Carboxylic acid

A carboxylic acid is an organic compound that contains a carboxyl group (C(O)OH). The general formula of a carboxylic acid is R-C(O)OH with R referring to the rest of the (possibly quite large) molecule.

Quotes

• The dipolar Lewis structure indicates the polarization of the C=O bond. Even though it is a minor contributor (because of the lack of an octet on carbon), it explains the deshielding of the carbonyl carbon. In carboxylic acids, however, the corresponding dipolar form contributes less to the resonance hybrid: The hydroxy oxygen can donate an electron pair to give a third arrangement in which the carbon and both oxygen atoms have octets. The degree of positive charge on the carbonyl carbon and therefore its deshielding are greatly reduced. The changes in electron density distribution around the carbonyl function when going from acetone to acetic acid are shown in their respective electrostatic potential maps.
  • K. Peter C. Vollhardt, Neil E. Schore (2011) Organic chemistry : structure and function 6th ed. Ch. 19 : Carboxylic Acids

• Carboxylic acids are useful reagents and synthetic precursors. The two simplest ones are manufactured on a large scale industrially. Formic acid is employed in the tanning process in the manufacture of leather and in the preparation of latex rubber. It is synthesized effi ciently by the reaction of powdered sodium hydroxide with carbon monoxide under pres sure. This transformation proceeds by nucleophilic addition followed by protonation.
  • K. Peter C. Vollhardt, Neil E. Schore (2011) Organic chemistry : structure and function 6th ed. Ch. 19 : Carboxylic Acids

• Many of the oxidants employed to prepare aldehydes from primary alcohols may be used to further oxidize the aldehyde initially formed to the corresponding carboxylic acid. The most common oxidants for this purpose include KMnO₄, chromic acid, sodium chlorite, silver oxide, and PDC in DMF.
  • George S. Zweifel and Michael H. Nantz, Modern Organic Synthesis (2006), Ch. 4 : Functional Group Transformations: Oxidation and Reduction