月: 2023年4月

What Is Sulfolane?

Sulfolane is an organic compound, appearing as a colorless to yellowish-brown, clear to slightly cloudy liquid. It has the chemical formula C4H8O2S, a molecular weight of 120.00, and a CAS number of 126-33-0. It is produced by the catalytic reduction of Sulfolene, which is formed from the reaction of butadiene and sulfurous acid gas.

Uses of Sulfolane

1. Reaction Solvents

As a nonprotic polar solvent, Sulfolane is used in various chemical reactions including alkylation, acylation, aromatic substitution, and reduction reactions. It enhances reactivity by increasing the solvation of compounds and is favored for its low-side reaction profile.

2. Extraction Solvent

Sulfolane is utilized in the aromatic solvent extraction process, particularly in refining kerosene and diesel oil. It separates aromatic compounds like benzene, toluene, and xylene, which are in demand as chemical raw materials.

3. Polymer Solvent

It dissolves polymers like polyacrylonitrile and polyvinyl fluoride and is used in the polymerization of polyamide and polyacrylonitrile.

4. Additives

As a plasticizer, Sulfolane is added to various polymers like polyvinyl alcohol and polyamide. It also serves as a stabilizer and dispersing agent.

5. Lithium Battery Electrolyte

Due to its chemical stability and high boiling point, Sulfolane is used as an electrolyte in lithium-ion batteries.

6. Other Applications

Additional uses include cleaning solvents for semiconductor substrates, electrolytes in capacitors, and solvents for polarography.

Properties of Sulfolane

Sulfolane has a melting point of 27°C, a boiling point of 285°C, and a flash point of 174°C. It is highly soluble in water and miscible with most solvents. It shows excellent thermal stability up to 220°C, above which it gradually decomposes, emitting sulfurous acid gas. Sulfolane can form complexes with various compounds such as anhydrous cobalt(II) chloride and boranes.

What Is Skatole?

Skatole, also known as 3-methylindole, is a heterocyclic aromatic compound with the chemical formula C9H9N. It is found in elm and camphor tree trunks, beetroots, excrement, and coal tar. In the human body, it is produced from the metabolism of tryptophan by intestinal bacteria and contributes to the odor of feces.

Skatole is a white crystal that turns brown over time, with a melting point of 95°C and a boiling point of 265°C. It is insoluble in water but soluble in alcohols, benzene, and ether. When it reacts with potassium ferricyanide and sulfuric acid, it turns purple.

Uses of Skatole

Skatole is used at low concentrations in cosmetic fragrances, where it imparts a floral scent. Notably, it is a component of the jasmine fragrance. In higher concentrations, it has an unpleasant odor but is perceived as a sweet, soft scent at lower levels. It is also used as a flavoring and additive in cigarettes.

Properties and Synthesis of Skatole

The molar mass of Skatole is 131.17 g/mol. It is synthesized through Fischer indole synthesis, which involves heating phenylhydrazone with an acid catalyst. This process can utilize sulfuric or hydrochloric acid, as well as Lewis acids like boron trifluoride diethyl ether complex and zinc chloride.

Related compounds to Skatole include various methylated indoles, such as 1-methylindole, 2-methylindole, and others, each with distinct chemical properties and applications.

Safety and Handling

Due to its strong odor and potential toxicity, Skatole should be handled with appropriate protective equipment in a well-ventilated laboratory environment. It is also a flammable substance and should be stored away from light to prevent decomposition.

What Is Diglyme?

Diglyme, or diethylene glycol dimethyl ether, is an organic compound known for its use as a high-boiling-point hydrophilic electron donor solvent in synthetic organic chemistry. Its chemical formula is C6H14O3, indicating its structure as two methoxylated ethylene glycol molecules. It is recognized and classified under various safety laws due to its toxicity and potential hazards.

Uses of Diglyme

Figure 1. Example of Diglyme Coordination to Grignard Reagents

Diglyme serves various roles, including as a diluent, detergent, and reaction solvent, particularly with Grignard reagents and metal compounds. Its chelating ability to metal cations enhances reaction rates, making it valuable in reactions such as hydroborination with diborane.

Properties of Diglyme

Figure 2. Basic Information on Diglyme

With a molecular weight of 134.18, diglyme is a clear, colorless liquid at room temperature, featuring a melting point of -68°C and a boiling point of 162°C. It is miscible with water and various organic solvents, displaying stability under basic conditions but reacting violently with strong oxidants.

