Inorganic Chemistry Seminar: Professor Alexandra Velian, University of Washington
Inorganic Chemistry Seminar: Professor Alexandra Velian, University of Washington (Host: Hema Karunadasa)
**This seminar is available for in-person attendance.**
"Atomically Precise Clusters with an Edge"
About the Seminar
Understanding and controlling catalytically active sites is the holy grail of nanoscale catalysis, promising to unlock fundamental insights into their mechanism and facilitate the creation of catalysts designed for specific transformations. Atomically precise nanoclusters could enable incorporating molecular precision in the design and mechanistic study of active sites. However, to unlock their potential for catalysis, synthetic innovations are required to prepare monodisperse clusters at scale and to exercise precise control over their surface chemistry and composition. Combining molecular precision and scalability with catalytic competence, our group introduced a family of molecular clusters M3Co6Se8L6 (M = Cr, Mn, Fe, Co, Cu, Zn, Sn; L = Ph2PNTol–) that incorporate three chemically addressable edge sites (M) on the surface of a Co/Se cluster core. This synthetic construct is reminiscent of a broad class of catalytically active edge-doped transition metal dichalcogenide nanomaterials. Hemilabile edge–support interactions stabilize the three edge sites in protected low-coordinate states, positioning them to function as catalytically active sites and enabling the systematic study of electronic metal–support interactions, as well as allosteric effects and multi-site dynamics on the cluster surface. M3Co6Se8L6 clusters are not only functional models for heterogeneous single-atom group transfer catalysis, but also a powerful platform to study the dynamics of neighboring active sites in heterogenous catalysts.
About the Speaker
Alexandra began her independent career at the University of Washington in 2017. Research in the Velian group has two main objectives: i) to create next-generation catalysts geared to turn green-house gases like methane and carbon dioxide into value added products, and ii) to develop scalable synthetic strategies to assemble quantum materials poised to defy Moore’s law, such as two-dimensional crystals, into heterostructures with ad-hoc properties.
Alexandra’s scientific and academic contributions have been recognized with several awards and distinctions, including the Cottrell Scholar Fellowship (2020), the NSF Career Award (2019), the Young Investigator Award – ACS Division of Inorganic Chemistry (2016) and the Alan Davison Prize for the Best Thesis in Inorganic Chemistry at MIT (2015) among others.
Alexandra completed her undergraduate studies in chemistry at Caltech, where she conducted research primarily with Professor Theodor Agapie. As the first member of his group, she developed the synthesis of low-valent mono- and bimetallic complexes supported by a terphenyl diphosphine framework.
She received her Ph.D. under the direction of Professor Christopher C. Cummins at MIT, where she developed the synthesis of anthracene and niobium-supported precursors to reactive phosphorus fragments and studied their behavior using chemical, spectroscopic, and computational methods. Notably, this work gave rise to the synthesis of the 6π all-inorganic aromatic anion heterocycle P2N3−, produced in the “click” reaction of P2 with the azide ion.
Following her PhD, Alexandra was a Materials Research Science & Engineering Center postdoctoral fellow with Professor Colin Nuckolls at Columbia University, where she worked on creating well-defined functional nanostructures by linking atomically precise metal chalcogenide clusters.
Image credit: Dennis Wise