NOHSO4

NOHSO₄, or nitrosyl tetraoxosulfate, is an inorganic compound with the chemical formula NOHSO₄. It is a highly reactive and unstable species, typically studied in the context of atmospheric chemistry and gas-phase reactions. The compound is often discussed in relation to its role in the formation of secondary pollutants, particularly in urban environments where nitrogen oxides (NOₓ) and sulfur dioxide (SO₂) coexist.

NOHSO₄ is believed to form through the reaction between nitrous acid (HNO₂) and sulfur trioxide (SO₃) or sulfuric acid (H₂SO₄) under certain atmospheric conditions. Its transient nature makes direct experimental observation challenging, but theoretical and computational studies have provided insights into its structure and reactivity. The molecule is thought to exist primarily in the gas phase, where it may participate in radical chain reactions that influence air quality and climate.

In atmospheric chemistry, NOHSO₄ is relevant due to its potential role in the formation of fine particulate matter (PM₂.₅) and aerosol particles. These particles can have significant environmental and health impacts, contributing to haze, acid rain, and respiratory issues. Research into NOHSO₄ helps scientists better understand atmospheric oxidation processes and the interplay between nitrogen and sulfur cycles.

Due to its instability, NOHSO₄ is not typically isolated or stored in bulk. Instead, its behavior is inferred through laboratory simulations and field measurements of related species. Studies often rely on computational chemistry to model its structure and reaction pathways, aiding in the development of atmospheric models that predict pollutant formation and dispersion.