carboxylcontaining

Carboxyl-containing is a descriptive term used in chemistry to refer to molecules that include at least one carboxyl group, typically the carboxyl functional group -COOH, or its deprotonated form -COO-. In many contexts, related functional groups such as esters, amides, anhydrides, and carboxylates are also considered carboxyl-containing because they retain the carbonyl carbon and related oxygen substituents of the carboxyl group, even though they may lack the acidic OH.

The carboxyl group features a carbonyl bound to a hydroxyl group; the group is highly polar, capable of hydrogen bonding, and the acids are weak, with pKa values commonly around 4–5 for aliphatic carboxylic acids. In water, they can donate a proton to form carboxylate anions, influencing solubility and reactivity. Common examples include formic, acetic, and propionic acids; oxalic and citric acids are polycarboxylates. Carboxyl-containing compounds are central in biology (amino acids, fatty acids, citric acid cycle intermediates), industry (polyesters, detergents, food additives), and materials science (polyacrylic acids, chelating agents).

Analytical notes: infrared spectroscopy shows a sharp C=O stretch near 1700 cm-1 and a broad O–H stretch for acids, while esters show a C=O band around 1735–1750 cm-1 with no broad OH. Synthesis commonly involves oxidation of alcohols or aldehydes, or hydrolysis of esters and nitriles.