月: 2023年7月

What Is Magumit?

Magumit is a drug prescribed as an antacid and laxative.

The name Magumit is a trade name; the generic name is magnesium oxide. It is sold by various pharmaceutical manufacturers.

Its main indications include antacid action and improvement in diseases such as gastric and duodenal ulcers, gastritis, and upper gastrointestinal dysfunctions, improvement of constipation, and prevention of the formation of calcium oxalic stones in the urinary tract. Because it is a prescription drug, a doctor’s prescription is required to purchase it.

Historically, it is said that German physician Philip Franz von Siebold brought it to Japan when he came to Japan in 1823.

Uses of Magumit

Magumit is a drug administered to improve gastric and duodenal ulcers, gastritis, and upper gastrointestinal dysfunctions through its antacid action, to treat constipation through its laxative action, and to prevent urinary tract stones.

As a laxative, it does not directly stimulate the movement of the intestinal tract, but instead works by increasing the absorption of water in the intestinal tract, thereby aiding peristalsis of the large intestine and promoting defecation.

Properties of Magumit

The active pharmaceutical ingredient in Magumit is magnesium oxide (CAS number 1309-48-4), which itself is a colorless crystal or powder at room temperature with a molecular weight of 40.30, a melting point of 2852°C, and a boiling point of 3600°C. Magnesium oxide has a density of 3.65 g/kg and a viscosity of 3.65 g/kg. It has a density of 3.65 g/mL and is virtually insoluble in water and ethanol.

Magnesium oxide is produced by the combustion of metallic magnesium, thermal decomposition of magnesium hydroxide or magnesium carbonate, and other methods.

Types of Magumit

Magumit is a prescription drug that requires a doctor’s prescription, and is manufactured and sold by a variety of pharmaceutical manufacturers, including Magumit Pharmaceuticals, Maruishi Pharmaceuticals, Shioe Pharmaceuticals, and Nippon Shinyaku.

In addition to Magumit, many other manufacturers sell magnesium oxide preparations, and there are also over-the-counter drugs that do not require a prescription.

Magumit is available in white tablet form, in 200 mg, 250 mg, 330 mg, 50 mg, and other forms.

Other Information on Magumit

1. Pharmacological Action of Magumit

As an antacid, 1 g of magnesium oxide can neutralize approximately 500 mL of 0.1 mol/L hydrochloric acid. It exerts its antacid effect in the stomach and is considered less irritating because it does not produce carbon dioxide. Since it is insoluble in water, its antacid action is slow-acting and has a longer duration of action compared to sodium bicarbonate.

As a laxative, it becomes bicarbonate in the intestine, increasing osmotic pressure in the intestine and drawing water into the intestinal lumen. This softens the intestinal contents and causes the intestinal contents to expand, stimulating dilation of the intestinal tract and promoting defecation.

2. Side Effects of Magumit

A serious side effect of Magumit is hypermagnesemia. The risk is particularly high in patients with renal dysfunction, so the drug is administered with caution to patients with renal dysfunction.

Symptoms of hypermagnesemia include nausea, vomiting, dry mouth, hypotension, bradycardia, skin flushing, muscle weakness, and somnolence, and in severe cases, respiratory depression, impaired consciousness, arrhythmia, and cardiac arrest. In severe cases, respiratory depression, impaired consciousness, arrhythmia, and cardiac arrest may occur. If abnormality is observed, it is necessary to discontinue the administration of magnesium.

If abnormalities are observed, administration should be discontinued. In addition, cases of hypermagnesemia in elderly patients have been reported, resulting in serious outcomes.

Therefore, the dosage should be reduced in elderly patients, and careful monitoring, such as a periodic measurement of serum magnesium levels, should be performed. In patients with cardiac dysfunction, bradycardia may occur and symptoms may worsen.

3. Interactions With Other Drugs

Because Magumit has adsorption, antacid, and other effects, it may affect the absorption and excretion of other drugs. For example, when Magumit is used in combination with new quinolines or tetracyclines, the antibacterial effect is diminished, so it is necessary to allow at least two hours between doses.

