Applied Theoretical Chemistry, Structure and Reactivity of Molecules, Clusters and Solids, Aromaticity and Electron Counting Rules, Structure of Elemental Boron and Boron-rich Solids.
We study the structure and reactivity problems of real life molecules, clusters and solids using theoretical techniques ranging from the simplest of molecular orbital methods to the sophisticated electronic structure theory depending on the system at hand and thequestions that are to be answered. Special emphasis is placed in weaving threads between problems in one area to another; between polymorphs of elements and their compounds, between organic and organometallic chemistry, amongst the chemistry of various main group elements; Bonding, Structure and Reactions across the Periodic Table of Elements. We place great importance in not only getting numbers as an answer to a problem, but also in finding out why the numbers turn out the way they do, based on overlap of orbitals, perturbation theory, and symmetry, and in devising transferable models.
The attempt by the Jemmis group is not just to get some calculations and a specific answer, nor to work in a contemporary area where many scientists work, but to develop general understanding of a transferable nature in a chosen area to help further the thought processes in chemistry. This has always led to applications in material science and biology. Majority of his former students work in material science or computaional drug design and molecular modelling.
Our recent Chem. Eur. J. paper Chem. Eur. J. 2017, 23, 9746-9751 showed that Incorporation of a group IV metal fragment ZrCp2 into a borocycle is an effective strategy to stabilize a B-B triple bond in a cyclic system. The characteristic donor-acceptor bonding feature in metallacycloboryne contrasts with the carbon analogues.
The inevitability of holes on borophenes and borospherenes are recently investigated. Using molecular dynamic simulation techniques, we demonstrated the precise structures for borophene phases obtained on Ag surface in our Angew. Chem. article Angew. Chem., 2017, 56, 10093-10097 . While growth temperature controls the density and distribution of holes in borophene, we found that in 3D, symmetry and stability of unit cell varies dramatically depending upon the partial occupancies. The new boron allotrope denoted as tau-boron is one such consequence. Our fragment approach revealed the electronic structure for this form Phys. Rev. B, 2017, 95, 165128.
Electron saturated transition metal complexes of groups 3-10 show reluctance towards weak metal-bond formation. An electronic structure reason for this observation has been provided by us in a recent Inorg. Chem., 2017, 56, 1132-1143paper. Our quantum chemical claculations recently published in Chem. Commun. 2017, 53, 8168-8171unveiled a hitherto unexplored multifacted application of halogen bonding as an electron scavenger.
Fullerenes, and a recently predicted boron analog B80, have spherical shape with nothing inside. Based on quantum mechanical calculations, in an article recently accepted for publication in Physical Review Letters, we predict that boron fullerenes become even more stable if covalently bound boron atoms are placed inside. In arriving at the structures such as B84 we followed the leads from the chemistry of boron. B84 is a building block of beta-rhombohedral boron with a C60-like surface built around a B12 icosahedron. The trick is to make B84 electron sufficient so that it is stable and does not associate to form extended solids. Our earlier work on the structure of elemental boron and condensed boranes helped us to estimate the charge requirement of B84 as 50. If 50 electrons are provided by additional boron atoms, where each boron atom provides three valence electrons, 16.66 additional boron atoms are needed. We still cannot compute fractional atoms in a molecule easily! The closest approach towards the 50 electrons is by adding 16,17, and 18 atoms, making the highly stable clusters B100, B101, and B102. These results emphasize the importance of chemical valence rules and encourage exploration of novel boron based nano materials experimentally. Please see Physical Review Letters, 100, 165504 (2008) and the Virtual J. Nanoscience and technology for details.This is highlighted in many places including Chem and Engg News of 5th May, 2008, under Science and Technology Concentrates, "Getting stuffed improves stability of boron fullerenes".
General Areas of Interest at different times have been labeled for convenience as Theoretical Inorganic Chemistry, Theoretical Organic Chemistry, Computational Chemistry, Transition Metal Organometallics, Electronic Structure and Electron Counting Rules, Three Dimensional Aromaticity, and, Molecular Modeling and Computational Drug Design. Current projects include Reactions of (C5H5)2Ti, (C5H5)2Zr Complexes, C-H, C-X, Si-H Bond Activation, Huckel 4n+2, Wade's n+1 and Jemmis mno Rules: Comparisons and applications, Electronic Structure of elemental boron and boron rich-solids, Boron Fullerenes and Nanotubes, Metallocene analogs with Phosphorus rings, Electronic Structure Description of Improper and anti-Hydrogen Bonds, Nickel Mediated Benzyne and Carboryne coupling with acetylenes, Stabilization of unusual coordination numbers and geometries, Cycloadditions involving fullerenes, Structure based approaches to Lead-optimization and Study of PDE-4 (Phosphodiesterase) Inhibitors, and Mechanism of alpha aminoxylation.
Please see News for research opportunities.
Our recent Angew.Chem. article on C-H and Si-H bond activation was selected for cover page of the 4th September 2007 issue of the journal. The Chemical and Engineering News has included this article in their report, Happening Hafnium, which appeared this week (8th October, 2007).
A write-up on boron clusters, boranes and our analogies to carbon BORON FLAT OUT , is available on the March 1st (2004) issue of Chem & E ngg News.The new edition of the inorganic chemistry text book (2003) by Gary L. Miessler and Donald A. Tarr gives a two page description on the mno rule. There is a low priced edition available in India published by Pearson Education.
A popular write-up on our MNO RULE AND THE BETA-RHOMBOHED RAL BORON CONNECTION , is available on the June 4th (2001) issue of Chem & Engg News, written by Stephen Ritter, Senior Editor of CandEN.