月: 2023年1月

What Is Hexanol Alcohol?

Hexanol alcohol, a 6-carbon alkyl alcohol, includes 1-hexanol (n-hexyl alcohol or hexyl alcohol) as one of its most common forms. This organic compound is a colorless liquid derived from coconut oil and palm oil and as an intermediate in cellulose conversion. Classified as safety laws, it requires careful handling.

Uses of Hexanol Alcohol

As a versatile solvent, hexanol alcohol is used in the production of plasticizers, and organic synthesis, and as a surfactant, antiseptic, disinfectant, and finishing agent for textiles and leather. It also serves as an odorant in olfactory studies, and the manufacture of air fresheners and fragrances. 3-hexanol alcohol contributes the aroma of pineapple to food additives and is employed in cosmetics for its antifoaming and fragrance properties.

Properties of Hexanol Alcohol

1-hexanol alcohol exhibits limited water solubility but dissolves well in alcohols and ethers. It has a density of 0.8153 g/cm³ at 25°C, with a melting point of -51.6°C, and a boiling point of 157°C. The linear structure of hexanol alcohol also encompasses 2-hexanol and 3-hexanol, with varying densities and boiling points.

Structure of Hexanol Alcohol

Hexanol alcohol is structured with one hydrogen of hexane replaced by a hydroxy group, resulting in 17 isomers. These include eight primary alcohols, six secondary alcohols, and three tertiary alcohols, depending on the hydroxy group’s position and branching.

Other Information on Hexanol Alcohol

1. 1-Hexanol Synthesis

Industrial synthesis of 1-hexanol alcohol involves oligomerization of ethylene, with triethylaluminum used for oxidation. Fractional distillation is required to separate alcohols of different chain lengths. Alternatively, 1-hexanol can be synthesized through the hydrogenation of hexanal produced in the hydroformylation of 1-pentene.

2. Structural Isomer of Hexanol Alcohol, a Primary Alcohol

Primary alcohol hexanol includes 1-hexanol and variants like 2-methyl-1-pentanol, with structural diversity extending to hexanol alcohols with different carbon chain lengths and branching.

3. Structural Isomers of the Secondary Alcohol Hexanol Alcohol

Secondary alcohol hexanol variants include 2-hexanol and 3-hexanol, among others, highlighting the complexity of hexanol’s isomeric structures.

4. Structural Isomers of the Tertiary Alcohol Hexanol Alcohol

Tertiary alcohol hexanol encompasses isomers such as 2-methyl-2-pentanol, illustrating the diversity of hexanol alcohol’s molecular configurations.

What Is Hexanal?

Hexanal, an organic compound, is a chained aliphatic aldehyde with the chemical formula C6H12O and CAS number 66-25-1.

It has a molecular weight of 100.16, a melting point of -56 °C, and a boiling point of 131 °C. At room temperature, hexanal is a clear, colorless liquid with a distinct odor reminiscent of green leaves and manure. It is the source of the characteristic foul odor in soybeans and grass. Soluble in ethanol and acetone, hexanal is insoluble in water, with a density of 0.8335 g/cm³.

Uses of Hexanal

Hexanal has several applications, including the following:

• Flavoring agent in alcoholic beverages, butter, and cosmetics
• Component in dyes
• Raw material for plasticizers and synthetic resins
• Used in pesticide production

It is also utilized to produce 1-hexanol, a plasticizer raw material, via hydrogenation. Despite its foul odor, hexanal is an ingredient in fragrances, imparting green flavors to fruit flavors and fresh notes to dairy and rum flavors.

Principle of Hexanal

Hexanal’s synthesis and chemical properties are explained as follows:

1. Synthesis of Hexanal

In living organisms, hexanal is produced by the oxidation of fatty acids. In soybeans, for example, linoleic acid is converted to hexanal via lipoxygenase and hydroperoxide lyase. Industrially, it’s obtained through the hydroformylation of 1-pentene.

2. Chemical Properties of Hexanal

Hexanal is prone to oxidation and polymerization, especially in acidic conditions, due to its formyl group (-CHO). In soybeans, it oxidizes to caproic acid, and in synthetic chemistry, it is used in Wittig and Aldol reactions. Despite its reactivity, hexanal is stable under proper storage and handling.

3. Hexanal in the Real World

Hexanal forms in foods during cooking due to lipid peroxidation, contributing to the deteriorating odor in products like instant noodles and coffee milk. It also appears in juices and olive oil. With a low flash point of 32 °C, it is highly flammable and must be stored away from ignition sources. It is subject to various safety regulations due to its hazardous nature.