In addition, when combined with large amounts of milk or calcium products, the calcium concentration in the blood may increase, causing the blood to become alkaline, so care should be taken while taking these medications and periodic blood tests are necessary.

What Is Furaneol?

Furaneol is a white to yellow crystal or powder.

The name Furaneol is a trademark of Firmenich AG, and the IUPAC name is 4-hydroxy-2,5-dimethylfuran-3-one. It is also known as 2,5-dimethyl-4-hydroxy-3(2H)-furanone, 4-Hydroxy-2,5-dimethyl-3(2H)-furanone, Strawberry furanone, Alletone, Pineapple ketone, and Dimethylhydroxy furanone.

It is an organic compound with the chemical formula C6H8O3 and molecular weight of 128.13. Its CAS number is 3658-77-3.

Uses of Furaneol

As its alias of strawberry furanone suggests, this compound has a strawberry-like aroma. Industrially, it is used as a food flavoring and perfume ingredient with a strawberry-like aroma.

It is used in diluted form because it becomes malodorous at high concentrations, and at a concentration of 0.01% it has a sweet, slightly burnt caramel, cotton candy-like savory aroma. The aroma threshold is so low that even 0.00004 mg or 0.00001 to 0.000005 mg in 1 kg of water can be perceived; at concentrations of 0.10 to 1.00 ppm, it has a sweet caramel or fruity taste.

It is found naturally in many fruits, including strawberries and pineapples, and is also an important aromatic component of buckwheat and tomatoes.

Properties of Furaneol

It is solid at room temperature, with a melting point of 77-79 °C and a boiling point of 216 °C. It is soluble in ethanol. It is soluble in ethanol and slightly soluble in water, chloroform and methanol.

The acid dissociation constant (pKa) is 8.56. The acid dissociation constant is a quantitative measure of the strength of an acid; a smaller pKa indicates a stronger acid.

Types of Furaneol

Furaneol has two enantiomers: (R)-(+)-Furaneol and (S)-(-)-Furaneol. The aroma of strawberry is attributed to the (R)-body.

Other Information on Furaneol

1. How Furaneol Is Produced

It is one of the products of glucose dehydration. It is biosynthesized from glucoside obtained by the dehydration of sucrose.

Industrially, 2,5-hexindiol is synthesized by ethynylation of acetaldehyde. 2,5-Hexindiol is then reacted with ozone and converted to hexane-2,5-diol-3,4-dione by reductive treatment.

Furaneol can then be synthesized by cyclization in the presence of an acidic catalyst. Alternatively, it can be produced from rhamnose in a multi-step bioprocess. 

2. Handling and Storage Precautions

When Handling
Avoid contact with oxidizing agents, which are hazardous intermingling materials. Handling should be done in a well-ventilated area or where local exhaust ventilation is available.

Wear appropriate protective equipment when using. Care should be taken to avoid the dispersal of dust.

In Case of Fire
Furaneol is flammable in its liquid state. Decomposition may produce carbon dioxide and carbon monoxide. Use water spray, foam, powder extinguisher, or carbon dioxide to extinguish fire.

In Case of Skin Contact
Be careful not to get it on skin. Protective clothing, such as lab coats or work clothes and protective gloves, must be worn when using the product. Never roll up the sleeves of protective clothing to avoid skin exposure.

In the event of skin contact, immediately rinse with water. If on clothing, remove and isolate all contaminated clothing. If skin irritation or rash develops, seek medical advice and treatment.

In Case of Eye Contact
Always wear protective eyewear or goggles when using the product. In case of eye contact, rinse cautiously with water for several minutes. If wearing contacts, remove them if they can be easily removed and rinse thoroughly. If eye irritation persists, seek medical advice and attention.

Storage
When storing, fill the container with inert gas such as nitrogen or argon gas, seal the container tightly, and store in a refrigerator (2-8°C). Store in a cool, well-ventilated place away from direct sunlight. It is also important to keep the product away from oxidizers and other incompatible hazardous substances.

What Is Phenethylamine?

Phenethylamine is an organic compound with C6H5(CH2)2NH2 and C8H11N.

