5,6,7,8-TETRAHYDROQUINOLINE

Tetracyanoethylene, that is, 5, 6, 7, 8-tetracyano-5, 6, 7, 8-tetrahydroacenaphene, its main use is not explicitly mentioned in "Tiangong Kaiwu", but it can be explored with current scientific knowledge.
Tetracyanoethylene has strong electron absorption. In the field of organic synthesis, it is often used as a diene-friendly body to participate in the Diels-Alder reaction. This reaction is an important means of building carbon-carbon bonds. It can synthesize complex organic compounds or lay the foundation for the preparation of special functional materials and pharmaceutical intermediates.
In materials science, it can form charge transfer complexes with electron donors. This complex exhibits unique electrical and optical properties, or can be used to fabricate new conductive materials and optoelectronic devices. For example, some charge transfer composites have semiconductor properties. In the field of organic electronics, it is expected to become a key material for the production of organic field-effect transistors and organic Light Emitting Diodes, so as to realize the flexibility and lightweight of electronic devices and open up new forms of electronic devices.
In supramolecular chemistry, tetracyanoethylene can interact with other molecules through non-covalent interactions, such as π-π stacking, hydrogen bonding, etc., to form supramolecular systems. These supramolecular systems have potential applications in molecular recognition, self-assembly, etc., or can design host molecules with high selective recognition ability for specific molecules, which can be used in chemical sensors to accurately detect specific substances in the environment.
In summary, although tetracyanoethylene is not found in "Tiangong Kaiwu", from today's perspective, it has important uses in organic synthesis, materials science, supramolecular chemistry and other fields, and is of great significance to promote the development of modern science and technology.

The physical properties of tetracyanoethylene are as follows:
tetracyanoethylene is a yellow crystal at room temperature and has a slight odor. The melting point is relatively high, about 197-198 ° C. This characteristic is due to the strong interaction between molecules, such as the formation of hydrogen bonds and π-π stacking between cyanos, which makes the crystal structure stable and requires a higher temperature to destroy the lattice.
Its boiling point is about 223-224 ° C. The higher boiling point is also due to the strong intermolecular force, which requires more energy to overcome the force to make the molecules escape from the liquid phase.
The density of tetracyanoethylene is about 1.28g/cm ³, and the density is related to the molecular weight and the degree of molecular packing. Its molecule contains multiple heavy atoms and has a relatively compact structure, resulting in a density in this range.
It is insoluble in water because its molecules are non-polar, and water is a polar solvent. According to the principle of "similar miscibility", the two are insoluble. However, tetracyanoethylene is soluble in some organic solvents, such as dichloromethane, chloroform, tetrahydrofuran, etc. These organic solvents and tetracyanoethylene molecules can interact with each other through van der Waals forces to achieve dissolution.
In addition, tetracyanoethylene has certain sublimation properties, and under appropriate conditions, it can directly transform from a solid state to a gaseous state. This property is related to the intermolecular force and crystal structure. The relatively weak intermolecular force makes it easy for some molecules to obtain enough energy to break away from the crystal surface and directly vaporize.

Carbon tetrachloride, a colorless and transparent liquid, has a special odor. Its chemical properties are stable, and under normal conditions, it is not easy to react with water, acids and bases.
Carbon tetrachloride molecules have a tetrahedral structure, with carbon atoms in the center and four chlorine atoms at the apex of the tetrahedron. Because the polarity of carbon-chlorine bonds cancels each other, carbon tetrachloride is a non-polar molecule.
Chemical stability results from the high carbon-chlorine bond energy. Under heating conditions, carbon tetrachloride will react with certain metals. In case of hot metal potassium, it will react violently to form potassium chloride and potassium carbide.
Carbon tetrachloride will also slowly hydrolyze, but its degree of hydrolysis is extremely weak. Because water is a polar molecule and carbon tetrachloride is non-polar, the two are In a strong alkali solution or at high temperatures, the hydrolysis rate will accelerate.
Under light, carbon tetrachloride can undergo photochemical reactions. For example, under ultraviolet radiation, carbon tetrachloride can decompose to produce chlorine and trichloromethane radicals. This reaction is a chain reaction. Once initiated, it will continue to produce a variety of chlorine-containing organic compounds and chlorine gas.
Carbon tetrachloride does not burn and can be used as a fire extinguishing agent. Because of its stable chemical properties, low boiling point, and volatile, it can quickly cover the source of fire and isolate oxygen for the purpose of extinguishing fire. However, due to its destructive effect on the ozone layer, it has been used less today.
Carbon tetrachloride is a good organic solvent and can dissolve a variety of organic compounds. Such as soluble oils, resins, rubber, etc. This is due to its non-polar molecular structure, which follows the principle of "similar miscibility" and attracts each other with non-polar or weakly polar organic matter to achieve dissolution.

