月: 2023年1月

What Is Sulfur Trioxide?

Figure 1. Basic Information on Sulfur Trioxide

Sulfur trioxide is an oxide of sulfur with the chemical formula SO₃.

It is synonymous with anhydrous sulfuric acid and serves as an intermediate in the contact process for manufacturing sulfuric acid.

Classified by the GHS as hazardous, sulfur trioxide poses risks such as severe skin and eye irritation, respiratory tract irritation, and potential dental damage from prolonged or repeated exposure. It is a specified substance under the Air Pollution Control Law but is exempt from several other regulations including the Industrial Safety and Health Law and the Poisonous and Deleterious Substances Control Law.

Uses of Sulfur Trioxide

Sulfur trioxide acts as an oxidizing and sulfonating agent, used in manufacturing ion exchange resins and sulfuric acid. Its role as a sulfonating agent extends to the industrial synthesis of dyes and neutral detergents.

As an intermediate in the contact process, sulfur trioxide is formed from sulfur dioxide in the presence of a catalyst and is crucial for producing high-purity concentrated sulfuric acid.

Properties of Sulfur Trioxide

Sulfur trioxide, a clear, colorless liquid at room temperature, has a melting point of 16.9°C and a boiling point of 45°C. It emits a strong pungent odor and forms fuming sulfuric acid when dissolved in concentrated sulfuric acid.

Its high hygroscopic nature means that sulfur trioxide can cause wood and cotton to ignite by dehydrating the water content, thus increasing flammability.

Structure of Sulfur Trioxide

Figure 2. Structure of Sulfur Trioxide

With a molar mass of 80.06 g/mol and a density of 1.92 g/cm³, sulfur trioxide typically has a planar equilateral triangle structure. The sulfur atom, at the center, exhibits an oxidation number of +6 and is surrounded by six electron pairs, most of which are non-bonding in nature. The three S-O bonds are equal in length, at 1.42 Å, and form a 120° angle (∠O-S-O).

Types of Sulfur Trioxide

Figure 3. Types of Sulfur Trioxide

Sulfur trioxide exists in three polymorphic forms: α-SO₃, β-SO₃, and γ-SO₃, each exhibiting unique behavior in the presence of trace amounts of water. The γ form aggregates to form a molecular crystal, while α and β forms can transition to each other under specific conditions, showcasing a range of structural complexities from fibrous to helical arrangements.

Other Information on Sulfur Trioxide

1. Synthesis of Sulfur Trioxide

Laboratory synthesis of sulfur trioxide involves the thermal decomposition of sodium hydrogen sulfate, among other methods. Industrially, the contact method predominates, involving the oxidation of sulfur dioxide at high temperatures to produce sulfur trioxide.

The lead chamber process, once a common method for sulfuric acid production, has become obsolete with the advent of the more efficient contact method.

2. Reaction of Sulfur Trioxide

As an anhydride of sulfuric acid, sulfur trioxide reacts exothermically with water, contributing to acid rain. It is also involved in the production of thionyl chloride through the reaction with sulfur dichloride.

What Is Molybdenum Trioxide?

Molybdenum trioxide (MoO₃), also known as molybdenum oxide (Ⅵ), is a widely produced molybdenum compound with CAS number 1313-27-5. It naturally occurs as the mineral molybdite and is notable for its applications due to its high heat resistance and strength.

Uses of Molybdenum Trioxide

Its uses span across being a catalyst, in the production of molybdenum metal and salts, and in enhancing the properties of metals like stainless steel by improving their heat resistance and strength. Additionally, it serves in the chemical industry as a catalyst for petroleum desulfurization and hydrocracking, among other applications.

Properties of Molybdenum Trioxide

A white or greenish-gray solid, molybdenum trioxide exhibits a melting point of 995°C and a boiling point of 1,155°C. It is soluble in ammonia water and alkali hydroxide solutions but insoluble in water, highlighting its unique chemical properties.

Types of Molybdenum Trioxide

Available as reagent products for research and as industrial materials, molybdenum trioxide caters to a diverse range of applications, from laboratory research to steel manufacturing additives.

1. Reagent Products

For laboratory use, reagent products are provided in various quantities and can include specialized forms like TEM diffraction specimens for electron microscopy.