It is an alkaloidal monoamine with the IUPAC nomenclature 2-phenylethanamine and other names such as β-phenylethylamine and 2-phenethylamine.

The CAS registration number is 64-04-0. Although the names are very similar, it should be noted that 1-phenylethylamine (also known as α-phenylethylamine, CAS No. 98-84-0) is a different compound.

Uses of Phenethylamine

The main use of phenethylamine is as a flavoring agent. It is registered as a food additive. In Europe and the United States, phenethylamine is used in processed foods, especially in baked goods, gelatin/puddings, meat products, soft candies, frozen dairy products, soft drinks, etc. Phenethylamine is also used as a flavor enhancer in various processed foods.

Phenethylamine is also believed to function as a neuromodifier and neurotransmitter in the human brain. Because of their structural similarity to monoamine neurotransmitters, many of their derivatives, substituted phenethylamines, are known to possess pharmacological activity.

For this reason, a group of derivatives of phenethylamine are used as drugs and medicines or as intermediate raw materials for pharmaceuticals. Phenethylamine derivatives with pharmacological activity include hypoallergenics, bronchodilators, and antidepressants in pharmaceuticals, and stimulants, hallucinogens, and empathogens in illicit drugs.

Characteristics of Phenethylamine

Phenethylamine has a molecular weight of 121.18, a melting point of -60°C, and a boiling point of 198°C. It is a clear colorless to yellowish brown liquid at room temperature. It has a fishlike odor, a pH of 11.5 (4.3 g/L, 20°C), and a density of 0.962 g/mL (20°C).

It is extremely soluble in ethanol, diethyl ether, and acetone, and soluble in water. It has a flash point of 90°C (tag sealed) and should be treated as a highly flammable liquid and vapor.

It is also known to react with carbon dioxide (CO2) to form carbonates when exposed to air.

Types of Phenethylamine

Phenethylamine is typically sold as a reagent product for R&D/pilot studies. The types of volumes include 25mL, 50mL, 100mL, and 500mL. This reagent product can be stored at room temperature due to its stable compounds.

Since hydrochloride is a solid, hydrochloride salt is sometimes used for ease of handling. This chemical is also commonly sold as a reagent product.

Other Information on Phenethylamine

Derivatives of Phenethylamine

Various compounds with chemical modifications in the phenyl group, side chain, and amino group are known as phenethylamine derivatives. For example, amphetamine, a drug with indirect adrenergic receptor stimulating effects (clinically applicable in the United States and other countries, but not in Japan), is a derivative with a α-methyl group adjacent to the amino group on the side chain.

Methamphetamine, widely used in Japan for drug abuse, is a derivative of amphetamine with a methyl group substituted on the nitrogen atom. Phenethylamine derivatives with hydroxy groups on the third and fourth positions of the phenyl group are classified as catecholamines, and include the transdermal substances levodopa, dopamine, noradrenaline, and adrenaline.

The aromatic amino acids of phenylalanine and tyrosine are also phenethylamine derivatives with a carboxyl group at the α-position.

What Is Phenylboronic Acid?

Phenylboronic acid is an organoboron compound.

It has the molecular formula C6H7BO2 and consists of a boron atom bonded to two hydroxy groups and one phenyl group. The phenyl group (C6H5-) is sometimes abbreviated to Ph and written as PhB(OH)2. It is also known as phenylboric acid and benzeneboric acid, and its CAS number is 98-80-6.

It has a molecular weight of 121.93, a melting point of 216°C, and is a white or yellow, odorless crystal or powder at room temperature. It is characterized by its solubility in polar organic solvents. On the other hand, it is virtually insoluble in non-polar solvents such as hexane and carbon tetrachloride. Phenylboronic Acid is a weak Lewis acid with an acid dissociation constant pKa of 8.83.

Uses of Phenylboronic Acid

Phenylboronic acid is used in various organic syntheses, taking advantage of its properties and reactivity as a weak Lewis acid. Examples of typical reactions include the Suzuki-Miyaura coupling reaction for the synthesis of biaryl compounds and palladium-catalyzed direct arylation.

Other compounds are used for their reactivity to make sensors and receptors for hydrocarbons and N-type polymers for all-polymer solar cells. Medical applications include antibiotics, enzyme inhibitors, and neutron capture therapy.

