Fosforesterer

Fosforesterer, or phosphate esters, are a class of chemical compounds formed by substituting one or more hydroxyl groups of phosphoric acid with alcohol groups. In general, triester phosphate esters have the structure P(=O)(OR)3, diesters have two OR substituents and one remaining hydroxyl, and monoesters have one OR substituent with two remaining hydroxyls. The R groups, which come from alcohols, can be alkyl, aryl, or more complex structures. Phosphoric acid esters are typically prepared by esterification of phosphoric acid or by reactions of phosphoryl halides with alcohols, often under dehydrating conditions.

Biological relevance is substantial. Phosphate esters are central to the chemistry of life: nucleic acids contain phosphodiester bonds that link sugar units, forming the backbone of DNA and RNA; adenosine triphosphate (ATP) and other nucleoside triphosphates are phosphate esters that store and transfer energy. Phosphorylation of proteins and other molecules, forming various phosphate esters, is a key mechanism in cellular signaling and regulation.

Industrial and consumer applications include organophosphate esters used as flame retardants, plasticizers, lubricants, hydraulic fluids, and additives in coatings and inks. Their properties vary with the identity of the alcohol-derived R groups, enabling a range of polarities and volatilities. Some phosphate esters are susceptible to hydrolysis, yielding phosphoric acid and alcohols, which influences their environmental fate and safety considerations.

Safety and environmental aspects depend on the specific compound. While many phosphate esters are relatively inert, certain organophosphate esters can be hazardous and require appropriate handling and disposal.