Underestimated contribution of HONO to indoor OH radicals: an emerging concern

Indoor Air PollutionWhen we think of air pollution, we often imagine smoggy skies or factory smoke, but indoor air pollution can be just as harmful. Air pollutants like dust, mold, chemicals from cleaning products, smoke, and gases like carbon monoxide can build up inside homes, schools, and buildings. Poor ventilation can make the problem worse, leading to health issues like allergies, asthma, or headaches. Learning about indoor air pollution helps us understand where these pollutants come...

The oxidation of an organic compound in the presence of air or oxygen is called autoxidation. For example, cumene reacts with oxygen to form hydroperoxide. Autoxidation involves initiation, propagation, and termination steps. Many organic compounds are susceptible to autoxidation—especially ethers in the presence of oxygen, which form hydroperoxides. Even though this reaction is slow, old ether bottles contain small amounts of peroxide, which leads to laboratory explosions during ether...

Radicals adjacent to electron-donating groups are called nucleophilic radicals. These radicals readily react with electrophilic alkenes. The SOMO–LUMO interactions are the driving force for the reaction, where the high-energy SOMO of the electron-rich, nucleophilic radicals interacts with the low-energy LUMO of the electron-deficient, electrophilic alkenes. Such SOMO–LUMO interactions are the basis of reactive radical traps, affecting the selectivity in radical reactions. For...

Outdoor Air PollutionAir pollution happens when harmful gases, dust, smoke, or chemicals enter our air. These pollutants can come from cars, factories, wildfires, or everyday activities like aerosol sprays. There are two types of pollution: indoor and outdoor air pollution. Outdoor air pollution, in particular, includes emissions released into the open air, where they mix with the atmosphere and can travel great distances. Polluted air can cause health problems for people, harm animals, damage...

Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by...

Radicals adjacent to electron‐withdrawing groups are called electrophilic radicals. These radicals readily react with nucleophilic alkenes. For example, the malonate radical, in which the radical center is flanked by two electron‐withdrawing groups, reacts readily with butyl vinyl ether, which consists of an electron‐donating oxygen substituent. The reaction between electrophilic malonate radical and nucleophilic vinyl ether is favored because the radical has a...