Molecular architect

Samantha Smith
Fall 2017

Samantha Smith of the University of Toronto­ is devising­ new catalysts and ligands­ to enhance the creation of chemicals in industry and the pharmaceutical sector. 

Samantha Smith sees many similarities between an architect who designs buildings and a chemist who undertakes molecular architecture.

Smith, who is nearing the end of her PhD studies in organometallic chemistry at the University of Toronto, says that molecules must be built to withstand outside forces, just like buildings. For example, if you want to make a catalyst that is stable under an oxygen atmosphere, you have to design it with certain features that inhibit reactions with O2. “I like the idea of molecular architecture: you design it, make a synthesis plan, then make something you can characterize and figure out what it looks like on a molecular level,” says Smith. “I’ve always found it interesting and gratifying to build something from the atoms up.” 

Catalysts are one of several areas where Smith has developed expertise in her short but stellar academic career. She is the co-author of 10 journal articles (including some still in preparation) and a frequent presenter on catalyst research at conferences. Her interest in catalysts is rooted, she says, in pragmatism. “I’m a realist,” she says. “A huge percentage of industrial processes utilize catalysts, so it’s very relevant to society in general.” 

Smith is also driven by idealism, which includes incorporating green chemistry into her research. The strategic use of catalysts, she points out, is one of the 12 principles of green chemistry; catalytic reagents are preferred over stoichiometric reagents because they can be reused, avoiding waste and reducing the amount of toxic compounds going into the environment.

In this vein, Smith is exploring the development of new iron- and manganese-based catalysts for asymmetric hydrogenation. A technique commonly used in pharmaceutical laboratories, asymmetric hydrogenation is considered an atom-economical reaction — another key green-chemistry concept that emphasizes efficient conversion of chemical reactions. Smith’s research into this area focuses on replacing heavy and exceptionally rare transition metals such as ruthenium, osmium, iridium and rhodium used for catalysts with more abundant metals that could match these materials in performance. This new area of research, called abundant metal hydrogenation, shows promise, says Smith. Iron, for example, which is abundant, could replace ruthenium, reducing the high cost of pharmaceutical production as well as the need for mining and refining this rare platinum metal. 

Part of catalyst enhancement is the creation of new ligands. These, says Smith, are the “costly part of these catalysts.” Some researchers are investigating how to make ligands using abundant — and thus cheap — natural products. If cheap ligands and catalysts can coalesce, it would change the face of manufacturing and pharmaceuticals. This past summer, Smith spent three months in Germany in an inorganic laboratory affiliated with the University of Münster. Here, she redesigned ligands used in asymmetric hydrogenation to enhance the efficacy of catalysts.

Smith’s artful engagement with the world goes beyond the chemistry lab. Her sensitivity towards the environment is reflected in her personal life: she eschews plastic, takes public transportation, makes her own milk from nuts, brews her own beer and spends her spare time outdoors rock climbing, running and cycling. She is also an enthusiastic tutor to chemistry and mathematic students (as an undergrad at Wilfrid Laurier University in Waterloo, Ont. she did a double major in chemistry and math). She also volunteers extensively with the Chemical Institute of Canada and U of T’s Green Chemistry Initiative, organizing symposia.

Smith sees volunteering as an undertaking that is “moral — giving back to the community.” It also builds organizational and people skills, making job hunting a little less onerous upon graduation. “Volunteering will put you ahead of others who don’t have the skills that you’ve gained,” says Smith. “Volunteering is one of the most satisfying things that I’ve done.”