Types of Diglyme

Available for both research and industrial applications, diglyme is sold in volumes from 25mL to 500mL for R&D and in larger containers like 16 kg cans and 200 kg drums for industrial use. Some formulations may include stabilizers such as BHT or contain minor impurities like water.

Other Information on Diglyme

1. Synthesis of Diglyme

The synthesis involves the reaction between dimethyl ether and ethylene oxide in the presence of an acid catalyst, leading to diglyme’s production.

2. Chemical Reactions Using Diglyme as a Solvent

Figure 3. Example of Reaction Using Diglyme as a Solvent

Utilized for its ability to chelate metal cations, diglyme is a preferred solvent in various synthetic reactions, including reductions and hydroborination-amination processes.

3. Safety of Diglyme

As a hazardous substance, diglyme requires careful handling, appropriate protective equipment, and adherence to safety regulations due to its flammability and health risks.

What Is Dichloroacetic Acid?

Dichloroacetic acid, represented by the chemical formula CHCl₂COOH, is a variant of acetic acid. This colorless liquid is characterized by its pungent odor, higher acidity compared to acetic acid, and deliquescent properties. It is water-soluble and miscible with acetone, ether, and ethanol.

Formed as a disinfection byproduct during water purification, it arises when organic substances, bromine, and chlorine react in raw tap water. It is regulated under various laws as a poisonous and deleterious substance and a flammable liquid.

Uses of Dichloroacetic Acid

Dichloroacetic acid serves primarily as an intermediate in organic synthesis and pharmaceuticals, leading to the production of its salts and esters, test reagents for fiber analysis, and disinfectants. Its derivatives, including sodium dichloroacetate, are explored for anticancer properties and potential therapeutic effects.

Properties of Dichloroacetic Acid

Appearing as a colorless to light reddish-brown liquid, dichloroacetic acid has a molecular weight of 128.94 and a CAS number of 79-43-6. It has a melting point of 5-6°C, a boiling point of 194°C, and a density of 1.563 g/cm³. While stable under normal conditions, exposure to light can affect its stability, leading to decomposition products like carbon monoxide, carbon dioxide, and halides.

Other Information on Dichloroacetic Acid

1. Safety

GHS classifies it as posing risks of metal corrosion, acute dermal toxicity, skin and eye damage, mutagenicity, carcinogenicity, reproductive toxicity, specific target organ toxicity, and environmental hazards. It can cause severe skin and eye irritation, genetic mutations, carcinogenic effects, and damage to fertility or unborn children. Risks include respiratory system damage and, with long-term exposure, potential harm to the central nervous system, liver, pancreas, kidneys, and male reproductive organs.

2. First Aid

In case of inhalation, move the affected person to fresh air and seek medical attention if symptoms persist. For skin contact, remove contaminated clothing and wash the area with soap and water. If ingested, rinse the mouth and seek immediate medical help, especially if the person is unconscious. Always bring the chemical’s SDS and other relevant manuals when seeking medical assistance.

3. Handling Methods

Ensure proper ventilation and local exhaust systems in indoor workspaces. Provide safety showers, and eye washing stations, and wear appropriate protective gear, including masks, gloves, and goggles. Follow proper disposal methods for contents and containers, and maintain hygiene by avoiding consumption of food or beverages and washing thoroughly after handling.

4. Storage

Store in cool, well-ventilated, light-protected, sealed areas. Use corrosion-resistant containers and keep away from incompatible materials.

5. Water Quality Standards

Tap water standards mandate a maximum dichloroacetic acid concentration of 0.03 mg/L. Given its formation during water purification, eliminating it from tap water is challenging.

What Is Diisopropylethylamine?

Diisopropylethylamine, also known as N,N-diisopropylethylamine, is an organic compound featuring two isopropyl groups and an ethyl group attached to a nitrogen atom. It is a common reagent in pharmaceutical manufacturing and organic synthesis research, valued for its sterically bulky structure.

The primary method for producing diisopropylethylamine involves the ethylation of diisopropylamine with diethyl sulfate or ethyl iodide.

