Zintl and Polar Intermetallic Compounds

Chemistry Department Seminar Faculty Candidate
Dr. Fei Wang

Polymer and Material Chemistry, Lund University Sweden
Monday April 6, 2015
4:00 PM, MUB~ Alumni Lounge A

Zintl and polar intermetallic compounds are compounds between electropositive metals (e.g. alkali, alkaline earth, and rare earth) and electronegative metals/metalloids (e.g. late transition and post transition elements). Just like their constituent elements, these compounds are also metals/metalloids. Meanwhile, partial charge transfer is expected from the electropositive metals to the electronegative metals/metalloids, the latter of which are formal “anions” and covalent interactions can occur among them. Therefore, Zintl and polar intermetallic compounds possess simultaneously metallic, ionic, and covalent characteristics. I will demonstrate what will happen when metallicity, covalency, and ionicity coincide and interplay with each other.
Besides, the bonding between the “anionic” electronegative metals/metalloids is also intriguing. The well-know electron counting rules, such as the octet rule and the Wade-Mingo’s rules, fail frequently in rationalizing the bonding in Zintl and polar intermetallic compounds. I will present a few examples to illustrate the cause, with emphasis on the involvement of d-orbitals and the relativistic effects in bonding.

I obtained my master’s degree from Zhejiang University in China in 2005. There I worked on morphology controlled syntheses of inorganic compounds under the direction of Prof. Linhai Yue. After that, I joined Prof. Gordon J. Miller’s research group in Iowa State University, where I developed the majority of my expertise in solid state chemistry, including high temperature synthesis, X-ray crystallography, and first-principle computations. In 2011, I received my PhD degree in inorganic chemistry and moved to Stuttgart, Germany, working as a postdoc in Prof. Martin Jansen’s department in Max Planck Institute for Solid State Research. My project is on the syntheses, structures, and rationalization of thallium cluster compounds featuring significant relativistic spin-orbit coupling. Currently, I am in Prof. Sven Lidin’s group at Lund University in Sweden, working on my second postdoc position which started in 2013 and is supported by the Wenner-Gren Scholarship. Here, my expertise has been further broadened with incommensurate crystallography and thermoelectric materials.