In biochemistry and chemical biology, the substance can also be used in biological reactions such as membrane permeation transport, bio-conjugation reactions, and protein labeling.

Characteristics of Phenylboronic Acid

The boron atoms of phenylboronic acid have empty p orbitals due to sp2 hybridization, and the molecular structure is a planar molecule with C2v molecular symmetry. This planar molecule is hydrogen bonded in bimolecular units with a slight bend across the C-B bond, and the angles formed by the planes of the two PhB (OH) bimolecules are 6.6° and 21.4°, respectively.

These dimeric units form hydrogen bonds with each other to form a rectangular molecular crystal system.

Types of Phenylboronic Acid

Phenylboronic acid is sold primarily as a reagent for research and development. The types of volumes include 1 g, 10 g, 25 g, 50 g, 100 g, and 500 g. It is a reagent product that can be stored at room temperature.

Phenylboronic acid anhydride may be included as an impurity.

Other Information on Phenylboronic Acid

1. Method of Synthesis of Phenylboronic Acid

There are many methods for synthesizing phenylboronic acid. The following is a list of some of the most representative ones.

• Reaction of phenylmagnesium bromide (Grignard reagent) with trimethyl borate to form the ester (PhB(OMe)2) and hydrolysis
• Trapping of electrophilic borates onto phenyl halides or phenyl-metal intermediates synthesized by orthometallation
• Transmetallation of phenylsilanes or phenylstannanes with BBr3 and hydrolysis of the products to obtain phenylborates
• Transition metal-catalyzed bonding of aryl halides and trifluoromethanesulfonates with diboronyl reagents
• Method of synthesis by transition metal-catalyzed C-H activation of aromatics

2. Chemical Reaction of Phenylboronic Acid

Phenylboronic acid is dehydrated to form the trimeric anhydride, boroxyn. This dehydration reaction proceeds thermally, and in some cases, a drying agent is added.

The compound is also useful as a reactant in cross-coupling reactions. A typical example is the Suzuki-Miyaura coupling, in which aryl halides react with phenylboronic acid in the presence of a palladium catalyst and base to produce biaryls.

α-Amino acids can be synthesized without the use of a catalyst by reacting α-keto acids, amines, and phenylboronic acid. There are also reports of Heck’s reactions using phenylboronic acid and alkenes or alkynes.

What Is Phenylacetaldehyde?

Phenylacetaldehyde is a compound with a structure in which one of the alpha-hydrogens of acetaldehyde is replaced by a phenyl group.

Many species of insects use this phenylacetaldehyde as a communicator. It is usually present as a colorless liquid and is characterized by its strong hyacinth-like floral fragrance.

Uses of Phenylacetaldehyde

Phenylacetaldehyde is mainly used as a flavoring agent in the preparation of flowers and fruits.

Phenylacetaldehyde by itself is described as having a honey-like, sweet, rose-like, fresh, and grassy aroma. It is used to enhance the aroma of tobacco as well as being used as a raw material for the preparation of fragrances such as hyacinth, narcissus, acacia, and cyclamen, and flavors such as raspberry, apricot, cherry, and spice.

What Is Phenylacetylene?

Phenylacetylene is an organic compound with the molecular formula C8H6.

Phenylacetylene consists of a phenyl group bonded to an alkyne. It is also known as ethynylbenzene, phenylacetylide, phenylethyne, 1-phenylethyne, etc. Its CAS number is 536-74-3. CAS registration number is 536-74-3.

It has a molecular weight of 102.133, a melting point of -44.8°C, and a boiling point of 143°C. At room temperature, it is a colorless or pale yellow, clear, highly viscous liquid. It is extremely soluble in ethanol, acetone, and diethyl ether, but almost insoluble in water. Its density is 0.93 g/cm3. 

Uses of Phenylacetylene

Phenylacetylene is mainly used as a raw material for organic synthesis. A typical example of a reaction is the formation of polyphenylacetylene through a polymerization reaction. This reaction proceeds using Rh and Pt complexes and tungsten as catalysts.

