MindMap Gallery Organic chemistry knowledge collection
Organic chemistry, also known as the chemistry of carbon compounds, is the science that studies the composition, structure, properties, preparation methods and applications of organic compounds. It is an extremely important branch of chemistry. This picture describes the contents of isomers, homologues, naming of organic compounds, common methods for separating and purifying organic substances, methods for determining the molecular formula of organic substances, and identification of molecular structures.
Edited at 2020-02-25 08:20:44One Hundred Years of Solitude is the masterpiece of Gabriel Garcia Marquez. Reading this book begins with making sense of the characters' relationships, which are centered on the Buendía family and tells the story of the family's prosperity and decline, internal relationships and political struggles, self-mixing and rebirth over the course of a hundred years.
One Hundred Years of Solitude is the masterpiece of Gabriel Garcia Marquez. Reading this book begins with making sense of the characters' relationships, which are centered on the Buendía family and tells the story of the family's prosperity and decline, internal relationships and political struggles, self-mixing and rebirth over the course of a hundred years.
Project management is the process of applying specialized knowledge, skills, tools, and methods to project activities so that the project can achieve or exceed the set needs and expectations within the constraints of limited resources. This diagram provides a comprehensive overview of the 8 components of the project management process and can be used as a generic template for direct application.
One Hundred Years of Solitude is the masterpiece of Gabriel Garcia Marquez. Reading this book begins with making sense of the characters' relationships, which are centered on the Buendía family and tells the story of the family's prosperity and decline, internal relationships and political struggles, self-mixing and rebirth over the course of a hundred years.
One Hundred Years of Solitude is the masterpiece of Gabriel Garcia Marquez. Reading this book begins with making sense of the characters' relationships, which are centered on the Buendía family and tells the story of the family's prosperity and decline, internal relationships and political struggles, self-mixing and rebirth over the course of a hundred years.
Project management is the process of applying specialized knowledge, skills, tools, and methods to project activities so that the project can achieve or exceed the set needs and expectations within the constraints of limited resources. This diagram provides a comprehensive overview of the 8 components of the project management process and can be used as a generic template for direct application.
organic chemistry
Isomers
Writing rules
1. Alkanes: Alkanes only have carbon chain isomerism. When writing, be sure to be comprehensive and not repetitive. The specific steps are as follows: Form a straight chain - first connect all the carbon atoms into a straight chain Pick a carbon and hang it in the middle - remove a carbon atom from the main chain as a branch chain and connect it to the middle carbon of the remaining main chain Move to the edge without reaching the end - try to connect the methyl groups to the carbon atoms of the main chain from the inside out, but do not place them on the end carbon atoms. Pick multiple carbon atoms into pieces - pick different numbers of carbon atoms from least to most to form branch chains of different lengths Multi-branched chains between the same neighbor - When there are multiple identical or different branch chains, they should be tried in order of the same carbon atom, adjacent carbon atoms, and interphase carbon atoms.
Organic compounds with the same functional groups
Generally written in the order from carbon chain isomerism to positional isomerism to functional group isomerism
Aromatic compounds: There are three positions of the two substituents on the benzene ring: ortho, meta, and para.
How to determine the number of isomers
(1) Memory method: Remember the number of isomers of some common organic compounds, such as a: Any molecule containing only one carbon atom has no isomers; b: There are no isomers in ethane, propane, ethylene and acetylene; c: Alkanes with 4 carbon atoms have 2 isomers, alkanes with 5 carbon atoms have 3 isomers, and alkanes with 6 carbon atoms have 5 isomers.
(2) Elementary element method: If there are 4 kinds of butyl groups, then there are 4 kinds of isomers of butanol, valeraldehyde and valeric acid.
(3) Substitution method: For example, dichlorobenzene (C6H4CL2) has 3 isomers, and tetrachlorobenzene also has 3 isomers (exchange H and CL); another example is that the monochloride of methane has only 1 species; there is only 1 monochloride of neopentane.
(4) Equivalent hydrogen method: The equivalent hydrogen method is an important method to determine the number of isomers. Its rules are: a: Hydrogen atoms on the same carbon atom are equivalent. b: Hydrogen atoms on methyl groups with the same number of carbon atoms are equivalent c: The hydrogen atom on the carbon atom at the symmetrical position is equivalent
Homologues
A class of homologues of chemical substances that are basically similar, but whose physical properties change as the number of carbon atoms increases.
