbons.

1. Naming of polyphenylated aliphatic hydrocarbons

Compounds in which hydrogen in chain hydrocarbon molecules is substituted by two or more phenyl groups are called polybenzylated aliphatic hydrocarbons. When naming, phenyl is generally used as substituent and chain hydrocarbon is used as parent.

2. Naming of biphenyl compounds

Compounds in which two or more benzene rings are directly connected by a single bond are called biphenyl compounds.

The numbering of biphenyl compounds always starts with the direct connection between benzene ring and single bond, with one apostrophe added to the number on the second benzene ring, two apostrophes added to the number on the third benzene ring, and so on. If there are substituents on the benzene ring, the direction of numbering should be as small as possible, and biphenyl should be used as the parent when naming.

3. Naming of polycyclic aromatic hydrocarbons

Compounds in which two or more benzene rings share two ortho-carbon atoms are called polycyclic aromatic hydrocarbons. The simplest and most important polycyclic aromatic hydrocarbons are naphthalene, anthracene and phenanthrene.

The quantities of naphthalene, anthracene and phenanthrene are all fixed.

The 1, 4, 5 and 8 positions of naphthalene molecule are equivalent positions, which are called α positions, and the 2, 3, 6 and 7 positions are also equivalent positions, which are called β positions. The 1, 4, 5 and 8 positions of anthracene molecules are equivalent, also called α position, 2, 3, 6 and 7 positions are also called β position, and 9, 10 positions are equivalent, also called 7 positions. There are five pairs of equivalent positions in the Philippines, namely: 1, 8, 2, 7, 3, 6, 4, 5, 9, 10. The name format of substituted polycyclic aromatic hydrocarbons is consistent with the basic format of organic compound names.

IUPAC has 35 kinds of internationally used condensed ring hydrocarbons, which can be used as the naming parent. Their structures, English names and numbers are shown in the Atlas.

Non-benzene aromatic hydrocarbon

Common monocyclic non-benzene aromatic compounds can be named according to the general principles mentioned above. Aminene is a cyclic hydrocarbon with alternating single and double bonds. When naming, put the number of carbon atoms in the ring in square brackets, and write rotaene after the brackets. You can also connect the number with the rotor with a short line instead of writing brackets. For example, the fourth compound mentioned above can be called [18] annulene or 18- annulene. Moonene can also be named according to the number of hydrocarbons. 18- annulene contains eighteen carbons and nine double bonds, so it can also be called cyclic octadecene.

Hydrocarbon derivative

Compounds in which hydrogen in hydrocarbon molecules is replaced by functional groups are called hydrocarbon derivatives.

Prefix and suffix names of common functional groups, suffix name group suffix name -COOH carboxylic acid -SO3H sulfonic acid -COOR ester -COX haloformyl halide -CONH2 carbamoyl amide-anhydride -CN cyanonitrile -CHO formaldehyde carbonyl ketone -OH hydroxy alcohol -OH hydroxy phenol system nomenclature -NH2 amino amine-or alkoxy ether -R atom -NO2 nitro -NO nitroso-monofunctional compound.

Compounds containing only one functional group are called monofunctional compounds. There are two cases of systematic naming of monofunctional compounds. One case is that functional groups are used as substituents and alkanes are still used as the matrix, so they are named according to the naming principle of alkanes.

If the functional group is an ether bond, it can also be named as follows: take a longer hydrocarbon group as the matrix, use the remaining alkoxy group (RO-) with less carbon atoms as the substituent, and if there is an unsaturated hydrocarbon group, choose a hydrocarbon group with greater unsaturation as the matrix.

In another case, the longest chain containing functional groups is the main chain of the parent compound, which is called A(A= alcohol, aldehyde, ketone, acid, acid halide, amide, nitrile, etc. ) according to the number of carbon atoms in the main chain. Starting from the end near the functional group, the carbon atoms in the main chain are numbered in turn. When writing a full name, write the number of the carbon atom where the functional group is located before a number, and draw a short line between a and the number. The position and name of the branch chain are written in front of a number and separated by short lines.

When a ring is connected to a chain with terminal functional groups, and there are no heteroatoms and heavy bonds in this chain, the connection naming method can be used in IUPAC system naming, that is, the names of the two can be connected to form the name of this compound.

