"Tiangong Kaiwu" says: "The use of this product is related to people's livelihood." However, the "2,3-diene-1-alkyne-4-methylnaphthalene" mentioned in the ancient "Tiangong Kaiwu" has not been described. In today's knowledge, this compound has a wide range of uses.
In the field of organic synthesis, it can be used as a key intermediate. Due to the unique unsaturated bond layout in the molecule, it can be used for a variety of organic reactions, such as nucleophilic addition, cyclization reaction, etc., which can be cleverly designed and transformed into complex organic molecules. This is of great significance in the creation of new drugs, functional materials and other fields. Taking drug synthesis as an example, molecular frameworks with specific biological activities can be constructed according to their structural characteristics, paving the way for the development of specific new drugs.
In the field of materials science, with its conjugated structure and special electronic properties, it may be used to prepare materials with special photoelectric properties. For example, organic Light Emitting Diode (OLED) materials, with their structural modulation, may be able to optimize luminous efficiency and color purity, improve the quality of display technology; in the field of solar cell materials, it may enhance the ability to capture light and charge transport, improve photoelectric conversion efficiency, and contribute to the development of renewable energy.
Although it is difficult for Tiangong Kaiwu to provide details of the uses of this microscopic molecule, today's science and technology are flourishing, and such compounds play a key role in many cutting-edge fields, promoting the continuous progress of human civilization and benefiting the common people.

"Tiangong Kaiwu" said: "Alkanes are gathered in one." Methane is the simplest alkane and has unique physical properties.
First of all, its physical state, under room temperature and pressure, methane is gaseous. Because of the weak force between methane molecules, it is difficult to bind the free movement of molecules, so it mostly exists in the gas phase, colorless and formless, and can only be detected by instruments.
The density of methane is lower than that of air. According to common sense, under the same temperature and pressure, the density of gas is related to molecular weight. The molecular weight of methane is only 16, which is much lower than the average molecular weight of air about 29. It is lighter than air and can float on it.
Furthermore, in terms of its solubility, methane is extremely difficult to dissolve in water. Methane molecules are non-polar molecules, while water molecules are polar molecules. According to the principle of "similarity and dissolution", the polarities of the two are different, and the interaction is weak, causing methane to be insoluble in water and more to escape into bubbles in water.
has a boiling point and a melting point. The boiling point of methane is -161.5 ° C and the melting point is -182.5 ° C, both of which are very low. This is due to the fact that there is only a weak van der Waals force between molecules. With a little energy, the molecules can break free and change from solid to liquid and then to gas, and condense into liquid or solid in a low temperature environment.
In addition, methane is odorless, and it is difficult for ordinary people to smell its taste. However, in natural gas, odorous substances are often added in order to detect leaks. Because natural gas contains methane, it is difficult to detect the leakage of colorless and odorless methane. After adding the odor agent, once it leaks, people can quickly know by smell and prevent problems before they occur.
In summary, methane is gaseous at room temperature and pressure, has a density lower than that of air, is extremely difficult to dissolve in water, has a very low melting point and is odorless. All these physical properties are of great significance for its exploitation, storage, transportation and application. It is used by the world and should be understood in order to avoid its risks.

Alas! If you want to know the chemical properties of methylaminopyridine, please listen to me in detail.
Methylaminopyridine is also a nitrogen-containing organic compound. Its molecular structure is unique, and the nitrogen atom is in it, giving it a different chemical activity.
As far as acidity and alkalinity are concerned, methylaminopyridine is weakly basic because the nitrogen atom has a lone pair of electrons. Under appropriate conditions, it can react with acids to form salts. This property makes it a base catalyst in many organic synthesis reactions, helping the reaction to proceed smoothly.
Its nucleophilicity is also worth mentioning. The lone pair electrons on the nitrogen atom make methylaminopyridine nucleophilic and can undergo nucleophilic substitution reactions with electrophilic reagents. In the field of organic synthesis, this property is often used to form new carbon-nitrogen bonds or other chemical bonds, which contribute to the creation of complex organic molecules.
Furthermore, the substituent effect of methylaminopyridine cannot be ignored. The presence of methylamino groups has an impact on the distribution of electron clouds in the pyridine ring, changing its reactivity and selectivity. In the aromatic electrophilic substitution reaction, methylamino groups are the power supply groups, which can increase the density of electron clouds in the adjacent and para-positions of pyridine ring, making it easier for electrophilic reagents to attack these two positions, thus dominating the reaction direction.
In addition, methylaminopyridine can participate in many redox reactions. Under the action of specific oxidants or reducing agents, its pyridine ring or methylamino group can undergo corresponding oxidation or reduction transformation, deriving a variety of chemical products, expanding a broad path for organic synthesis.
In short, methylaminopyridine is rich in chemical properties and has important uses in many fields such as organic synthesis and medicinal chemistry. It is also a key compound in chemical research and application.

