Lisa Szczepura

Research Interests & Areas

Significance of Research. As a synthetic chemist, my research efforts focus on preparing new chemical compounds from smaller, previously reported or readily available, starting materials. Specifically, we work with transition metal clusters. Once the metals are assembled into clusters, we incorporate new terminal ligands (L) and investigate the physical properties and reactivity of the resulting compounds. Goals of the research are aimed at developing synthetic methodologies for the design of unique clusters with novel physical properties and unique reactivity. There are key features which make these clusters well suited for a variety of important applications such as imaging, battery materials and catalysis. While our studies are fundamental in nature, we have had an impact in the field.

Key contributions to the discipline include:
•The discovery that rhenium chalcogenide clusters activate small molecules via ‘click chemistry’, a term that describes high yield reactions occurring under mild conditions, with few, if any, unwanted byproducts. While the advantages of this type of chemistry are numerous, especially in industrial processes, prior to our studies only a handful of metal complexes demonstrated click chemistry. Our most recent manuscript on this project was published last year (Dalton Trans. 2018, 47, 4653, https://pubs.rsc.org/en/content/articlelanding/2018/dt/c7dt04907b/unauth). These findings were significant in that we established the ability of these clusters to perform unique transformations, opening up the possibility of using these clusters as catalysts, something that had not been imagined previously.

•Investigating the viability of cluster based solids as cathode materials in rechargeable lithium batteries. These studies are being conducted in collaboration with researchers at Stony Brook University (Drs. Esther Takeuchi, Kenneth Takeuchi and Amy Marschilok). Our first study, highlighting the high stability and high rate capability of cluster-based materials, was published as a communication in Inorganic Chemistry (2018, 57, 4812, https://pubs.acs.org/doi/pdf/10.1021/acs.inorgchem.8b00499 ). We are currently conducting studies on clusters containing more earth abundant transition metals.

•Preparation of the first hexanuclear clusters containing carbene ligands (Chem. Commun. 2015, 51, 10536, https://pubs.rsc.org/en/content/articlelanding/2015/cc/c5cc03215f/unauth ). The preparation of these carbene clusters has been attempted by others, without success. Organometallic complexes (i.e. metal complexes containing carbon based ligands) play an extremely important role in synthetic and industrial chemistry, and carbene ligands are particularly valuable in facilitating key organic transformations. This report ushered in a new area of carbon based ligands for these cluster complexes and we are only beginning to examine the preparation and study of clusters containing more reactive carbon-donor ligands.

•An invited review chapter included in a special issue of Structure and Bonding (2019, 180, 75). This issue was dedicated to Marcel Sergent, a pioneer in the study of rhenium-based cluster complexes. This chapter reviews key synthetic methodologies that have been developed (by us and other researchers) which are necessary for the ultimate design of clusters for specific applications.