2. Industrial Materials

In industrial applications, it is used in forms such as powders and briquettes for steel additives, pigments, and catalysts.

Other Information on Molybdenum Trioxide

1. Synthesis of Molybdenum Trioxide

Industrially, it is synthesized by roasting molybdenum disulfide, while laboratory synthesis often involves the reaction of molybdic acid solution with perchloric acid.

2. Chemical Reaction of Molybdenum Trioxide

It transitions from dihydrate to monohydrate upon losing hydration water and forms molybdate ions when dissolved in a base, showcasing its reactivity and utility in producing molybdenum metal.

3. Hazardousness of Molybdenum Trioxide and Regulatory Information

Despite its industrial value, molybdenum trioxide poses risks such as eye and respiratory irritation, potential carcinogenicity, and harm to aquatic life, necessitating strict regulatory compliance under various health and safety laws.

What Is Arsenic Trioxide?

Arsenic trioxide, with the chemical formula As₂O₃, is an oxide of arsenic known also by its CAS number 1327-53-3. It occurs naturally in minerals such as arsenopyrite and cladoclase but is highly toxic, evidenced by historical incidents like the Dorokyu Mine tragedy.

Uses of Arsenic Trioxide

Despite its toxicity, arsenic trioxide has been used as a rat poison, insecticide, pesticide, and in medicine for treating tooth decay and leukemia. Its industrial applications include manufacturing metallic arsenic, arsenic compounds, glass decolorization, dye production, and semiconductor doping.

Properties of Arsenic Trioxide

Arsenic trioxide is a colorless, odorless solid with a melting point of 312.2°C and a boiling point of 465°C. It sublimates into a toxic gas when heated and dissolves in water to form slightly acidic arsenite, showcasing unique chemical and physical properties.

Types of Arsenic Trioxide

Primarily available for research and development, arsenic trioxide is sold in various quantities suitable for laboratory use. It must be handled according to strict safety protocols due to its toxic nature.

Other Information on Arsenic Trioxide

1. Synthesis of Arsenic Trioxide

Produced by oxidizing arsenic sulfide or hydrolyzing arsenic trichloride, arsenic trioxide’s synthesis highlights its reactive nature.

2. Chemical Reaction of Arsenic Trioxide

As an amphoteric oxide, it reacts with both acids and bases, and strong oxidizers convert it to arsenic acid or arsenic pentaoxide, indicating its chemical versatility.

3. Toxicity of Arsenic Trioxide

Its classification under various GHS categories emphasizes the significant health risks associated with arsenic trioxide, including its potential for causing acute toxicity, eye irritation, genetic disorders, carcinogenicity, and reproductive toxicity.

4. Regulatory Information on Arsenic Trioxide

Regulated under numerous health and safety laws, arsenic trioxide’s management is subject to strict compliance requirements, reflecting its hazardous status.

What Is Phosphorus Trichloride?

Figure 1. Basic Information on Phosphorus Trichloride

Phosphorus trichloride (PCl₃) is a phosphorus chloride, known for its toxicity and hazardous nature, capable of causing fatal exposure at concentrations as low as 600 ppm. It is recognized for its irritant properties and acute toxicity by global safety standards and is regulated under various health and safety laws.

Uses of Phosphorus Trichloride

As a versatile trivalent phosphorus compound, phosphorus trichloride is used in a myriad of applications including as a flame retardant, antioxidant, plasticizer, in water treatment, and in the synthesis of organophosphine ligands and pharmaceutical intermediates. It serves as a precursor for many phosphorus-based compounds, including phosphoryl chloride and phosphorus pentachloride.

Properties of Phosphorus Trichloride

Figure 2. Hydrolysis of Phosphorus Trichloride

A colorless or yellow fuming liquid at room temperature, phosphorus trichloride has a pungent odor and reacts violently with water to produce hydrochloric acid and phosphonic acid, showcasing its corrosive nature towards metals.

Structure of Phosphorus Trichloride

With a molecular weight of 137.33 g/mol and a trigonal pyramidal structure, phosphorus trichloride exhibits significant chemical characteristics, including a specific dipole moment and a defined angle between its chlorine atoms, indicative of its reactive nature as a strong Lewis acid.

Other Information About Phosphorus Trichloride

1. Synthesis of Phosphorus Trichloride

Phosphorus trichloride can be industrially synthesized by chlorinating phosphorus under controlled conditions, with laboratory methods favoring red phosphorus for safety.

