CARBOXYLIC ACIDS — a class of the organic compounds containing carboxyl (COOH —) group. To. to. play an important role in the course of a metabolism at animals and the person, participating in a cycle of di - and Tricarboxylic to - t (see. Tricarboxylic acids cycle ). Some To. to. are biogenic stimulators (see). Many To. to. find application in medicine and the national economy: salts lemon and oxalic to - t (citrates and oxalates) apply to prevention of a blood coagulation; ant, acetic, lemon and the benzoic to - you use in the food industry at conservation. Lead salts fat to - t (lead plasters) are also used in medicine. Potassium and sodium salts of the highest fat to - t are soaps etc. Depending on number of COOH-group To. to. divide into mono - di - and polycarboxylic to - you. To. to., the containing double and acetylene bonds, call nonlimiting carboxylic to-tami.
To. to. are eurysynusic in the nature in a free look, and also are available: lemon to - that is in lemons, amber — in amber, the highest fat to - you in the form of ethers of glycerin — in fats * plant and animal origin, the benzoic to - that is in many balms, cowberry and so forth. Derivative the benzoic to - you and glycine — benzaminoacetic to - that contains in urine of animals; in an organism of birds the benzoic to - that contacts ornithine with education orniturovy to - you. Majority K.k. has the generic names indicating a source from to-rogo they were for the first time allocated: ant to - that is from ants, acetic — from grape vinegar etc. According to the Geneva nomenclature of the name K. to. form from the name of hydrocarbons with the same number of carbon atoms, as in to - those, adding the termination «ovy» and the word «acid». E.g., ant to - that is called metane, oxalic — etandiovy etc.
The lowest aliphatic To. to. (ant, acetic, etc.) — the liquids with a pungent smell which are mixing up with water in any relations; averages To. to. with number of carbon atoms from 5 to 9 represent oils, poorly water soluble; the highest To. to. (olein, stearin, etc.) — crystal substances, water-insoluble, but well soluble in organic solvents. Limit dicarbonic to - you and aromatic To. to. — solid matters, water soluble.
In comparison with mineral to-tami To. to. are weak to-tami. Nonlimiting and aromatic To. to., as a rule, stronger to - you, than limit To. to., with the same number of carbon atoms. Dicarbonic to - you are stronger, than monocarboxylic with the same number of carbon atoms, their acidity of subjects is more, than the chain of the carbon atoms connecting COOH groups is shorter. To. to. give numerous derivatives: salts, amides, ethers, anhydrides etc.
Separate carboxylic to - you — see articles according to the name to - t (e.g., Valerianic acids , Glyoxylic acid , Fatty acids , Caproic acid , Malonic acid , Lactic acid , Formic acid , Acetic acid ).
Bibliography: Nesmeyanov A. N. and Nesmeyanov N. A. Beginnings of organic chemistry, book 1 — 2, M., 1974; Stepanenko B. N. Course of organic chemistry, page 206, M., 1974.
N. B. Kozlova.