Computational Chemistry, Poster
As if They Were Transition Metal Compounds: the Amazing Electronic Structure and Reactivity of Hypervalent Iodine Reagents
A. H. Pinto de Magalhães1, O. Sala1, A. Togni1*, H. P. Lüthi1*
1ETH Zurich
Hypervalent iodine compounds, in particular trivalent iodine species (l3 iodanes), have become important reagents for the transfer of electrophilic substituents to arenes and other nucleophiles.  However, relatively little is known about the mechanism of these transfers.  Our research has shown that iodanes show a rich and often complex reactivity, reminiscent of the one of organometallics.  Whereas many aspects of the reactivity of these compounds can be expressed by simple “back-of-the-envelope-rules”, the prediction of activation energies may require extended dynamics simulation as entropy contributions may determine the course of a reaction [1].

In this presentation, we explore fundamental aspects of the structure, the bonding and the reactivity of these compounds, whose electronic structure is usually described in terms of a 3-center-4-electron (3c-4e) bond model, involving the iodine central atom and its two trans-substituents; the third substituent is bound by a classical 2-center bond (see figure). Using the Domain Averaged Fermi Hole method, we are able to show which factors govern the formation of 3c-4e bonds, the heart of the iodane reactivity [2].
[1] O. Sala, H.P. Lüthi, A. Togni, M. Iannuzzi, J. Hutter, J. Comp. Chem., 2015, 36, 785.
[2] H. Pinto de Magalhães, H.P. Lüthi, P. Bultinck, PhysChemChemPhys, 2016, 18, 846.