2-Ethylhexanoic acid

2-Ethylhexanoic acid is the organic compound with the formula CH3(CH2)3CH(C2H5)CO2H. This carboxylic acid is widely used to prepare metal derivatives that are soluble in nonpolar organic solvents. These lipophilic metal-containing derivatives are used as catalysts in polymerizations. For example, tin 2-ethylhexanoate is used in the production of poly(lactic-co-glycolic acid). The high solubility of these metal complexes is attributable to the long hydrocarbon chain and the presence of a chiral center which leads to mixtures of diastereoisomeric complexes. These metal complexes are often described as salts, when in fact they are not ionic but charge-neutral coordination complexes akin to the better defined, more crystalline acetates.

Examples of metal ethylhexanoates

 * Hydroxyl aluminium bis(2-ethylhexanoate), used as a thickener.
 * Tin(II) ethylhexanoate (CAS# 301-10-0) as a catalyst for polylactide polymerization.
 * Cobalt(II) ethylhexanoate (CAS# 136-52-7) as a drier for alkyd resins.
 * Nickel(II) ethylhexanoate ((CAS# 4454-16-4)

Health aspects
Some studies showed now subchronic oral toxicity. but as a studiy indicated the teratogenicity of the compound the sources for exposure where evaluated. One major source are the metal derivatives of 2-ethylhexanoic acid, which are widely used as stabilizers for polyvinyl chloride PVC. The other source is the metabolism of bis(2-ethylhexyl) phthalate (DEHP) the two ester bonds are hydrolysed and the resulting 2-ethylhexanol is oxidized in the organism to 2-ethylhexanoic acid. The elevated levels of the compound in even glass jars was due to the diffusion of the compound from the PVC cap into the food.