Anhydride can be regarded as the product of two molecules of carboxylic acid losing one molecule of water. The two molecules of carboxylic acid are the same and are mono-anhydrides. When naming, add the word "anhydride" after the name of carboxylic acid, and remove the word "acid" of carboxylic acid. If two carboxylic acid molecules are different, they are mixed anhydrides. When naming, put the simple acid at the front and the complex acid at the back, then add the word "anhydride" and remove the word "acid"; Diatomic acids lose water in their molecules to form cyclic anhydrides. When naming dibasic acids, add the word "anhydride" after their names.

Ester can be regarded as the product that carboxyl hydrogen atom of carboxylic acid is replaced by alkyl group. When naming, put the name of carboxylic acid before, the name of alkyl group after, and add the word "ester". The hydroxyl group and carboxyl group in the molecule lose water to form lactone. Replace the word "acid" with the word "lactone" and indicate the position of hydroxyl group.

Systematic nomenclature of compounds containing multiple identical functional groups

When the molecule contains two or more identical functional groups, the long chain with the largest number of functional groups should be named as the main chain, and then called N alcohol (or N aldehyde, N ketone, N acid, etc. ) According to the number of carbon atoms in the main chain, where n is the number of functional groups in the main chain, expressed by chinese numerals. For example, a diol with seven carbon chains is called heptanediol.

If carboxyl groups are directly attached to aliphatic and aromatic rings, or there are more than three carboxyl groups in a carbon chain, carboxylic acids, dicarboxylic acids and tricarboxylic acids can also be added directly after the name of the hydrocarbon.

When a molecule contains multiple functional groups, a main functional group must be determined first. The way to determine the main functional group is to look at the table "Prefix and Suffix Names of Common Functional Groups" above. The functional group ranked first in the table is always the main functional group. Then, the longest carbon chain with main functional groups and as many functional groups as possible is selected as the main chain. The principle of main chain numbering is to make the order of main functional groups as small as possible. When naming, the name of the matrix is determined according to the main functional groups, and other functional groups are represented by prefixes as substituents. If the molecule involves three-dimensional structure, its configuration should be indicated in front of the name. Then write the name in its basic format. IUPAC nomenclature is a systematic method for naming organic compounds. This nomenclature is stipulated by the International Union of Pure and Applied Chemistry (IUPAC). Its predecessor is 1892 "systematic nomenclature" of Geneva Internationalization Society. Ideally, every organic compound with a clear structural formula can be described by a clear name. In fact, it is not a strict systematic nomenclature, because it also accepts the usual general nomenclature of some substances and groups. The systematic nomenclature of Chinese was formulated by chinese chemical society on the basis of the English IUPAC nomenclature and combined with the characteristics of Chinese characters. 1960, 1980 revised according to English version 1979.

IUPAC organic nomenclature is a systematic method for naming organic compounds. This nomenclature is stipulated by IUPAC, and was last revised in 1993. Its predecessor is 1892 "systematic nomenclature" of Geneva Internationalization Society. Ideally, every organic compound with a clear structural formula can be described by a clear name.

General rule

Ordering rules of substituents

When there are many substituents in the main chain, the order of groups in the name is determined by the ordering rule. The general rule is: comparing the atomic number of the first atom of each branch chain and substituent connected to the carbon atom of the main chain (isotope by relative atomic weight), the group with larger atomic number is the "better" group. The higher the ordinal number, the higher the order. Note: Generally speaking, the greater the ordinal number, the greater the relative atomic mass. So we can also compare the relative atomic masses. For example: I & gtBr & gtCl & gtF>O>N>c. If the first atoms are the same, compare the order of the atoms connected to their first atoms; If there is a double bond or triple bond, it is considered that two or three identical atoms are connected. The functional group with the highest ranking is the main functional group, which is named as the last one. For other functional groups, the lower the naming order, the higher the name.

Example:-ch2br > -CH3

The first atoms of these two groups are the same (both are C atoms), so the atoms connecting C atoms are Br, H, H (in descending order of atomic number) and H, H, H, because Br >；; h，so-CH2Br & gt； -CH3 .

Selection of main chain or main ring system

The longest carbon chain containing the main functional group is taken as the main chain, and the end near the functional group is marked as carbon 1.

If the core of a compound is a ring (system), then this ring system is regarded as the parent; Except benzene ring, each ring system determines the carbon number 1 according to its own rules, but at the same time, it must ensure that the number of substituent positions is the minimum.

A carbon atom connected to the main chain in the branch chain is labeled as carbon 1.

figure

The position number is represented by Arabic numerals.

The number of functional groups is represented by Chinese characters and numbers.

The number of carbon atoms in the carbon chain within 10 is represented by heavenly stems, and the number outside 10 is represented by Chinese characters and numbers.

Iupac organic chemistry terminology