As my public profile increases more and more, I get loads of question from people about my research, what’s my range of expertise and if I am a real scientist. I am a 4th year PhD student in Sustainable Chemistry. I started my PhD in 2015 and I will finish this year, hopefully! I am on a fully funded research project and I started my PhD with a master in Green Chemistry. I designed my initial research proposal and pitched to a panel of academics and industrial folks but it didn’t go very well, so I am working on totally different stuff now.
I get loads of questions including if I am a real scientist
In the big scheme of things, I am working on catalysis, which means finding ways to speed up chemical reactions. The way we do it is by using a catalyst. The best way to explain the concept of catalyst is by using the metaphor of the tunnel (see pic. foto credit sciencenews.org). So, we have to go from point A to B, which translated to chemistry means going from your starting material to a product. To do that, we have to overcome a mountain. Our first option is to go all the way to the top and climb down, which takes loads of time and energy. Or we can dig a tunnel and get cross the mountain in a faster and less energetic way.
In chemistry, digging the tunnel is the equivalent of finding a catalyst
I am currently working on Suzuki-Miyaura coupling reactions. In 1970, Suzuki and his postdoc Miyaura found a new reaction that allowed the formation of Carbon-Carbon bonds by using small (in jargon, catalytic) amounts of Palladium. (1) Previous attempts to carry out such transformation using a tiny amount of palladium failed. But in the presence of a base, such as sodium hydroxide, the reaction occurred really well. It was a revolution in the chemistry world as it made literally the impossible possible. Carbon-Carbon bonds are ones of the most important in organic chemistry and the most widely spread in nature too.
The Suzuki-Miyaura coupling reaction finds loads of application in the pharma, agrochemical and fine chemical industry. (2) For its importance, the reaction was awarded the Nobel Prize in 2010. (3) About the catalytic cycle (3) Skip if not interested: heavy chemistry. The precatalyst is a Pd(2+) species which is converted into a Pd(0) by a base. Pd (0) undergoes oxidative addition and binds the aryl halide. We get Pd(2+) again. After the transmetallation, both coupling partners are bound to Pd and we get the product and the formation of a new C-C bond. A typical set up is shown in the figure. I use a shlenck line (all the red and blue taps in the feature picture) and schlenk equipment, which is a pretty standard set up when working whit palladium. In fact, the reaction is sensitive to oxygen, so I remove it and fill my tubes with nitrogen. I then put my reaction in a hot plate, the metal round-shaped thing (pic below) and leave there overnight. I then analyse all my reaction with fluorine NMR which is a pretty standard way of screening reaction in this field.
For its importance, the reaction was awarded the Nobel Prize in 2010
Despite the importance of the Suzuki-Miyaura coupling for the chemical industry and its wide use in electronic devices such as your smartphone, there is a widespread negative attitude towards palladium. This is because the use of palladium isn’t quite sustainable.
In the last 3 decades, its cost became ridiculous (4) due to the high demand. Mining for extracting these metals is destroying the environment, releases great quantities of greenhouse gasses into the atmosphere and vast use of water. (5) Little quantities of this metal are currently recycled and it is highly toxic because it messes up with some biological processes. (6)
In my opinion, all these findings shouldn’t sound too much scary but provide new challenges and opportunities for academic research and sustainability
(1) Tetrahedron Lett. 1979, 20, 3437–3440.
(2) Adv. Synth. Catal., 2009, 351, 3027-3043.
(3) Angew. Chem. Int. Ed., 2011, 50, 6722-6737.
(5) Minerals Engineering, 2010, 23, 438–450, http://users.monash.edu.au/~gmudd/files/2009-CMS-02-Platinum-PGMs-v-Sust.pdf
(6) J. Environ. Sci. Health. A Tox. Hazard. Subst. Environ. Eng., 2006, 41, 397-414.