dihydric alcohol
Học thuậtThân thiện
Definition
- Noun:
- Any of a class of alcohols having 2 hydroxyl groups in each molecule: A "dihydric alcohol" is a specific type of organic compound in chemistry. It is an alcohol, meaning it contains one or more hydroxyl (-OH) groups attached to a carbon atom. The prefix "di-" indicates two, and "hydric" relates to hydrogen or hydroxyl groups. Therefore, a dihydric alcohol is characterized by having exactly two hydroxyl (-OH) groups in its molecular structure.
Usage Examples
- Noun:
- Ethylene glycol, a common antifreeze, is a well-known dihydric alcohol.
- The chemical formula of a simple dihydric alcohol like 1,2-ethanediol is C₂H₆O₂.
- In organic synthesis, a dihydric alcohol can serve as a starting material for polymers.
Advanced Usage
- Chemical Nomenclature: In systematic IUPAC naming, dihydric alcohols are often called "diols." The simplest and most industrially significant dihydric alcohol is ethylene glycol (IUPAC name: ethane-1,2-diol).
- Glycerol is not a dihydric alcohol; it is a trihydric alcohol (triol) because it contains three hydroxyl groups.
Variants and Related Words
- Diol (n): A synonym for dihydric alcohol in chemical terminology.
- Propylene glycol is a diol used in food and pharmaceutical products.
- Glycol (n): A common term often used interchangeably with dihydric alcohol, especially for vicinal diols (where the two -OH groups are on adjacent carbon atoms).
- Ethylene glycol is sometimes simply referred to as 'glycol.'
- Polyol (n): A more general term for alcohols containing multiple hydroxyl groups, which includes dihydric, trihydric, and other polyhydric alcohols.
Synonyms
- Diol: The standard synonym in organic chemistry.
- Glycol: Commonly used for specific, especially vicinal, dihydric alcohols.
Notes on Meaning
- The term "dihydric alcohol" is precise and technical. It refers specifically to the molecular structure (two -OH groups) and not to common properties like being a beverage. These compounds are typically viscous, sweet-tasting liquids used as antifreeze agents, humectants, or chemical intermediates.
Noun
- any of a class of alcohols having 2 hydroxyl groups in each molecule