It is also used in the conversion of nitrones to alkynylhydroxylamines in the presence of trimethylaluminum. It is also often used in research as an analog of acetylene.

This is because liquid phenylacetylene is easier to handle than gaseous acetylene. Examples of organic reaction chemistry studies include the reported oxidative carbonylation of phenylacetylene in the presence of palladium catalysts.

Properties of Phenylacetylene

1. Synthesis of Phenylacetylene

Phenylacetylene can be synthesized by the reaction of β-bromostyrene with molten potassium hydroxide to remove hydrogen bromide or with sodium amide in ammonia as a base to remove hydrogen bromide from styrene dibromide.

2. Chemical Reaction of Phenylacetylene

Phenylacetylene can be partially hydrogenated using a Lindler catalyst (palladium catalyst supported on calcium carbonate). This reaction yields styrene. Phenylacetylene can also be cyclotrimerized with cobalt (II) bromide to yield 1,2,4-triphenylbenzene (97%) and 1,3,5-triphenylbenzene.

Like acetylene, phenylacetylene reacts with ammoniacal copper and silver salt solutions to form explosive metal salts.

3. Safety Control Information for Phenylacetylene

Phenylacetylene may be altered by light. It has a low flash point of 31°C. It should be stored away from high temperatures, direct sunlight, heat, sparks, and static electricity. Miscibility with strong oxidizers is considered dangerous, and carbon monoxide and carbon dioxide are listed as hazardous decomposition products.

Types of Phenylacetylene

Phenylacetylene is sold mainly as a reagent product for development and research.

The products are available in different volumes such as 25g , 25mL, 100mL, and 500mL, and are offered in volumes that are easy to handle in the laboratory. These reagent products require refrigerated storage. Phenylacetylene has a low flash point of 31°C and is designated as a hazardous material. 

What Is Trigonelline?

Trigonelline is a colorless solid. Its IUPAC name is 1-methylpyridin-1-ium-3-carboxylate, and it is also known as caffearine or N-methylnicotinate. Methylnicotinate.

It is an alkaloid, an organic compound containing nitrogen atoms with the chemical formula C7H7NO2 and a molecular weight of 137.14. The CAS registration number is 535-83-1.

Uses of Trigonelline

Trigonelline has a variety of effects, including antidiabetic, antioxidant, anti-inflammatory, and neuroprotective effects. Fenugreek, a plant with trigonelline as one of its main constituents, is a traditional Chinese herb and Indian spice that has long been used for diabetes, coughs, increased milk production, and anti-inflammatory effects.

Today, it is attracting attention as a highly effective substance for improving dementia and Alzheimer’s disease. In addition, by generating nitric oxide in blood vessels, it can promote vasoconstriction and dilation to maintain supple blood vessels. It is also attracting attention as a substance that prevents myocardial infarction and cerebral infarction caused by arteriosclerosis.

Properties of Trigonelline

Trigonelline is heat sensitive and decomposes at temperatures above 200°C. In order to maintain the function of Trigonelline, it must be heated below 200°C, or Trigonelline must be extracted before heating and returned after heating.

Upon heating, trigonelline is converted to nicotinic acid. This substance is different in type from the nicotine found in cigarettes and has the effect of promoting brain energy metabolism and reducing cholesterol.

Nicotinic acid is a form of vitamin B3, which helps replace carbohydrates and fats with energy. Trigonene has a betaine structure with both positive and negative charges in a molecule.

The melting point of the monohydrate is 218°C, and it decomposes upon melting. It is solid at room temperature. It is very soluble in water, soluble in alcohols, and almost insoluble in organic solvents such as ether, benzene, and chloroform.

Other Information on Trigonelline

1. How Trigonelline Is Produced

Trigonelline is found in abundance in the seeds of the osmanthus and coffee beans. It was first isolated from the leguminous plant fenugreek.

In plants, it is biosynthesized from nicotinic acid by nicotinic acid-N-methyltransferase (EC No. 2.1.1.7). Industrially, it can be synthesized by heating nicotinic acid with methyl iodide in the presence of silver oxide.

Trigonelline can also be purified by recrystallization from water or alcohols. 

