Disodium 8-(Phenylamino)-5-[(E)-{4-[(E)-(5-Sulfonatonaphthalen-1-Yl)Diazenyl]Naphthalen-1-Yl}Diazenyl]Naphthalene-1-Sulfonate

This substance is called 8- (phenylamino) -5- [ (E) - {4- [ (E) - (5-sulfonaphthalene-1-yl) azo] naphthalene-1-yl} azo] naphthalene-1-sulfonate disodium salt. Its main application field is in the context of "Tiangong Kaiwu", and it can be used in dyeing and other fields.
According to "Tiangong Kaiwu", dyeing is related to the food and clothing of people's livelihood. This disodium salt has a unique structure, which can be used in dyeing workshops or as a dye. The azo structure in its molecules gives the basis for color presentation and can make the fabric look bright. In the past, dyers studied all kinds of dyes in order to obtain the brilliance and fastness of the color. This substance may be a good agent explored at that time, and can be used to color silk, cotton and other fabrics, enriching the color of people's clothing.
And it may also have its uses in paper dyeing and other aspects. In ancient times, papermaking wanted paper to be rich in color for calligraphy and painting, packaging, etc. This disodium salt may add color to the paper and make it meet different needs. For example, paper that draws exquisite pictures and packs precious objects can be colored with this dye, which is more elegant.

This is a substance called 8- (phenylamino) -5- [ (E) - {4- [ (E) - (5-sulfonaphthalene-1-yl) diazo] naphthalene-1-yl} diazo] naphthalene-1-sulfonate disodium salt. Its physical properties are as follows:
This substance is usually in solid form, and its appearance may be powdered or crystalline, depending on the preparation and purification process. The powders are fine in texture, and the crystalline ones have regular geometric shapes.
In terms of color, it often shows a specific color. Due to the presence of diazo groups and naphthalene rings in the molecular structure, it is mostly brighter, or orange, red and other colors. The specific color is related to the location, quantity and electron cloud distribution of the substituents in the molecular structure.
In terms of solubility, because it contains sulfonic acid groups, it has a certain hydrophilicity and has a certain solubility in water, which can form a uniform solution. However, the solubility is affected by factors such as temperature and pH value. Generally, when the temperature increases, the solubility increases; under a specific pH environment, the degree of ionization changes, and the solubility also changes. In organic solvents, the solubility is relatively limited. Due to the difference between molecular polarity and organic solvent polarity, it is difficult to dissolve in non-polar or weakly polar organic solvents, and has certain solubility in some polar organic solvents such as methanol and ethanol.
In terms of stability, the substance is sensitive to light and heat. Under light, groups such as diazo groups in the molecule may undergo photochemical reactions, causing structural changes, color and chemical properties to change; when heated, the temperature reaches a certain degree, the molecular structure will decompose and lose its original chemical properties, so it needs to be stored in a cool and dark place to maintain its stability.

This is the disodium salt, the full name is 8- (phenylamino) -5 - [ (E) - {4 - [ (E) - (5-sulfonaphthalene-1-yl) azo] naphthalene-1 - group} azo] naphthalene-1 - sodium sulfonate salt. Its chemical properties are as follows:
- ** Solubility **: Due to the sodium sulfonate group in the molecule, it has good water solubility. In water, the sodium sulfonate group is ionized, so that the substance is uniformly dispersed in an ionic state. This property makes it widely used in aqueous phase systems. For example, as an aqueous dye, it can be uniformly dispersed in water and effectively color substrates such as fabrics.
- ** Stability **: The azo group (-N = N-) in the structure is a chromophore, giving the substance color. However, the azo structure is not stable under specific conditions. In case of high temperature, strong oxidizing agent or reducing agent, it may decompose or change the structure, causing color change or loss of original properties. For example, in the high temperature printing and dyeing process, conditions need to be controlled to prevent the decomposition of azo structure from affecting the dyeing effect.
- ** Acidic and alkaline **: The sodium sulfonate group is weakly acidic and can release protons in aqueous solution, causing the pH value of the solution to drop slightly. This weak acidity makes it limited in some systems that need to control the pH value, and the pH needs to be adjusted to adapt to specific reactions or application environments.
- ** Optical properties **: Contains multiple conjugated systems, with significant optical activity, such as a specific absorption spectrum, with absorption peaks in the visible light region, showing color. This property makes it widely used in the field of dyes and pigments. According to the structure and length of the conjugate system, it presents a variety of colors to meet different dyeing and coloring needs.