2. Synthesis of Phosphine Using Phosphorus Trichloride

It serves as a starting point for the synthesis of a wide array of organophosphine compounds, highlighting its importance in organic chemistry.

3. Reaction of Phosphorus Trichloride With Alcohols

Figure 3. Reaction of Phosphorus Trichloride

Phosphorus trichloride’s interaction with alcohols, depending on the presence of a base, can yield various phosphorus-containing organic compounds, demonstrating its role in synthetic organic chemistry.

4. Reaction of Phosphorus Trichloride With Amines

This compound’s reactions with amines and thiols further underline its utility in producing specialized chemicals for industrial applications.

5. Other Reactions of Phosphorus Trichloride

Its capability to undergo substitution reactions and act as a Lewis base illustrates the broad reactivity and application of phosphorus trichloride in chemical synthesis and industry.

What Is Boron Trifluoride?

Boron trifluoride is an inorganic compound with the chemical formula BF₃. It is found both as a dihydrate and an anhydrous form, with CAS registration numbers 7637-07-2 and 13319-75-0, respectively. Due to its irritant properties to mucous membranes, it requires careful handling. The complex formed with diethyl ether is a liquid often used as a Lewis acid.

Uses of Boron Trifluoride

Boron trifluoride has several major applications, including as a catalyst in Lewis acid reactions, in semiconductor manufacturing for doping, as a polymerization initiator, and in optical fiber production.

1. Catalysts

It readily forms complexes with Lewis bases, such as ammonia and diethyl ether, serving as a catalyst in organic synthesis for reactions like isomerization, alkylation, esterification, and condensation.

2. Semiconductor Manufacturing

In semiconductor manufacturing, it serves as a dopant in ion implantation and epitaxial growth of silicon, making it a P-type semiconductor.

3. Polymerization Initiator

As a polymerization initiator, it can polymerize vinyl phenols and their derivatives with limited molecular weight distribution and achieve cationic polymerization with living polymerization properties.

Properties of Boron Trifluoride

With a molecular weight of 67.82, it is a colorless gas at room temperature, while the dihydrate is a colorless liquid. It has a density of 0.00276 g/mL (1.64 g/mL for the dihydrate) and is soluble in water and various organic solvents. Its molecular structure consists of three fluorine atoms bonded to a boron atom in an equilateral triangle.

Molecular Structure of Boron Trifluoride

The molecular structure is an equilateral triangle, with strongly polarized covalent bonds, yet the molecule itself is nonpolar, attributed to the sp2 orbitals of boron atoms and its 3-fold symmetry.

Types of Boron Trifluoride

Available as a high-pressure gas for industrial use and as a methanol complex for research and development, it is supplied in steel cylinders and cardles. Proper storage and usage must comply with relevant safety and control laws.

1. High-Pressure Gas Products

Used in semiconductor manufacturing, pharmaceutical synthesis, and as a polymerization catalyst, these products are supplied in various container sizes and must be handled according to safety regulations.

2. Reagent Products for Research and Development

As a methanol complex salt, it is available in convenient laboratory volumes, suitable for storage at room temperature and available in reagent and analytical grades for various applications.

Other Information on Boron Trifluoride

1. Synthesis of Boron Trifluoride

It is industrially synthesized from boron oxide and hydrogen fluoride, with laboratory methods including decomposition of diazonium salts or reaction of sodium tetrafluoroborate with acids.

2. Reactivity of Boron Trifluoride

As a corrosive substance, it reacts with moisture to corrode certain metals but is inert to materials like teflon or polypropylene. It acts as a Lewis acid in chemical reactions, forming tetrafluoroborates or undergoing hydrolysis.

3. Regulatory Information on Boron Trifluoride

Classified as toxic and hazardous, it is subject to various regulatory requirements under safety, health, and environmental protection laws.

What Is Silicon Monoxide?

Silicon monoxide (SiO) is an inorganic compound known to exist in various forms, including as an interstellar molecule and as a mixture of silicon (Si) and silicon dioxide (SiO₂) in its solid state. Despite its complex nature, it is not specifically regulated by national safety laws.

