A new research study led by assistant professor of mechanical engineering at Columbia Engineering, Michael P. Burke has found out the importance of a new kind of chemical reactions that involves three molecules that individually participate in the forming and breaking of chemical bonds. The reaction of these three distinctive molecules is enforced by an ‘ephemeral collision complex’ that is formed after the collision of two molecules, which survives long enough to be able to collide with a third molecule.
This fourth kind of chemical reaction, which the scientists have names as ‘chemically termolecular reactions’ was first proposed by Nikolay Semenov and Cyril Hinshelwood during their research on chain reactions back in 1920s and 1930s. They were awarded with the Nobel Prize in Chemistry for their valuable contribution. For decades, scientists and researchers have deemed these reactions as insignificant – if they even take place at all – and up till now, have been rarely studied. Burke, who analyzes a wide range of problems at the interface between practical engineering devices and fundamental physical chemistry, decided to explore these reactions after understanding that the common combustion conditions, such as those faced in many engines, have ample high fractions of extremely reactive molecules called as free radicals that make these reactions possible. This new study by Burke is published in Nature Chemistry.
With the use of theoretical methods that include those that are developed for this research, the scientists proved that these termolecular chemical reactions not only are substantial chemical pathways but also influence flame propagation momentum, a measure of general reactivity of fuel that governs the stability, performance, and efficiency of many engines of modern times. This finding will open doors to infinite possibilities, from planetary chemistry to new types of designs for engines.