Nitroxide
An amine oxide, also known as amine-N-oxide and N-oxide, is a chemical compound that contains the functional group R3N+–O−, an N–O bond with three additional hydrogen and/or hydrocarbon side chains attached to N. Sometimes it is written as R3N→O or, wrongly, as R3N=O.
In the strict sense the term amine oxide applies only to oxides of tertiary amines. Sometimes it is also used for the analogous derivatives of primary and secondary amines.
Examples of amine oxides include pyridine-N-oxide, a water-soluble crystalline solid with melting point 62–67 °C, and N-methylmorpholine N-oxide, which is an oxidant.
Amine oxides are surfactants commonly used in consumer products such as shampoos, conditioners, detergents, and hard surface cleaners. Alkyl dimethyl amine oxide (chain lengths C10–C16) is the most commercially used amine oxide. They are considered a high production volume class of compounds in more than one member country of the Organisation for Economic Co-operation and Development (OECD); with annual production over 26,000, 16,000 and 6,800 metric tons in the US, Europe, and Japan, respectively. In North America, more than 95% of amine oxides are used in home cleaning products. They serve as stabilizers, thickeners, emollients, emulsifiers and conditioners with active concentrations in the range of 0.1–10%. The remainder (< 5%) is used in personal care, institutional, commercial products and for unique patented uses such as photography.
Amine oxides are used as protecting group for amines and as chemical intermediates. Long-chain alkyl amine oxides are used as amphoteric surfactants and foam stabilizers.
Amine oxides are highly polar molecules and have a polarity close to that of quaternary ammonium salts. Small amine oxides are very hydrophilic and have an excellent water solubility and a very poor solubility in most organic solvents.
...
Wikipedia