Chemical Waves, Swirls, and Shapes in a Dish

After listening to the introduction to a very perplexing lab presentation that mentioned how some specific chemical reactions seem to break the Second Law of Thermodynamics, I wondered what in the world I got myself into observing. The Ph.D. student who was presenting talked about how the chemical reaction he was about to perform would demonstrate a type of chemical oscillation that could be a breakthrough in determining the chemistry of the prebiotic soup from where all life arose. Via these chemical oscillations (specifically, the rapidly fluctuating oxidation state of Iron in solution), when mixed in solution with the right compounds and phospholipids (the building blocks of biological cell membranes), can create shapes such as the spiral or wavy forms of shells. This study has the ultimate goal of explaining how biological shapes formed in pre-biotic soup.

The compound that was used in the lab presentation was ferroin, a tri-phenolic bidentate ligated to an Iron atom. This compound is added to a solution containing decomposing CH(COOH)2Br. Due to the reaction conditions, the iron will ligate differently with the intermediate compounds, and these repeated fluctuations have a physical starting point, will spread along a front, and will repeat themselves, very similar to observing ripples form in water. When phospholipids are added to the reaction mixture, they organize themselves into the shapes of the reactions as spirals, waves, and ripples and also exhibit interference when two fronts collide.