A research team led by two professors from National Chiao Tung University’s applied chemistry department has become one of the first to detect and monitor the Criegee intermediate CH2OO, a molecule originally postulated in 1949, but only recently discovered.
“Criegee intermediates are carbonyl oxides postulated to play a key role in the reactions of ozone with unsaturated hydrocarbons” the team said.
The reactions form an important mechanism for removing unsaturated hydrocarbons and producing hydroxide in the atmosphere, it added.
Criegee intermediates were first proposed by Rudolf Criegee in 1949, but for decades scientists were unable to directly detect and identify the molecules due to their highly active nature and short lifespan.
Last year, a team of researchers from Sandia National Laboratories in the US reported direct measurements of reactions of a gas-phase Criegee intermediate using photo-ionization mass spectrometry.
National Chiao Tung University’s research team, which includes professors Henryk Witek and Lee Yuan-pern (李遠鵬), graduate student Su Yu-te (蘇育德) and doctoral student Huang Yu-hsuan (黃郁琁), has discovered the intermediate’s transient infrared absorption spectrum.
The team said the findings had been possible thanks to a newly improved step-scan Fourier-transform spectrometer that the laboratory had assembled itself.
The discovery may contribute to increased understanding of many different aspects of the atmosphere, such as acid rain, pollutants and climate change.
At a university event on Saturday, school president Wu Yen-hua (吳妍華) praised the team’s achievement, saying that it was an honor that the team’s “100 percent local” research was published in the internationally renowned Science magazine on Friday last week.