Uses of Diisopropylethylamine

As a low nucleophilic base with bulky isopropyl groups, diisopropylethylamine is primarily used as a reagent in organic synthesis. It finds application in:

• Synthesis of biologically active substances, particularly peptides.
• Production of oxime resins for solid-phase synthesis of cyclic peptides.
• Manufacture of benzotriazole derivatives like 1-hydroxybenzotriazole (HOBt) and 1-hydroxy-7-azabenzotriazole (HOAt), used as coupling reagents in peptide synthesis.

Diisopropylethylamine is also widely used in laboratory research as a bulky base in organic reactions.

Properties of Diisopropylethylamine

Chemical Formula: C8H19N; CAS No: 7087-68-5; Molecular Weight: 129.24 g/mol; Melting Point: -50°C; Boiling Point: 127°C. It is soluble in ethanol and acetone but insoluble in water.

Aliases and Safety Information for Diisopropylethylamine

Also known as N-ethyl diisopropylethylamine or Hünig’s Base (named after German chemist Siegfried Helmut Hünig), DIPEA is a flammable and hazardous material. It requires careful handling with protective gear, especially in well-ventilated environments, due to its pungent odor. For storage, it should be kept in a cool, dark place, away from light to prevent decomposition.

Considering its toxicity to aquatic life, disposal of diisopropylethylamine should be conducted through specialized waste disposal services to mitigate environmental impact.

What Is Diazonium?

Diazonium refers to nitrogen compounds characterized by an NN triple bond, making them highly reactive and often unstable. These compounds typically exist as diazonium salts due to their monovalent cationic nature. Owing to their inherent explosiveness, diazonium compounds are usually utilized in solution within reaction systems, without isolation.

Stabilization of diazonium compounds can be achieved by using aryl groups with electron-withdrawing groups as substrates and anions like tetrafluoroborate (BF3). A commercially available example is p-Morpholinobenzenediazonium Tetrafluoroborate.

Uses of Diazonium

Diazonium compounds, due to their reactive NN triple bond, primarily serve as intermediates in various chemical reactions. Key reactions involving diazo groups include aromatic substitution reactions like the Sandmeyer reaction and diazo coupling.

These reactions are crucial in the synthesis of pharmaceuticals, functional materials, and azo dyes. Azo dyes, which constitute over half of all synthetic dyes, are produced through coupling reactions between diazonium compounds and phenols or aromatic amines. The significance of diazonium compounds, especially in the industrial production of azo dyes, underscores their importance in the field of chemical synthesis.

What Is Diacetyl?

Diacetyl is a yellow-green liquid known for its strong, characteristic odor. Its chemical formula is C₄H₆O₂, with a molecular weight of 86.09, and its CAS number is 431-03-8. It comprises two acetyl groups linked to a carbonyl group’s carbon. The IUPAC name for diacetyl is 2,3-butanedione.

Present naturally in alcoholic beverages, diacetyl is also added to various foods as a flavoring agent, imparting a buttery flavor due to its butter-like aroma when diluted.

Uses of Diacetyl

Diacetyl finds extensive use in the food industry, particularly as a flavoring agent in margarine, butter and cheese-flavored snack foods, wine, and vinegar. It’s also employed as a liquid flavoring in e-cigarettes. During the brewing process of beer and other alcoholic beverages, diacetyl is naturally produced by microorganisms. The brewing process is controlled to manage diacetyl levels, as excessive amounts can negatively impact the beverage’s aroma.

Properties of Diacetyl

Diacetyl boasts a melting point of -2°C, a boiling point of 88°C, and a density of 0.99 g/mL. It is flammable, with a flash point of 6°C and a spontaneous combustion point of 365°C. Its explosive vapor-air mixtures and solubility in water (20 g/100 mL) make it notable, along with its miscibility in most organic solvents. Diacetyl is also a natural fermentation byproduct, formed through thiamine pyrophosphate-mediated condensation of pyruvate and acetyl CoA in some bacteria.

Structure of Diacetyl

Diacetyl and other vicinal diketones are distinguished by the long carbon-carbon bond between the two carbonyl centers, measuring 1.54 Å compared to 1.45 Å in 1,3-butadiene. This bond elongation results from the repulsive forces between the polarized carbonyl carbon centers.

Other Information on Diacetyl

1. Diacetyl Production Method

Diacetyl is primarily produced by dehydrogenating 2,3-butanediol, with acetoin serving as an intermediate. An alternative method involves hydrolyzing methyl ethyl ketone with sodium nitrite and hydrochloric acid.