2. Handling and Storage Precautions

Trigonelline produces harmful nitrogen oxide (NOx) vapors when heated to decomposition. It is important to use the product in a draft chamber with local exhaust ventilation to avoid direct inhalation of the vapors. In case of fire, use water spray, dry chemical, foam, or carbon dioxide fire extinguishers.

Because of its skin irritant properties, care should be taken to avoid skin contact. Always wear protective clothing, such as a lab coat or work clothes and protective gloves when using the product. Never roll up the sleeves of protective clothing to avoid skin exposure. In the unlikely event of skin contact, it is important to wash it off with soap and copious amounts of water. If pain or other symptoms persist, seek medical attention.

It is also highly irritating to the eyes. It is important to always wear protective eyewear or goggles when using this product, as it can cause serious damage. In the unlikely event of contact with the eyes, rinse carefully with water for several minutes. If you are wearing contacts and can easily remove them, do so and rinse thoroughly.

Store in a cool, well-ventilated place away from direct sunlight, around 4°C is preferable.

What Is Triethylamine Hydrochloride?

Triethylamine hydrochloride is a salt (ammonium salt) formed when triethylamine, a strongly basic organic amine (tertiary amine), is reacted with hydrochloric acid.

The original triethylamine is a liquid that mixes with organic solvents, while the hydrochloride salt is a solid that is highly water soluble. Also known as triethylammonium chloride, its chemical formula is (C2H5)3N – HCl and its CAS number is 554-68-7.

It is usually present as a white solid and is characterized by a slight amine odor.

Uses of Triethylamine Hydrochloride

Triethylamine hydrochloride is mainly used as a raw material for organic synthesis of pharmaceuticals and dyes. For example, triethylamine is liberated using a strong base, which is then reacted with other molecules. It is also used as an ion-pair reagent in ion-pair extraction, in which an aggregate is formed with an acidic substance and extracted into an organic solvent (ion-pair extraction), because it has three hydrophobic ethyl groups and is a strong base.

As in extraction, it can also be used in ion-pair high-performance liquid chromatography (HPLC). As in extraction, ion-pair reagents are used to form ion pairs by associating with acidic substances to allow analysis of water-soluble acidic substances by reversed-phase HPLC. However, tetraethylammonium hydrochloride, a quaternary ammonium salt that is more effective in HPLC, is increasingly being used.

In liquid chromatography-mass spectrometry (LC-MS), where volatility is important, more volatile reagents, such as triethylamine acetate are sometimes used. Triethylamine Hydrochloride is relatively inexpensive compared to these ion-pair reagents. It is also used as a comparison reagent for sodium chloride in biochemical experiments to study the effects of sodium ions because of its weakly acidic to neutral liquid properties.

Properties of Triethylamine Hydrochloride

Triethylamine hydrochloride is a white solid (crystalline or crystalline powder). It is soluble in water and ethanol, but not in ether. It is particularly soluble in water.

Aqueous solutions range from near neutral to slightly acidic, with a pH of 3.0-6.0 at a concentration of 50 g/L. Its melting point is not considered definite, and it decomposes at about 260°C when heated.

The powder is tidally soluble, so care should be taken with humidity when storing and handling. In addition, light shielding is essential when storing the product, as it may be altered by light.

Other Information on Triethylamine Hydrochloride

1. Manufacturing Process of Triethylamine Hydrochloride

Triethylamine Hydrochloride is produced by chemical synthesis. It is generally synthesized by alkylating ammonia with ethanol to obtain triethylamine, which is then converted to hydrochloride. 

2. Applicable Laws and Regulations for Triethylamine Hydrochloride

It is known to be corrosive and irritating to skin, severely damaging to eyes, and irritating to eyes. 

However, as a general precaution for chemical substances, dust-protective masks and protective gloves should be worn and the product should be handled in an environment with local exhaust ventilation. It is also important to avoid mixing with strong oxidizers, as they react violently.

In the event of a fire, complete combustion produces carbon dioxide and nitrogen oxides, and simultaneously hydrogen chloride gas. Thermal decomposition may also generate amine and ammonia, both of which are harmful to the human body.