Uses of Silicon Monoxide

SiO is gaining attention as a potential anode material for lithium-ion batteries due to its lower volume expansion rate during discharge, offering prospects for high-capacity, durable batteries. Research focuses on enhancing its utility by mixing or coating SiO with carbon.

Properties of Silicon Monoxide

As a gas, SiO forms diatomic molecules, but when cooled rapidly, it becomes a brown or black amorphous solid. It disproportionates into Si and SiO₂ upon exposure to air or water and is a poor conductor of electricity and heat. Despite its instability, SiO’s unique properties make it a subject of interest for various applications.

Structure of Silicon Monoxide

With a molar mass of 44.0849 g/mol and a density of 2.13 g/cm³, SiO exhibits a structure that shares characteristics with both Si and SiO₂. Research has revealed that SiO can form cyclic structures and disproportionates under high temperatures.

Other Information on Silicon Monoxide

1. Synthesis

SiO was first created in 1887 by reducing silica with charcoal. It can also be produced by heating Si and SiO₂ together or reducing SiO₂ with carbon monoxide or hydrogen.

2. Reactions

SiO interacts with chlorine, fluorine, and other molecules under specific conditions to form various compounds. These reactions demonstrate SiO’s versatility in forming different molecular structures, including linear and cyclic triatomic molecules.

What Is L-Leucine?

L-leucine, a branched-chain amino acid (BCAA) along with valine and isoleucine, is one of the 20 amino acids that constitute proteins. It has an isobutyl group on its side chain, making it highly hydrophobic. L-leucine, which exists in L- and D-forms, is found in proteins as the L-isomer.

As an essential amino acid, humans cannot synthesize L-leucine; it must be acquired through diet.

Physicochemical Properties of L-Leucine

1. Name

English name: L-leucine
IUPAC name: (2S)-2-amino-4-methylpentanoic acid
3-letter abbreviation: Leu
1-letter abbreviation: L

2. Molecular Formula

C₆H₁₃NO₂

3. Molecular Weight

131.17

4. Melting Point

293-295°C (decomposition)

5. Solvent Solubility

Slightly soluble in water, insoluble in ethanol.

6. Taste

Slightly bitter

Effects, Indications, and Uses of L-leucine

As a BCAA, L-leucine plays a crucial role in muscle fiber proteins. It activates enzymes needed for protein synthesis and induces muscle protein synthesis. Consequently, L-leucine and other BCAAs are popular supplements for strength training. Additionally, L-leucine is known to improve liver function, relieve stress, enhance glucose tolerance and insulin sensitivity, and promote hair growth. It is used in pharmaceuticals for amino acid supplementation and as a food additive.

Relationship Between L-Leucine Intake and Disease

L-leucine is abundant in various foods, making deficiency rare. However, insufficient intake may impair liver function and reduce insulin secretion. Excessive intake can disrupt the balance with other amino acids, potentially weakening the immune system.

Foods Rich in L-Leucine

Sources of L-leucine include liver, tuna, mackerel, chicken, dairy products, soy products, eggs, and yogurt.

What Is Copper Phosphate?

Copper phosphate Cu₃(PO₄)₂ exists in various hydrated forms including anhydrous, monohydrate, and trihydrate. Also known as tricopper bis-orthophosphate, it is recognized for its vibrant blue-green color and its CAS number for the anhydrous form is 7798-23-4.

Uses of Copper Phosphate

This compound serves multiple roles across different industries, including as an organocatalyst, fertilizer, emulsifier, corrosion inhibitor, metal protector, and feed additive. While its application as a metal protectant in phosphatization processes is limited, it is explored as an inorganic pigment due to its excellent color properties.

Properties of Copper Phosphate

Anhydrous copper phosphate has a molecular weight of 380.58 and forms a bright blue-green powder, whereas the trihydrate variant, weighing 434.63, presents as blue or olive-colored crystals. It is insoluble in water, ethanol, and acetone but dissolves in dilute hydrochloric acid and ammonia solutions.

Types of Copper Phosphate

Primarily marketed for research and development, copper phosphate is available in quantities suitable for laboratory use. The exact chemical composition can vary due to the presence of basic salts and production lot differences.

Other Information on Copper Phosphate

1. Synthesis

Synthesis methods include reacting phosphoric acid with copper hydroxide or diammonium phosphate with copper oxide at elevated temperatures.

