Isoprene, C5H8, is by far the most important biogenic volatile organic compound (BVOC) emitted to Earth鈥檚 atmosphere.听听It undergoes atmospheric oxidation during the day by OH, and by O3and NO3at night.听听The NO3oxidation represents one of the mechanisms by which anthropogenic pollution in the form of nitrogen oxides (NOx) interacts with biogenic cycles and may be an efficient route to the formation of secondary organic aerosol (SOA) from isoprene oxidation.听听The SAPHIR chamber at the in Germany is a state-of-the-art facility for the investigation of atmospheric chemical mechanisms.听听The 2018 study was a comprehensive investigation of the NO3-Isoprene study to elucidate major oxidation pathways, peroxy radical chemistry, key reactive intermediates, and SOA.