The greater the relative molecular mass, the greater the melting and boiling point
Judgment rules
Features
Homologues must be the same substance
Homologues differ by n CH2
The chemical formulas of homologues must not be the same
Homologues must have the same constituent elements
Homologues have similar structures
Nomenclature of organic compounds
(1) Customary nomenclature of alkanes Number of carbon atoms: When they are the same, use "normal", "different" and "new" to distinguish; More than ten, represented by Chinese numerals; Ten and below are represented by A, B, C, D, Wu, Ji, Geng, Xin, Ren, and Kui.
Systematic nomenclature of alkanes: Choose the main chain - choose the longest carbon chain as the main chain Numbering position - starting from the end closest to the branch chain Write the name - first simplify and then complex, merge with the same base
(3) Naming of alkenes and alkynes: Select the main chain - take the longest chain containing a carbon-carbon double bond or a carbon-carbon triple bond as the main chain, which is called "a certain alkene" or "a certain alkyne" Numbering position - number the carbon atoms on the main chain starting from the end closest to the carbon-carbon double bond or carbon-carbon triple bond. Write the name - use the branched chain as a substituent, write it in front of "a certain alkene" or "a certain alkyne", and use Arabic numerals to indicate the position of the carbon-carbon double bond or carbon-carbon triple bond.
Nomenclature of homologues of benzene: Benzene serves as the parent, and other groups serve as substituents. The binary substituents on the benzene ring are represented by ortho, meta and pair respectively.
Commonly used methods to separate and purify organic matter
(1) Distillation Applicable objects: often used to separate and purify liquid organic matter Requirements: a: The organic matter has relatively strong thermal stability b: The difference between the boiling point of the organic compound and the magazine (2) Recrystallization Applicable objects: Commonly used to separate and purify solid organic matter Requirements: a: The solubility of the magazine in the selected solvent is very small or very large b: The solubility of the purified organic matter in this solvent is greatly affected by temperature.
(2) Extraction and separation
a: Commonly used extraction agents: benzene, carbon tetrachloride, diethyl ether, petroleum ether, dichloromethane, etc.; b: Liquid - liquid extraction agent: the process of transferring organic matter from one solvent to another by taking advantage of the different solubilities of organic matter in two mutually immiscible solvents; c: Solid - liquid extraction agent: the process of using organic solvents to dissolve organic matter from solid substances.
How to determine the molecular formula of organic matter
Elemental analysis
Quantitative analysis
After burning a certain amount of organic matter, it is decomposed into simple inorganic matter, and the amount of each product is measured, so as to calculate the simplest integer ratio of the element atoms contained in the organic matter molecule.
experimental method
a: Liebig oxidation product absorption method Organic substances containing only C, H, and O elements - H2O (absorbed with calcium chloride) CO2 (absorbed with concentrated sodium hydroxide solution) Calculate the content of carbon and hydrogen atoms in the molecule The remainder is the content of O b: Modern elemental quantitative analysis method c: Organic substances with the same relative molecular mass 1: Isomers have the same relative molecular mass. 2: The relative molecular mass of a monohydric alcohol containing n carbon atoms is the same as that of the same type of carboxylic acid and ester containing (n-1) carbon atoms. 3: The relative molecular mass of an alkane containing n carbon atoms is the same as that of a saturated monoaldehyde containing (n-1) carbon atoms.
Qualitative analysis
Use chemical methods to identify the elemental composition of organic molecules, such as C to CO2, H to H2O after combustion
Identification of molecular structure
chemical method
The functional group is identified using characteristic reactions and further confirmed by preparing its derivatives.
physical method
IR Chemical bonds or functional groups in molecules can vibrate infrared absorption. Different chemical bond functional groups have different absorption frequencies and will be in different positions on the infrared spectrum, so that information about the chemical bonds or functional groups contained in the molecule can be obtained.
H NMR Hydrogen atoms in different chemical environments - number of species: equal to the number of absorption peaks. The number of each type: proportional to the area of the absorption peak
Determination of the degree of unsaturation in organic molecules The relationship between unsaturation and structure: a: Unsaturation equal to 1, containing 1 double bond or 1 ring b: Unsaturation equal to 2, 1 triple bond or two double bonds (or one double bond and one ring) c: The degree of unsaturation is equal to 3, containing 3 double bonds or 1 double bond and 1 triple bond (or a benzene ring and two double bonds, etc.) d: The degree of unsaturation is greater than 4, and it may contain benzene rings.