2. Crystal Structure

Its structure forms a coordination polymer typical of metal phosphates, with the phosphate center adopting a tetrahedral geometry. Copper centers vary in coordination depending on the hydrate form.

3. Reactivity

Stable under recommended conditions, copper phosphate reacts with strong oxidizers and decomposes into hazardous products under certain conditions.

4. Toxicological Information

Classified as acutely toxic if ingested, handling requires caution to avoid skin and eye contact. It is regulated under various laws for its toxic nature, necessitating compliance with safety and health regulations during handling and disposal.

What Is Iron Phosphate?

Iron phosphate is a compound of iron combined with phosphate ions, existing mainly in two forms based on the oxidation state of iron: iron (II) phosphates and iron (III) phosphates. Iron (II) phosphates, known as ferrous phosphates, naturally occur as langanite. Iron (III) phosphates, or ferric phosphates, are found in forms such as strengite and coninckite.

Uses of Iron Phosphates

1. Agriculture and Pest Control

Iron phosphates are utilized in pesticides for snail and pest control due to their low toxicity to pets and wildlife, offering an environmentally friendly alternative to traditional pesticides.

2. Corrosion Resistance

They are applied in iron coating treatments to enhance the corrosion resistance of metals, providing a durable base for paint in automotive and other industrial applications.

3. Lithium-Ion Batteries

Lithium iron phosphates serve as cathode materials in lithium-ion batteries for electric vehicles, known for their safety and cost-effectiveness, despite having a lower energy density compared to other battery types.

Properties of Iron Phosphates

Iron (II) phosphates are paramagnetic and soluble in acid but not water, oxidizing in air to turn blue. Iron (III) phosphates are produced by reacting iron (III) salts with phosphoric acid, soluble in hydrochloric and sulfuric acids but insoluble in water.

Structure and Synthesis of Iron Phosphates

Iron (II) phosphates, with the formula Fe₃(PO₄)₂, and iron (III) phosphates, FePO₄, are synthesized through reactions involving phosphate solutions and iron salt solutions, leading to various hydrate forms.

Other Information on Iron Phosphates

1. Synthesis Methods

Crystals of iron phosphates can be precipitated by combining iron phosphate solutions with sodium acetate and disodium hydrogen phosphate, or by heating mixtures in sealed tubes under specific conditions.

2. Applications

Beyond their use in agriculture and coatings, iron phosphates find applications in milk powder as iron fortifiers and in non-halogenated flame retardants as catalysts and raw material.

What Is Zinc Phosphate?

Zinc phosphate, with the chemical formula Zn₃(PO₄)₂, is known for its use in various industrial applications. It exists as anhydride and tetrahydrate forms and is recognized for its toxicity to reproduction, specific organs upon repeated exposure, and the aquatic environment under GHS classifications.

Uses of Zinc Phosphate

1. Metal Treatment

Utilized for zinc plating and treatment on steel materials, zinc phosphate creates a protective film that prevents rust and enhances paint adhesion, especially valued in automotive coatings for its corrosion resistance.

2. Pigment

As a non-toxic alternative to lead and chrome pigments, zinc phosphate serves as an anti-corrosion pigment in various paint formulations, offering stability, neutralizing acidic corrosion ions, and widely used in both oil-based and water-soluble paints.

Properties of Zinc Phosphate

A white, odorless compound with a molecular weight of 386.13, insoluble in water and alcohols but soluble in dilute mineral acids and acetic acid. It decomposes at temperatures above 900°C without specific information on flash or boiling points.

Other Information on Zinc Phosphate

1. Safety

Regarded as harmful to fertility and unborn children, with potential to damage the blood system upon long-term exposure. It is highly toxic to aquatic life and classified as a deleterious substance, necessitating careful handling and adherence to safety guidelines.

2. First Aid Measures

Immediate medical attention is advised in case of inhalation, skin or eye contact, or ingestion. Use protective gear to manage spills and avoid potential health risks.

3. Handling Instructions

Recommended use of protective equipment, including glasses, masks, and gloves, with installations like eye wash stations and safety showers in work areas. Avoid inhalation and ensure proper hygiene practices post-handling.

4. Storage and Disposal

Store in sealed, intact containers and dispose of according to legal and local guidelines, ensuring environmental protection and safety measures during spill management.