To prepare disodium 8- (phenylamino) -5 - [ (E) - {4 - [ (E) - (5 -sulfonaphthalene-1 -yl) diazo] naphthalene-1 -yl} diazo] naphthalene-1 -sulfonate, the method is as follows:
First, all raw materials need to be prepared, among which naphthalene-based compounds, aniline and its derivatives are key materials. At the beginning of the reaction, specific naphthalene-based compounds are sulfonated. In this step, suitable sulfonating reagents, such as concentrated sulfuric acid or fuming sulfuric acid, are selected, and the temperature is precisely controlled, so that the sulfonation reaction reaches the expected check point and degree.
Then, the diazotization reaction is carried out. The sulfonated naphthalene-based product is taken and mixed with an appropriate amount of sodium nitrite under low temperature and acidic environment to form a diazonium salt. Among them, low temperature conditions are very important, because the properties of diazonium salts are unstable, and high temperature is easy to cause decomposition.
Furthermore, the coupling component is prepared. The aniline derivative is properly activated to make it have the activity of coupling with the diazonium salt.
Then, a coupling reaction is carried out. Under appropriate pH and temperature conditions, the obtained diazonium salt is mixed with the activated coupling component, so that the coupling reaction occurs between the two, and the key structure of the target product is constructed. This process requires strict control of the pH and temperature of the reaction system to ensure the smooth progress of the reaction towards the formation of the target product.
After the reaction is completed, the product is still mixed with many impurities. A series of separation and purification methods, such as filtration, extraction, crystallization, etc., are required to obtain high-purity disodium 8- (phenylamino) -5 - [ (E) - {4 - [ (E) - (5 -sulfonylnaphthalene-1 -yl) diazo] naphthalene-1 -yl} diazo] naphthalene-1 -sulfonate. Each step requires fine operation to obtain high-quality products.

Fu disodium 8- (phenylamino) -5- [ (E) - {4 - [ (E) - (5-sulfonaphthalene-1-yl) azo] naphthalene-1-yl} azo] naphthalene-1-sulfonate, there are many things to pay attention to when using this substance.
First, it is related to safety protection. This substance may have certain chemical activity. When exposed, wear suitable protective equipment, such as gloves, goggles, etc., to prevent it from coming into contact with the skin and eyes, causing discomfort and even injury. In case of inadvertent contact, rinse with plenty of water immediately and seek medical assistance according to the actual situation.
Second, about storage conditions. It should be stored in a dry, cool and well-ventilated place, away from fire and heat sources, to prevent its properties from changing due to environmental factors, affecting the use effect, or even causing danger. At the same time, it is necessary to avoid co-storage with strong oxidants, reducing agents and other easily reactive substances to prevent chemical reactions.
Third, operating standards during use are also extremely important. Before use, be sure to read the relevant instructions and operating procedures carefully, accurately control the dosage, and do not increase or decrease at will. And the operation should be carried out in a suitable environment such as a fume hood to disperse possible harmful gases and protect the health of the operator.
Fourth, the disposal after use should not be ignored. The remaining materials should not be discarded at will, and should be properly disposed of in accordance with relevant regulations to avoid pollution to the environment. The equipment used should also be cleaned to prevent residual substances from affecting subsequent experiments or production.
In conclusion, when using disodium 8- (phenylamino) -5- [ (E) - {4 - [ (E) - (5-sulfonaphthalene-1-yl) azo] naphthalene-1-yl} azo] naphthalene-1-sulfonate, it should be treated with caution in terms of safety protection, storage, operation and aftercare, and must not be negligent.