Puru Jena

Title : Chemistry beyond conventional wisdom

Abstract:

The chemistry of elements in the periodic table, created by Mendeleev in 1869 before the discovery of the electron and the knowledge of quantum mechanics, can be explained in terms of their valence electrons and the orbitals they occupy. For example, noble gas atoms, with filled outer electron orbitals (ns² np⁶) are chemically inert. Similarly, zinc, with an outer electron configuration of filled s shell (4s²) is divalent and interacts weakly another Zn atom. But bulk Zn is not chemically inert; it is metallic. Zinc assuming an oxidation state of +III and noble gas atoms forming chemical bonds at room temperature are against conventional wisdom. In this talk I will discuss ways in which zinc can be in a +III oxidation state and noble gas atoms, including argon, can form a covalent bond at room temperature. These unexpected features are made possible by the use of highly stable super-electrophilic clusters. In particular, BeB₁₁(CN)₁₂ and BeB₂₃(CN)₂₂ clusters, which are, respectively, stable as tri-anion and tetra-anion in the gas phase, can make Zn to assume +III oxidation state. On the other hand, B₁₂(CN)₁₁^- cluster can bind argon with a binding energy of 0.6 eV. These results, based on density functional theory with dispersion correction, have predictive capability and provide a path to manipulate text book chemistry. The rational design of clusters with electron affinities far exceeding those of halogen atoms and their ability to promote chemical reactions once thought impossible can usher a new era in chemistry.

Audience take-away:

• How chemistry of elements can be fundamentally changed?
• How such knowledge can be used to promote reactions, once thought impossible?
• How this knowledge can create new materials with tailored functionalities?

Biography:

Dr. Puru Jena, Distinguished Professor of Physics at Virginia Commonwealth University, received his Ph. D. from the University of California, Riverside. He also served as Program Director at the Materials Science Division of the National Science Foundation during 1986-87 and as Jefferson Science Fellow and Senior Science Advisor at the US Department of State during 2007-08. Dr. Jena’s research covers a wide range of topics in nano-structured materials, condensed matter Physics, and materials Science. He is the author of more than 650 papers including 14 edited books. According to Google scholar, he has an H index of 90 and his papers have been cited 34,000 times. He has given over 500 invited talks in 33 countries, including over 250 invited talks at international conferences and has organized 60 international conferences.Some of Dr.Jena’s many honors include: Prof. A. K. Chandra Memorial award of the Indian Chemical Society, Fellow of the American Physical Society; Outstanding Scientist of Virginia; Presidential Medallion, University Award of Excellence, and Outstanding Scholar of Virginia Commonwealth University; and Outstanding Faculty Award from the State Council of Higher Education of Virginia. He has served as a member of numerous scientific panels at the National Academy of Sciences, National Science Foundation, Department of Energy, Army Research Office, Virginia Governor’s task force on green energy technologies and co-chaired the Presidential Commission on bilateral scientific collaboration between USA and Russia.