by Violet Wallerstein
Dr. Mary-Ann Pearsall, a member of the Drew faculty since 1988, is an organometallic chemist by training, so she works with metal atoms that are bonded to carbon. Her lab focuses on the atom osmium (Os) and how it functions with biological molecules.
Below is a picture of the molecule she works with most often. There are two ethoxides that bridge the two Os atoms. Dr. Pearsall decided to work with this because “no one really works with this, and nobody knows what happens when you have two ethoxides instead of one or zero.”
In her lab, she and her students replace some of the groups on the molecule with other atoms or functional groups. They are trying to discover what can be done with the molecule and what reactions and systems could be useful. Recently, her lab has discovered that you can replace one of the ethoxides with an amine and is now trying to see if there are any useful biological functions of the molecule, such as anti-cancerous properties.
Dr. Pearsall started her research with osmium as part of her Ph.D. and has been working on it ever since. “When we get the data we have to think about fundamental bonding. These are the sort of things I teach in Inorganic Chemistry, which is my thing,” she said. “It still has surprises and we don’t know what it’s going to do. We have done reactions that have products that no one has ever made before, which is incredible. It may also be helpful and teach us about bonding in transition metal compounds.”
She has had some roadblocks in her research during her time here at Drew. The lab was receiving their osmium source as a by-product from another lab, but the source stopped creating the by-product. Dr. Pearsall and her lab had to figure out how to make it, which took five years of research to perfect the synthesis.
Dr. Pearsall’s office is on the third floor in the Hall of Sciences, and her research is conducted in the new lab there as well. She teaches Inorganic Chemistry, as well as the advanced section of the first semester of General Chemistry.