The aldehydes are compounds with carbonyl group (C = O) at the end of the chain, i.e the carbonyl is primary.
Content Index :
- 1 Properties
- 2 Importance: some important aldehydes
- 2.1 Methanal (Formaldehyde)
- 2.2 Ethanol (Acetaldehyde)
- 2.3 Propane (Propionaldehyde)
- 2.4 Butanal (Butiraldehyde)
- 2.5 Pentanal (Valeraldehyde)
- 2.6 Phenylmethane (Benzaldehyde)
- 2.7 Vanillin
- 3 Curiosities
Properties of aldehydes
The smell of low molecular mass aldehydes is irritating , but as the number of carbons increases it becomes more pleasant.
They come in gaseous, liquid or solid form and the aldehydes of the small chains are soluble in water due to the hydrogen bonds they form, gaining apolarity as the carbon chain increases.
An interesting fact about aldehydes is that their molecules do not bond with each other by hydrogen bonds , but are attracted by permanent dipole forces.
Importance: some important aldehydes
Known as formol or formic aldehyde, with structural formula CH2O, it is used in the manufacture of disinfectants and plastics.
In addition, it is important in the development of scientific studies, since it serves to preserve the corpses (embalming fluid).
Acetic aldehyde, with molecular formula C2H4O, is used in the production of ethanol, acetic acid, in the manufacture of mirrors, medications, synthetic resins, pesticides, dyes and also in fruit preservation.
Propionic aldehyde, with molecular formula C3H6O, is used in the production of drugs, flavors, propionic acid, plastics, disinfectants, among others.
Butyraldehyde, with molecular formula C4H8O, is used in the production of resins, plasticizers, accelerators, as well as in the manufacture of synthetic aromas.
The valeric aldehyde, with molecular formula C5H10O, is used in the production of flavors, resins and vulcanization accelerators.
Benzoic aldehyde, with molecular formula C7H6O, is used in the synthesis of organic compounds, in the production of dyes, perfumes and cosmetics.
Phenolic aldehyde, with molecular formula C8H8O3, is the main component of vanilla seed and, therefore, is used in the production of artificial flavors in the food and pharmaceutical industries.
The acetaldehyde (ethanal) is one of those responsible for the “hangover”, ie, the discomfort that occurs following excessive ingestion of alcoholic beverages, since it is metabolized by dehydrogenase enzyme present in the liver.
As for the odors of aldehydes, it is worth mentioning that compounds that have a greater number of carbon atoms are usually characterized by a pleasant and fruity smell ; on the other hand, aldehydes that have a lower number of carbon atoms have a more irritating and strong smell.
Thus, the aldehydes used in the manufacture of perfumes have between 8 and 12 carbon atoms.