ANT ALDEHYDE (synonym: formaldehyde, methanal) — the first representative of a class of aldehydes, HCHO, has antiseptic properties thanks to what its water 37 — 40% solution under the name formalin is widely applied to fixation of anatomic and microscopic drugs, at production of vaccines and serums, to disinfection and disinsection of rooms, clothes, ware, medical tools, a protravlivaniye of seeds, etc. At long contact represents considerable professional harm.
For the first time M. and. it was received in 1859 by A. M. Butlerov, and in 1868 Mr. Hofmann, having received M. and. oxidation methyl alcohol (see), established its structure.
M and. represents colorless gas with a pungent smell, a pier. the weight (weight) 30,03, its density at 20 ° t ° is equal 0,815, pl — 92 ° (according to other data — 118 °), t ° kip — 19,2 °. Let's well dissolve in water, alcohol, diethyl alcohol, it is insoluble in petroleum ether.
M and. — high-reactionary connection. It easily is oxidized in formic acid (see), being a strong reducer, emits many metals (copper, silver, platinum, etc.) from the corresponding salts. In pure form or solution it will easily be polymerized, forming a firm white product — paraformaldehyde. In water solutions M. and. undergoes polymerization on type aldol condensation (see) in uglevodopodobny connections. M and. vigorously interacts with nitrogenous compounds of the main character, napr, at action on M. and. or paraformaldehyde of ammonia is formed hexamethylenetetramine (see), earlier being called urotropin and widely used in medical practice as medicine. M and. easily reacts with NH 2 - groups, this its property is used in analytical and preparative reactions, and also in many commercial runs.
In M.'s industry and. receive catalytic oxidation of methyl alcohol.
Bibliography: Karrer P. A course of organic chemistry, the lane with it., page 200, JI., 1960; Pearce E. A histochemistry, the lane with English, page 207, 314, M., 1962; The Principles cyto - and the histochemical analysis, under the editorship of A. P. Avtsyn, etc., M. — L., 1971; Walker D. F. Formaldehyde, the lane with English, M., 195 7, bibliogr.
M. I. Rozengart.