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?