hydroxyl group
Noun: A hydroxyl group is the univalent chemical group -OH, consisting of one oxygen atom bonded to one hydrogen atom. It is a fundamental functional group found in many classes of organic and inorganic compounds, including alcohols, carboxylic acids, and bases.
The term "hydroxyl group" is used specifically to refer to the -OH unit itself within a molecule. It describes the group's structure and its role in determining a compound's chemical properties and reactivity. * The presence of a hydroxyl group is what defines an alcohol. * This molecule contains a carboxylic acid, identifiable by its carboxyl group, which includes a hydroxyl group. * The reactivity of the compound is primarily due to its hydroxyl group.
- In methanol (CH₃OH), the hydroxyl group is attached to a methyl group.
- The hydroxyl group in water (H-OH) makes it an excellent solvent for many ionic compounds.
- Sugars like glucose have multiple hydroxyl groups, which contribute to their solubility in water.
- Hydroxyl Radical: This is a distinct, highly reactive species (·OH) with an unpaired electron. It is not a "hydroxyl group" in the standard sense, as it is a free radical, not a stable part of a bonded molecular structure.
- The acidity or basicity of a compound can be influenced by the electronic environment surrounding the hydroxyl group.
- Hydroxy-: A prefix used in chemical nomenclature to indicate the presence of a hydroxyl group, e.g., .
- Hydroxide: Refers to the anion OH⁻ or ionic compounds containing it (e.g., sodium hydroxide, NaOH). This is related to, but distinct from, the covalent hydroxyl group.
- Alcohol: A class of organic compounds characterized by one or more hydroxyl groups attached to a saturated carbon atom.
- -OH group
- Hydroxy group (less common variant)
The hydroxyl group is a specific functional group. It should not be confused with: 1. The hydroxide ion (OH⁻), which is a negatively charged ion. 2. The hydroxyl radical (·OH), which is a neutral, highly reactive free radical. The key distinction is that a "hydroxyl group" is covalently bonded within a larger molecule.
- the monovalent group -OH in such compounds as bases and some acids and alcohols