Types of Hexanal

Hexanal is available in forms for industrial use and as research reagents. Industrial products are typically sold in large capacities, such as drums and oil cans, for use in organic synthesis and fragrance production. Research reagents are available in various smaller volumes for laboratory use. Some are stored at room temperature, while others require refrigeration. Given its high flammability, caution is advised during storage and transportation.

What Is Furan?

Furan is a colorless liquid with an odor resembling chloroform. It occurs naturally in pine tar and is also produced through the heating and decarboxylation of 2-furan carboxylic acid, which is derived from the oxidation of furfural.

Furan is soluble in ethanol, ether, and petroleum ether, and slightly soluble in water. It is stable in the presence of alkalis but reactive with inorganic acids. Furan’s relatively low aromaticity and high density make it prone to Diels-Alder reactions.

When hydrogenated using a palladium catalyst, furan yields tetrahydrofuran. It can also react with ammonia in the presence of a dehydrating agent to form pyrrole, and with hydrogen sulfide to form thiophene.

Furan vapor possesses anesthetic properties and requires careful handling.

Uses of Furan

Furan serves as an intermediate in synthesizing various heterocyclic compounds and is widely utilized in producing synthetic resins, solvents, and detergents.

Tetrahydrofuran, produced by hydrogenating furan with a palladium catalyst, is employed in organic solvents and for other applications.

By reacting furan with ammonia and using alumina as a catalyst, pyrrole is formed, which is used as a detection reagent.

When furan is heated with hydrogen sulfide in the presence of a dehydrating agent, thiophene is produced.

What Is Hydroquinone?

Hydroquinone, a divalent phenol, is also known as p-dihydroxybenzene or quinol. It can be synthesized by reducing benzoquinone with sulfurous acid.

Most hydroquinone is produced through the diisopropylbenzene process, utilizing benzene and propylene. It may cause allergic contact dermatitis as a side effect.

Uses of Hydroquinone

Hydroquinone serves as an intermediate raw material in the manufacture of photographic developers, dyes, and pharmaceuticals, and as an antioxidant for rubber and electronic materials. It is also employed as an analytical reagent for determining phosphorus, arsenic, and silicic acid.

As an antioxidant, hydroquinone shows excellent inhibitory effects on the polymerization of monomers like acrylonitrile, acrylates, and styrene when used in very small amounts.

In cosmetics, hydroquinone is used as a hair colorant, skin bleach, antioxidant, and fragrance component. However, its use in concentrations above 2% is restricted due to suspected carcinogenic properties.

Properties of Hydroquinone

At normal pressure, hydroquinone has a melting point of 172°C, a boiling point of 287°C, and a density of 1.3 g/cm³. It is soluble in water, ethanol, and ether, but not in cold benzene.

Being highly reductive, hydroquinone can reduce alkaline silver salt solutions and Fehling’s solution, and it discolors upon gradual oxidation in air.

Hydroquinone is a colorless or white crystal with the chemical formula C₆H₆O₂, a molar mass of 110.11 g/mol, and the specific formula C₆H₄(OH)₂.

Other Information on Hydroquinone

1. Synthesis of Hydroquinone

Hydroquinone can be produced by oxidizing phenol, using hydrogen peroxide with beta-zeolite (H-BEA) as a catalyst and diethyl ketone as an auxiliary catalyst. This method also yields catechol, but selectivity can be improved by ion-exchanging H-BEA with alkaline earth metals.

Another production method is the Elbs persulfate oxidation, utilizing potassium persulfate to oxidize phenol to hydroquinone.

2. Oxidation of Hydroquinone

Easily oxidized to p-benzoquinone, hydroquinone’s reductive properties have given it its name through the reduction process of p-benzoquinone, also known as 1,4-benzoquinone, a single six-membered carbon ring quinone with the molecular formula C₆H₄O₂.

3. Regioisomers of Hydroquinone

Hydroquinone has two regioisomers, catechol and resorcinol. Catechol, with hydroxy groups in the ortho position on the benzene ring, is also known as pyrocatechol. Resorcinol has hydroxy groups in the meta position and is used in tire cord adhesives, UV absorbers for resins, and flame retardants.

What Is Hydroxylamine Hydrochloride?

Hydroxylamine hydrochloride is the hydrochloride salt of hydroxylamine.

A highly concentrated solution of hydroxylamine can react with itself or with iron ions, leading to explosions. It should, therefore, be transported and used in a diluted state; concentrations below 15% are considered safe.

Hydroxylamine is classified as a priority chemical substance and a hazardous material under various safety laws.

Uses of Hydroxylamine Hydrochloride

In organic synthesis, hydroxylamine hydrochloride is used to synthesize oximes and hydroxamic acids from carboxylic acids, and N- and O-hydroxylamines. It is also utilized in carbon-carbon double bond (C=C) addition reactions.