"Tiangong Kaiwu" is a scientific and technological masterpiece written by Song Yingxing in the Ming Dynasty, and it contains many technological techniques. As for the compound "2,3-diol-1-ether-4-methylphenol", although the book does not directly correspond to the preparation method of modern chemistry, it can be prepared according to the relevant process ideas of the ancients, and traditional raw materials and techniques can be used to deduce its possible preparation methods.
In ancient times, there were many experiences in the preparation of similar organic compounds. Such as distillation, fermentation, extraction, etc. As for "2,3-diol-1-ether-4-methylphenol", plant raw materials rich in phenols and alcohols can be found. In ancient times, plant extracts were widely used, such as obtaining special ingredients from certain trees and herbs.
You can first find plants containing phenolic substances, such as some coniferous plants such as pine and cypress, whose resins or phenolic components. After crushing such plant raw materials, soak them in water or organic solvents such as rice wine, vinegar, etc. This is a common extraction method in ancient times. After soaking, the mixed liquid is obtained, and then separated and purified by distillation. Distillation was also a mature technology in ancient times. By controlling the temperature, the different boiling point components in the mixed liquid are gasified and condensed successively. Distillates containing phenolic components or precursors containing target compounds.
For the alcohol part, it can be prepared by fermentation method. The ancients made good use of grains and fruits to ferment to obtain alcohols such as ethanol. Or the fermentation product can be reacted with the above-mentioned phenol-containing fraction. Although modern precise reaction conditions were not controlled in ancient times, it may be possible to promote its binding by gentle reaction for a long time. For example, the phenol-containing fraction and the alcohol obtained by fermentation are placed in a closed container and left to stand at room temperature or slightly hot environment. During this period, some natural catalysts may need to be added, such as some plant ash, which may contain metal ions, etc. The catalytic reaction can be carried out. After a long time of reaction, it can be distilled and separated for many times, or "2,3-diol-1-ether-4-methylphenol" or its like can be obtained. Although it is difficult to achieve the purity and yield of modern chemistry, according to the idea of "Tiangongkai", traditional raw materials and operations can be used to explore their preparation methods.

Acetyl is used in storage and storage, just as "Tiangong" said, there is a need to pay attention to it.
Acetyl is easy to degrade, which is the first thing to pay attention to. Its chemical activity is easy to start and degrade when it encounters common materials. If the storage environment is not properly controlled, such as the degree and temperature of acetyl are not suitable, and the quality of acetyl is affected. If the degree is high, the molecules will be strong, accelerating the degradation and reaction; if the degree is too large, the water vapor will melt, which will also promote its degradation. Therefore, it is appropriate to keep it dry and cool to maintain its activity.
Furthermore, light also affects acetyl. Light contains energy, which can lead to photochemical reaction. If the acetyl chloride is exposed to light, the molecule may be damaged or destroyed, resulting in a decrease in activity. It can be stored in an opaque container or hidden in the dark.
In addition, the interaction of the acetyl container cannot be ignored. Some materials or their reaction, adsorb acetyl, resulting in a small content. Such as some gold materials, or lead to chemical reactions, change the chemical properties of acetyl. Containers of inert materials, such as specific plastics or glass materials, should be used. The reaction of acetyl is minimal and can be properly stored.
On the way, vibration also takes into account factors. Modify the action of strong vibration or acetyl-causing molecules, affecting their activity. Therefore, it is necessary to take shock-proof measures, such as wrapping with materials, to reduce vibration.
In this regard, acetyl should be used for storage and maintenance, and the factors of caution, accuracy, lighting, equipment and vibration should be used to ensure its activity. As advocated in "Tiangong Wuwu", it is only possible to worry about governance.