Triethylamine hydrochloride may produce triethylamine. Because triethylamine is harmful to the aquatic environment, disposal of triethylamine hydrochloride must also be conducted in such a way that there is no environmental release.

What Is Hydrogen Selenide?

Hydrogen selenide is a compound of selenium and hydrogen.

Its chemical formula is represented by H2Se. It is normally found as a colorless gas with a garlic-like odor and toxic properties similar to hydrogen sulfide. In aqueous solution (hydro selenide acid), it easily ionizes into selenide ion (Se2-) and hydrogen ion. Therefore, it is acidic.

Uses of Hydrogen Selenide

Hydrogen selenide is obtained by reacting selenium with aluminum powder using a magnesium ribbon fire to form aluminum selenide, followed by a drop of water in a nitrogen stream.

It is mainly used in the synthesis of organoselenium compounds. Organoselenium compounds include selenol, selenide, and diselenide, which are also used as synthetic raw materials for other compounds. They are also used to add small amounts of selenium to semiconductors (doping).

Properties of Hydrogen Selenide

Hydrogen selenide is similar to hydrogen sulfide in the following ways. This is probably due to the fact that selenium and sulfur are members of the same group 16 element (chalcogen). Hydrogen selenide and hydrogen sulfide both have similar properties as hydrogen compounds of chalcogen.

1. Low Boiling Point

Hydrogen selenide has a boiling point of -41.25°C. The boiling point of hydrogen sulfide is -60°C, which is close, but the boiling point of water (H2O), a hydrogen compound of the same chalcogen as selenium and sulfur, is 100°C, which is very high.

Because liquid water is strongly bonded to water molecules by hydrogen bonds, high energy is required to break these bonds and vaporize it. Water molecules are polar molecules, which means that there is an electrical bias within the molecule. Thus, slightly positively charged hydrogen in one water molecule is electrically attracted to slightly negatively charged oxygen in a nearby water molecule.

Hydrogen selenide and hydrogen sulfide are also polar molecules, but their polarity is smaller because the electronegativity of selenium and sulfur is only slightly greater than that of hydrogen. Therefore, hydrogen bonds are weak and the boiling point is low as a result.

2. Pungent Odor

Hydrogen selenide has a strong garlic-like odor, which irritates the mucous membranes of the nose and respiratory tract when inhaled. Hydrogen sulfide also has a pungent odor that is described as “rotten egg smell.”

3. When Dissolved in Water, It Exhibits Acidity.

When hydrogen selenide is dissolved in water, it ionizes into selenide ion (Se2-) and hydrogen ion. It is, therefore, acidic. Hydrogen sulfide, when dissolved in water, also ionizes into hydrogen sulfide ion (HS-) and sulfide ion (S2-) and hydrogen ion, resulting in acidity.

4. Easily Flammable

Hydrogen selenide is highly flammable and forms water and selenium dioxide when it burns. Hydrogen sulfide burns to form water and sulfur dioxide. Selenium dioxide is solid at room temperature, while sulfur dioxide is a gas at room temperature.

Structure of Hydrogen Selenide

Hydrogen selenide has a folded molecular structure with a bond angle of about 91° between the two hydrogen atoms. Because of this structure, it is slightly polar.

Other Information About Hydrogen Selenide

1. Production of Hydrogen Selenide

When water is added to aluminum selenide, it is formed together with aluminum oxide. When hydrochloric acid is added to aluminum selenide, it is formed together with aluminum chloride.

In addition to the method of producing hydrogen selenide from selenium and metal compounds, hydrogen selenide can also be produced by the direct reaction of selenium alone with hydrogen.

2. Safety Information on Hydrogen Selenide

Hydrogen selenide is designated as a hazardous substance and flammable gas. 

Hydrogen selenide is designated as a special high-pressure gas. Other designated special high-pressure gases include arsine, disilane, diborane, phosphine, monogermanes, and monosilane, all of which are flammable, toxic, and dangerous gases.

Contact with water, alkalis, oxidizers, or halogenated hydrocarbons can cause fire or explosion. When in contact with air, there is a risk of forming explosive gas mixtures.