Nitriittiion

Nitriittiion is the chemical species with the formula NO2-. It consists of one nitrogen atom covalently bonded to two oxygen atoms, with a net charge of -1. The nitrite ion is a linear molecule with resonance structures that contribute to its overall stability. It is an important species in various chemical and biological processes.

In chemistry, nitrite is often encountered as a salt, such as sodium nitrite (NaNO2) or potassium nitrite (KNO2). These salts are soluble in water and readily dissociate into their respective cations and the nitrite ion. Nitrite is a reducing agent and can be oxidized to nitrate (NO3-). Conversely, it can also be reduced to nitric oxide (NO) under certain conditions.

Biologically, the nitrite ion plays a role in the nitrogen cycle, particularly in nitrification and denitrification processes carried out by microorganisms. It is an intermediate in the conversion of ammonia to nitrate. In the human body, nitrite can be formed from dietary nitrates and, under specific conditions, can be converted to nitric oxide, a signaling molecule involved in vasodilation and other physiological functions. However, nitrite can also react with amines to form nitrosamines, some of which are carcinogenic. This is a concern in food preservation, where nitrites are sometimes used as curing agents in processed meats, though their use is regulated due to potential health risks.