Industrially, it serves to remove bromine during the extraction of lignin from biomass. It acts as a surface treatment agent in paints and semiconductors and as a raw material for pharmaceuticals and agrochemicals. In the rubber and plastics industries, it is employed as an antioxidant, vulcanization accelerator, and radical scavenger. It contributes to the production of nylon and is used as a fixative in textile dyeing, a dyeing aid, an antioxidant, and a dye-fixing agent in color films.

Hydroxylamine hydrochloride is significant in the nitrogen cycle and wastewater treatment, functioning as a biological intermediate in nitrification and anaerobic ammonia oxidation.

Properties of Hydroxylamine Hydrochloride

Hydroxylamine hydrochloride appears as a white crystal. It is readily soluble and ranks among the strongest reducing agents. It dissolves in water and exhibits strong acidity, gradually decomposing in aqueous solutions and moist air. It is also soluble in liquid ammonia, slightly soluble in methanol and ethanol, but insoluble in ether.

It poses an explosion hazard near fire or heat sources and may explode if heated above 115°C. It decomposes at 152°C and can form oximes with aldehydes and ketones. Hydroxylamine hydrochloride is also a precursor to hydroxylamine.

Structure of Hydroxylamine Hydrochloride

Hydroxylamine hydrochloride, with the chemical formula [NH₃OH]Cl, has a molecular weight of 69.49 g/mol and a density of 1.68 g/cm³. The bond distance between nitrogen and oxygen (N-O) is approximately 1.45 Å. It is known by other names such as hydroxyamine hydrochloride, and hydroxylammonium chloride, and is a monoclinic and ionic crystal containing [NH₃OH]⁺ ions.

Hydroxylamine hydrochloride is produced through the reaction of nitric acid with HCl following electrolytic reduction, or from the reaction of BaCl₂ with aqueous hydroxylammonium sulfate.

Other Information About Hydroxylamine Hydrochloride

1. Related Compounds to Hydroxylamine Hydrochloride

Hydroxylamine is typically managed as an aqueous solution or as hydroxylamine hydrochloride. Its empirical formula is NH₂OH, sharing structural characteristics with both ammonia and water.

Its molecular weight is 33.030 g/mol, with a melting point of 33°C, decomposing at 58°C, and a density of 1.21 g/cm³ at 20°C. Hydroxylamine, at room temperature, is a crystalline solid and exhibits hygroscopic and deliquescent properties.

2. Hydroxylamine Salts

Hydroxylamine salts result from the neutralization of hydroxylamine with acids. Beyond hydroxylamine hydrochloride, these include hydroxylamine sulfate.

The chemical formula for hydroxylamine sulfate is H₂SO₄・(NH₂OH)₂, with a molecular weight of 164.14 g/mol. It decomposes at 170°C, appearing as a white crystal, soluble in water and strongly acidic.

What Is Naphthalene?

Naphthalene is an aromatic hydrocarbon with a bicyclic fused ring. When exposed to ultraviolet light, naphthalene emits a purple fluorescence. 

Naphthalene has a distinctive odor and sublimates at room temperature. Naphthalene is insoluble in water, but soluble in many organic solvents, such as ethanol, ether, and benzene.

Naphthalene is a useful synthetic intermediate when it undergoes elementary, sulfonation, nitration, and other reactions.

Naphthalene is the most abundant component in coal tar and is obtained by refining coal tar. When naphthalene oil extracted from coal tar is forced to cool, naphthalene precipitates as crystals.

Uses of Naphthalene

Naphthalene is highly volatile even at room temperature and is widely used in daily life as an insecticide and deodorant. Phthalic anhydride, which is produced from naphthalene, is also used as raw material for polyester fiber.

Naphthalene is also widely used as a dye intermediate, synthetic resin, insecticide, sterilizer, fuel, surfactant, dispersant for emulsion polymerization that gives rubber flexibility, and raw material for organic chemical synthesis such as organic pigments.

Hydrogenation of naphthalene yields tetralin and decalin, which are useful solvents for chemical synthesis and the production of ink paints.

What Is Sodium Methylate?

Sodium methylate, a white to almost white powder or mass, has the chemical formula CH3ONa, a molecular weight of 54.02, and CAS No. 124-41-4. It melts at 127 °C, is flammable, soluble in methanol, and decomposes in water.

Classified as a flammable and spontaneously combustible substance, sodium methylate is considered hazardous under the 2012 OSHA Hazard Communication Standard (29 CFR 1910.1200). It is categorized as a flammable solid, self-heating substance, corrosive to metals, and poses risks of acute oral toxicity, skin corrosion/irritation, serious eye damage/irritation, and specific target organ toxicity (single exposure).

