Absorption cross-sections of HOCH2OOH vapor between 205 and 360 nm at 298 K

The gas-phase absorption spectrum of hydroxymethylhydroperoxide (HOCH2OOH; HMHP) at 298 K was recorded in the range from 205 to 360 nm using a diode array spectrometer. The concentration of HMHP was determined by FTIR spectroscopy. Its corresponding atmospheric photodissociation rates for mid-latitudes at ground level are estimated to be ∼2.7×10−6 s−1 for 30°, 1.9×10−6 s−1 for 50° and 8.4×10−7 s−1 for 70° zenith angle.