Composing a molecular symphony

Oscillations are all around us. In nature, oscillating systems control many processes, for example the regular beating of our heart. Oscillations can also be found in chemistry. A complex symphony of chemical reactions can cause the concentrations of different chemicals to increase and decrease, producing pulsating color or acidity changes. In our lab we have developed a new chemical oscillator using small organic molecules. In a special reaction chamber where continuously fresh starting material is added and reaction mixture is taken out, the concentrations of the molecules oscillate regularly. But this chemical oscillator is not just a clock. It can catalyze other chemical reactions, resulting in periodic synthesis of new molecules. When there is a lot of catalyst, near the peak of the oscillation, the catalyzed reaction takes place rapidly, but when the catalyst disappears, the catalyzed reaction stops. Being able to trigger/program reactions with an autonomous oscillator opens up new possibilities in chemical synthesis. Feedstocks often consist of mixture of molecules. Doing chemical synthesis with mixtures results a in a mess. Doing clean and selective synthesis requires tedious purification steps, efforts and energy. We can use the catalytic oscillator as a molecular filter for a mixture of chemicals and avoid purification. This is possible because the catalytic oscillator will preferably react with the most reactive molecule in the mixture of similar molecules, before it disappears again. One day the catalytic oscillator could be used for periodic synthesis and delivery of medication, making specialized polymer chains, or controlling molecular machines.

Dissertation: https://hdl.handle.net/11370/656b1aea-155f-43da-8b78-37cca4c9d242