compound having in its structure a carbonyl group are aldehydes or ketones.The aldehydes (RCOH) carbonyl group is bonded to a hydrocarbon radical and a hydrogen atom.We can say that these substances contain aldehyde (-COH), wherein the carbonyl center is connected with a hydrogen atom.The ketones (RCOR ') attached to a carbonyl group two hydrocarbon radicals.The name derives from the aldehyde acids, in which they are converted by oxidation, for example, ant (formaldehyde), ethyl (acetaldehyde), propionaldehyde, butyric, valeric aldehydes.According to international nomenclature called aldehydes: ethanal, propanal.The names of ketones formed from the name of the radicals, to which is added the ending ketone.For example, dimethyl ketone (acetone), methyl ethyl ketone.Title International Nomenclature ketones derived from the name of the hydrocarbon with the addition -one closure and the point of attachment of the carbonyl group indicates a number, for example 2-propanone, 2-butanone.Use of aldehydes and ketones, due to their physical and chemical properties.
aldehydes are common in organic chemistry.Many fragrances are connected with these substances.Aldehydes have properties that are varied and depend on the radical, which is part of the molecule.Lower representative - formic aldehyde - gas, follow - liquids, solids are higher.Formaldehyde and acetaldehyde are highly soluble in water, the solubility of other homologs decreases with increasing molecular weight.Formic acid and acetaldehyde have a pungent smell.Properties and use of aldehydes due to the presence in its molecule of the carbonyl group.
two lower members of this homologous series in the "use of aldehydes" are the most important value for the industry - it is formaldehyde and acetaldehyde.Formaldehyde is produced on a large scale of about 6 million. Tons / year.It is mainly used in the production of resins.Prepared by polycondensation of urea and urea resins required for the manufacture of wood and particleboard, urea-formaldehyde foam, for making wet strength paper or paperboard.Another important use of aldehydes is based on the polycondensation reaction of formaldehyde with phenol.Obtained by this process formaldehyde resin (Bakelite) is unsurpassed material which is demanded in mechanical engineering, in the manufacture of abrasive electrical products, in the production of lacquers and adhesives.Of the pharmaceutical preparations prepared formaldehyde (formaldehyde solution known as formalin, is used in medicine), synthetic rubber, explosives and many other organic substances.
Acetaldehyde was once the dominant product, but the volume of production decreased, now its release less than 1 mln. Tons / year.Previously it was customary use acetaldehyde as a raw material for acetic acid.This application acetaldehyde decreased in recent years, because acetic acid is produced more efficiently from methanol (Monsanto process and Cativa process).From the viewpoint of the condensation reaction, acetaldehyde is an important raw material for the pyridine derivatives of pentaerythritol and crotonaldehyde.Acetaldehyde is necessary for the production of plastics (urea and acetaldehyde obtained useful resin).
Other members of this homologous series are also in demand in the market.Commercial use of aldehydes is often they are used as raw materials for the synthesis of oxo alcohols used in the production of detergents.Some higher aldehydes are produced in small quantities (less than 1000 tons / year) and used as a flavor ingredients in perfumes.They include cinnamon and its derivatives, citral, lilial and.