"Tiangong Kaiwu" says: "The silk, hemp, fur and brown in the world are all of quality, and the special face and color are still there. It is said that those who do not work hard to create things, I do not believe it." This is the beauty of dyeing. The synthesis method of 5% 2C6% 2C7% 2C8 -tetraamino square light (suspected to be "tetraamino square acid" error) is also related to the art of chemical creation. It should be viewed with the wisdom of the ancients.
To make 5% 2C6% 2C7% 2C8 -tetraamino square acid, one method can be selected from the raw material. Based on suitable organic compounds, such as those containing specific functional groups, through a delicate reaction process, it may be caused to form. "Tiangong Kaiwu" says: "Water and fire are both good and soil is harmonious." Just like chemical synthesis, when raw materials meet, water and fire (reaction conditions) are adjusted, and a harmonious change can be achieved. Compounds containing amino groups and those with corresponding active groups can react with each other under suitable temperature, pressure and catalyst.
Temperature control is crucial. The ancient people made alchemy, and the heat should not be poor. If it is too high, the reaction will be too fast, and the product will be impure; if it is too low, the reaction will be slow and time-consuming. "Tiangong Kaiwu" The art of casting is also heavy heat, and this is the same. Therefore, when synthesizing, it is necessary to use a precise device to measure the temperature, so that the reaction can be carried out in the best range.
The setting of pressure cannot be ignored. Appropriate pressure can make the collision between molecules more effective and promote the progress of the reaction. For example, the ancients used water power and wind power to help them work hard to achieve twice the result with half the effort. When synthesizing 5% 2C6% 2C7% 2C8-tetraaminoglyclic acid, the appropriate pressure can be found according to the reaction characteristics, or the pressure value can be adjusted by means of a closed device.
The choice of catalyst is like a good work selector. It can change the rate of chemical reactions without being consumed. A good catalyst can make the reaction go smoothly like a boat. It can be selected from a variety of compounds to evaluate their catalytic efficiency for the reaction, and the reaction path can be optimized to improve the yield and purity of 5% 2C6% 2C7% 2C8-tetraaminoglyclic acid.
In addition, the reaction environment, such as the choice of solvent, is also very particular. In "Tiangong Kaiqi", sugar is boiled in water, and water is the solvent. When synthesizing this substance, choose a suitable solvent, which can fully dissolve the reactants and mix them evenly, which is conducive to the progress of the reaction. When choosing a polar or non-polar solvent according to the properties of the reactants and products, the synthesis process is smoother.

Five, six, seven, and eight of the four square lights are the most important utensils, and the use of them is like paying attention, and do not neglect them.
First, check the surface before using it. If it is outside, there is a problem of breaking or cracking. If there is such a thing, it must be used for its use, or it may cause danger. For example, if there is a slight crack in the wall of the utensil, it will be made, and the force of the parts may cause it to crack, and it will be damaged by people and things, and it will not turn the heel.
Second, place the utensil, and it will be flat and solid. If the utensil is not made, it may be shaken. If it is not placed properly, it will fall, and it will not be damaged, and it will also endanger the people around it. And it is appropriate to open the surroundings, and block the objects, so that the operation can be scattered.
Third, the operation must be carried out according to the order. Be familiar with the method of operation and do not act rashly. Every step is reasonable, and it is easy to cause accidents. Such as the order of the passage and the method of the order of the order, all follow.
Fourth, use the oil to properly manage. Clean the surface, remove the stain and dirt. If there are parts grinding, and even more. Store the oil, it should be dry and clear, to avoid moisture and rot, so that it can be extended, and ensure that it can often be used.
In this way, the use of four square lights is important, and it is necessary to pay attention to things like this, in order to be safe and effective.