2. Regulatory Information

Although not designated under specific environmental or poisonous substance control laws, diacetyl is classified as a flammable liquid, and a hazardous and noxious substance, requiring careful handling.

3. Handling and Storage Precautions

Handling and storage precautions include keeping the container tightly closed in a cool, dry, and well-ventilated area, away from heat and ignition sources. It’s important to wear appropriate protective gear and to take special precautions due to the risk of irreversible obstructive pulmonary disease upon exposure.

What Is Diacetone Alcohol?

Diacetone alcohol is an organic compound with the chemical formula C₆H₁₂O₂. It combines ketone and alcohol functional groups, resembling condensed acetone in its molecular structure. Its CAS number is 123-42-2.

Uses of Diacetone Alcohol

Diacetone alcohol serves as a solvent for fats, oils, resins, and nitrocellulose, and is used in printing inks, coating resins, metalworking fluids, lubricants, and cleaning agents. It is a high-boiling point solvent with low vapor pressure, ideal for reducing the viscosity of heavy organic liquids and minimizing temperature effects on viscosity.

It is also utilized in the production of cellulose ester lacquers, printing inks, alkyd and vinyl resin coatings, epoxy resins, water hardening agents, photographic films, anti-icing agents, artificial silks, and leathers. Additionally, diacetone alcohol is a precursor for various organic compounds such as methyl isobutyl ketone (solvents and paints), methyl isobutyl carbinol (electronic materials), and hexylene glycol (penetrating agents and detergents).

Properties of Diacetone Alcohol

Figure 1. Basic Information on Diacetone Alcohol

Diacetone alcohol has a molecular weight of 116.16, melts at -44°C, and boils at 167.9°C. This colorless, virtually odorless liquid is generally stable under normal handling conditions. It is soluble in water at 1.00 x 10⁶ mg/L and miscible with alcohols and ethers. Its density is 0.93 g/mL, with a flash point of 66°C and a spontaneous combustion temperature of 603°C.

Types of Diacetone Alcohol

Diacetone alcohol is marketed both as a research reagent and an industrial chemical.

1. Reagent Products for Research and Development

For research and development, diacetone alcohol is offered in various quantities, including 500 mL and 15 kg, tailored for laboratory use. These products are easily stored at room temperature and provide a cost-effective option for researchers.

2. Industrial Chemicals

As an industrial chemical, diacetone alcohol is primarily used as a solvent in applications such as paints, gravure inks, adhesives, insecticides, and photographic film production. It is available in 16 kg oil cans, 196 kg drums, and 1,000 L containers.

Other Information on Diacetone Alcohol

1. Synthesis of Diacetone Alcohol

Figure 2. Synthesis of Diacetone Alcohol

Diacetone alcohol is produced industrially by the dimerization of acetone through aldol condensation, using a base such as barium hydroxide as a catalyst.

2. Chemical Reaction of Diacetone Alcohol

Figure 3. Dehydration Reaction of Diacetone Alcohol

Upon heating, combustion, or contact with acids, bases, or amines, diacetone alcohol decomposes into acetone and mesityl oxide. It reacts violently with oxidizing agents, potentially forming flammable or explosive gases. Hazardous by-products include acetone, methyl alcohol, and hydrogen.

3. Diacetone Alcohol Hazard and Regulatory Information

Diacetone alcohol is classified under GHS as a flammable liquid, skin, and eye irritant, toxic to reproduction, and potentially harmful to specific organs. It is regulated under various laws, requiring careful handling and compliance with safety and environmental regulations.

What Is Silanol?

Silanol broadly refers to compounds featuring a hydroxyl group (-OH) bonded to a silicon atom. Specifically, in its narrower definition, silanol is a volatile, colorless liquid compound with the chemical formula SiH3OH, also known as silyl alcohol.

It acts as an intermediate in the formation of siloxane (silicone) compounds, typically produced through the hydrolysis of chlorosilane and alkoxysilane. Silanol is known for its instability, as it is prone to dehydration and condensation, making it challenging to isolate.

Uses of Silanol

While traditionally silanol has been difficult to synthesize industrially due to its instability, there have been recent advances. For instance, orthosilicic acid (Si(OH)4), a type of silanol, and its oligomers have been synthesized in a stable form. This breakthrough opens up potential avenues for the production of silicone compounds using such materials.

Despite its instability, silanol’s role as an intermediate in silicone production is crucial, especially in the context of developing advanced materials and compounds in chemical industries.