Uses of Sodium Methylate

Sodium methylate is widely used in organic synthesis in the pharmaceutical, fragrance, and dye industries, serving as a reduction catalyst. It is also employed in the food industry to alter the physical properties of fats and oils in products like margarine and shortening. Furthermore, it has applications in the production of biodiesel fuel, as indicated by registered patents.

What Is Sodium Ethylate?

Sodium ethylate, a white to light brown powder or mass, has the chemical formula C2H5ONa, a molecular weight of 68.05, and a CAS number of 141-52-6. Its melting point is 300 °C, and it has a density of 0.868. Sodium ethylate is soluble in ethanol and decomposes in water.

Classified as a flammable and spontaneously combustible substance, sodium ethylate is considered hazardous under the 2012 OSHA Hazard Communication Standard (29 CFR 1910.1200) and the Globally Harmonized System (GHS). It poses risks including acute toxicity, skin corrosion/irritation, serious eye damage/irritation, specific target organ toxicity (single exposure), self-heating, and flammability.

Uses of Sodium Ethylate

Sodium ethylate is commonly used in organic synthesis as a condensing agent and a reducing agent as well as a catalyst. As an alkoxide (an organic base with an alkyl group), it is soluble in organic solvents and forms an alkoxide anion. This anion plays a crucial role in nucleophilic reactions, such as alkoxylation, by taking a proton from the reactant to induce the reaction. The condensing agent facilitates this process.

What Is Sodium?

Sodium, an alkali metal with the atomic number 11 and symbol Na, is known for its high reactivity. Its atomic weight is 22.99. Sodium is commonly found in nature in the form of sodium chloride (table salt), carbonates, and nitrates, and is produced industrially through the electrolysis of molten salts.

Applications of Sodium

Due to its reactivity, sodium serves as a reducing agent or catalyst in metal refining processes. Its low melting point and good thermal conductivity make it suitable as a coolant in fast-breeder nuclear reactors. Sodium lamps, utilized in highway and tunnel lighting, along with its use in soap, highlight its presence in daily life. Additionally, it plays a crucial role in maintaining normal muscle and nerve function in the human body.

Physical and Chemical Properties

Sodium is a soft, silvery-white metal with a melting point of 98°C and a boiling point of 883°C. It is lighter than water, with a specific gravity of 0.97. Sodium reacts explosively with water, acids, and bases, and oxidizes in air, requiring storage in kerosene to prevent reaction.

Molecular Structure and Isotopes

At room temperature, sodium adopts a body-centered cubic structure with an electron configuration of [Ne] 3s¹. It transforms under high pressure, becoming transparent. Sodium has 20 known isotopes, but only ²³Na is stable, with ²²Na and ²⁴Na occasionally detected in rainwater.

Industrial Production

1. Electrolysis Methods

Sodium is primarily produced via electrolysis of molten salt, using either the Castner or Downs’ process. The Castner process electrolyzes sodium hydroxide, while the Downs process uses sodium chloride, potentially with calcium chloride or potassium chloride to lower the melting point.

2. Chemical Reactions

Sodium’s interaction with water forms hydrogen gas and sodium hydroxide. It can also form sodium hydride when heated with hydrogen and reacts with alcohols, phenols, and carboxylic acids to produce alkoxides. Sodium’s reduction properties facilitate the extraction of metals like titanium, thorium, tantalum, and zirconium.

What Is Trimethylolpropane?

Trimethylolpropane (TMP) is a solid organic compound, colorless to white, and slightly odoriferous at room temperature. It is available in both powder and pellet forms. TMP is also known as 2-ethyl-2-hydroxymethyl-1,3-propanediol or 1,1,1-tris(hydroxymethyl)propane.

It is completely soluble in water, alcohols, and acetone, and partially soluble in carbon tetrachloride, chloroform, and ether. However, it is insoluble in aromatic hydrocarbons. TMP is flammable and reacts violently with strong oxidizing agents, necessitating careful handling and storage.

Uses of Trimethylolpropane

Trimethylolpropane serves as a raw material and intermediate in the production of polymer materials, including alkyd resins, polyurethanes, plasticizers, surfactants, wetting agents, fiber processing agents, and photographic chemicals. Its three hydroxyl groups allow for versatile chemical reactions, such as esterification with acrylic acid to form a cross-linker for radical polymerization. TMP is also used to cross-link urethane resins by reacting its hydroxyl groups with isocyanate groups (-N=C=O) to form a urethane bond.

Additionally, trimethylolpropane diallyl ether, where two hydroxyl groups are modified with an allyl group (-CH2CH=CH2) via an ether bond, is commercially available. This derivative is utilized in unsaturated polyester resins, alkyd resins, and as a cross-linking agent for various other resins.