carboxyl group

chemistry

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June 26, 2026

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In organic chemistry, a carboxyl group is a functional group consisting of a carbon atom double-bonded to an oxygen atom and single-bonded to a hydroxyl group (–OH). This structure, represented as –COOH, is characteristic of carboxylic acids.12

The polarity of the carbonyl bond (C=O) within the carboxyl group, due to the difference in electronegativity between carbon and oxygen, makes molecules containing it polar. This polarity influences their solubility and boiling points compared to similar hydrocarbons. The hydrogen atom in the hydroxyl part of the carboxyl group is acidic and can be donated, making carboxylic acids weak acids. This acidity is enhanced by electron-withdrawing groups attached to the carbon atom. The carboxyl group is a key organizing feature in organic chemistry, allowing chemists to predict a molecule's reactivity.324

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chemical compound
Carboxylic acids
…functional group known as a carboxyl group.
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…functional group known as a carboxyl group.
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lipid
Chemical properties
…fatty acids is the acidic carboxyl group (COOH). It reacts with alcohols (R′OH) to form products known as esters (RCOOR′) and releases water in the process. This ester bond is the principal covalent bond linking fatty acid moieties to other groups in the more-complex lipids discussed in other sections of…
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…fatty acids is the acidic carboxyl group (COOH). It reacts with alcohols (R′OH) to form products known as esters (RCOOR′) and releases water in the process. This ester bond is the principal covalent bond linking fatty acid moieties to other groups in the more-complex lipids discussed in other sections of…
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spectroscopy
Analysis of absorption spectra
…example, all molecules containing a carboxyl group (C=O) will have a normal vibrational mode that involves the stretching of the carbon-oxygen double bond. Its particular frequency will vary, depending on the nature of the atoms or groups of atoms attached to the carbon atom but will generally occur in the…
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…example, all molecules containing a carboxyl group (C=O) will have a normal vibrational mode that involves the stretching of the carbon-oxygen double bond. Its particular frequency will vary, depending on the nature of the atoms or groups of atoms attached to the carbon atom but will generally occur in the…
Read More