The role of sunlight in creating new chemicals

Scientists at the University of Sydney, Australia, discovered the sun's mechanism of rearranging atoms of molecules to form new chemicals.

The results of the study have been published in the recent issue of Nature Chemistry, published by Professor Scott Kable, Dr. Meredith Jordan and collaborators at the School of Chemistry. The results of this study are not only significant in helping to determine the extent to which contaminants can spread across the earth's surface, but also help provide a way to solve how quickly remove these contaminants.

Scientists have shed light on the role of sunlight in disturbing atoms to create new chemicals.

So far, the interaction model of atmospheric chemicals suggests that a molecule emitted into the atmosphere remains fixed until it either undergoes photolysis (subdividing) by light. bright sun, or attacked by other molecules.

Currently, Professor Kable and Dr. Jordan reverse this theory by using a small, polluting molecule, which is very commonly used, called acetaldehyde in the laboratory, based on replacement. Sunlight with laser light.

" We chose the special variant of acetaldehyde compound, 3 of the 4 hydrogen atoms were replaced by" heavy hydrogen "(also known as 1H or 1D deuterium) ," Professor Kable explained.

" While not changing any chemical or photochemical properties to any significant extent, subtle chemical changes have allowed us to monitor photochemical reactions with more details. . "

Professor Kable said that the pattern of interaction of atmospheric chemicals is often predicted: by absorbing only light, the acetaldehyde compound will be broken in half .

" Our experiments show that the atoms in the molecule have been much disturbed, namely heavy hydrogen and hydrogen atoms are disturbed, before acetaldehyde breaks ."

Acetaldehyde is converted into various chemicals during the disturbance process. The most important of these new chemicals is vinyl alcohol, which has very different photochemical properties than acetaldehyde and is removed from the air through various processes.

" Our research shows that chemical compounds such as acetaldehyde, when released into the air, will turn into other chemicals before the sun have the opportunity to destroy them ," Professor Kable said.

" If the molecules are being transformed by sunlight, the chemical composition of the atmosphere is actually a lot more complicated than what we already know ."

Although the results of this study are changing people's scientific understanding of how pollutants are released through the air, Professor Kable noted carefully: There will be no change in tissue. global warming. " Almost all of the carbon atoms present in compounds present in the air will eventually transform into carbon dioxide. The results of this study will not change the model of atmospheric CO ₂ emissions. , "he said.

The article " Nearly the H / D exchange threshold in the CD ₃ CHO photosynthesis ," was published in the Journal of Nature Chemistry, May 23, 2011, by Professor Scott Kable, Dr. Meredith Jordan.