Amine salts are similar to ammonium salts where the hydrogen atoms attached to the nitrogen are replaced by organic groups. Amines react with acids to form salts, which are named as substituted derivatives of ammonium compounds. For example, dimethylamine reacts with hydrogen chloride to form dimethyl ammonium chloride, which is an ionic compound. Amine salts formed from amines are crystalline materials that are readily soluble in water. Many insoluble alkaloids (such as quinine and atropine) are used in the form of a pharmaceutically acceptable soluble salt (hydrochloride).
Material chemistry: The combination of anionic Co(III) complex and amine salts can be used as the precursor of the Co3O4 thin films, whose properties can be controlled by N-alkyl chains. The length of the alkyl group in the complex may affect the affinity of the precursory film to the glass substrate, and the introduction of long alkyl groups on the amine is sufficient to prevent the compound from crystallizing on the substrate. The ammonium salt is separated as a single crystal from the aqueous solution.
Organic chemistry: It has been reported that an intramolecular oxygen-Michael reaction can be catalyzed by a cheap and easily prepared chiral primary amine salt. Mild reaction conditions are more compatible with the functional groups or protecting groups of the substrate, and potential side reactions can be avoided, which may expand its application range in total synthesis. The diastereoselective synthesis of tetracyclic compounds with strong structural rigidity starting from the same chiral molecule is achieved. When the temperature rises to 50°C, diastereomeric tandem Michael-Michael reaction products can be obtained. This result is particularly noteworthy because it provides a compact and stereoselective access to complex tetracyclic compounds with multiple chiral centers, which can be used for the total synthesis of complex natural products.
Industry use: Amine salts have bactericidal and anti-mildew properties. Quaternary amine salts are used as fabric softener that can soften fiber surface. Octadecyldimethylammonium bromide is not only bactericide but also has a significant softening effect on cotton, wool and fabrics. Quaternary amine salts can also be used as water repellents, corrosion inhibitors, petroleum demulsifiers and so on.