What is it about?
An intermediate called Criegee intermediate generally forms in the gas phase ozonolysis of the alkenes, which is very important in the atmospheric regime. This study determines the kinetics of one of these radicals (CH2OO) with a ketone (methyl-ethyl ketone, CH3COC2H5) relevant to Earth's atmosphere.
Featured Image
Photo by Scott Webb on Unsplash
Why is it important?
The short-lived Criegee intermediates react with atmospheric VOCs and get isomerised into compounds or carboxylic acids. They also convert the low molecular weight VOCs into low volatile oxygenated compounds, ultimately generating precursors for the secondary organic aerosol, and hence directly affecting the air quality. Criegee intermediates, during their unimolecular decomposition, release OH radicals, which are the most dominant oxidant in the atmosphere and are also known as the detergent of the atmosphere. Hence, to model the reaction of Criegee intermediates, the rate coefficients measurement of the Criegee intermediates with known VOCs is very important. n-butyraldehyde and isobutyraldehyde are among the VOCs that have not yet been explored.
Perspectives
In this study, the reaction kinetics for CH2OO with nBD and iBD were determined by direct probing of CH2OO using a highly sensitive custom-built Cavity Ring-down Spectrometer (CRDS). The rate coefficients were measured at various temperatures and were verified using computational calculations. The proposed reaction pathways were evaluated in terms of thermochemical and kinetic parameters. The implications of the title reactions were discussed on the basis of certain crucial parameters, which influence the atmosphere.
Amit Debnath
Indian Institute of Technology Madras
Read the Original
This page is a summary of: Experimental and theoretical study of Criegee intermediate (CH2OO) reactions with n-butyraldehyde and isobutyraldehyde: kinetics, implications and atmospheric fate, Physical Chemistry Chemical Physics, January 2024, Royal Society of Chemistry,
DOI: 10.1039/d3cp05482a.
You can read the full text:
Contributors
The following have contributed to this page
