Organic Chemistry Seminar

Title:

The Advent of Conceptual Noncovalent Interaction-inclusive Molecular Engineering in Transition Metal Organometallic Chemistry: T-shaped complexes, Reactive Metal-Silicon Intermediates and Predictive Approaches

Abstract:

Non-covalent interactions (NCIs) are ubiquitous in Nature and their influence on the structures and properties of chemical systems is now well established.1 Their role is increasingly being considered even in the most intimate aspects of transition metal promoted catalysis.2 In this lecture, the importance of NCIs in coordination and organometallic chemistry will be introduced through the prism of our synthetic and fundamental research on the origin of the stabilization of electron-unsaturated metal centers (Pd(II), Pd(I), Pt(II), Mn(I), Re(I), Rh(I)) by the so-called “hemichelation”.3 This mode of coordination which was proposed in 2013 has in fact a few examples that can be found in the 1990’s literature. The introduction of DFT-D methods, the popularization of QTAIM and derived methods, the development of new WFT methods altogether allow us nowadays to throw a new light on the manner ligand–to-metal and inter-metallic interactions do establish and how a more NCIinclusive analysis of chemical bonding can improve molecular and catalysis engineering. A few examples will address our recent work on the mode of activation of hydrosilanes by iridacycles, which leads to unique donor-acceptor type of iridium (III)-silylium reactive intermediates.4 Finally, a short presentation of one example of predictive approach of C-H bond activation by 3d metal centers will be disclosed.5

References:

(1) Petrovic, P.; Djukic, J.-P.; Hansen, A.; Bannwarth, C.; Grimme, S. Non-covalent stabilization in transition metal coordination and organometallic complexes; John Wiley & Sons, Inc., 2016.

(2) Hamdaoui, M.; Djukic, J.-P. In Noncovalent Interactions in Catalysis; Mahmudov, K. T., Kopylovich, M. N., Guedes_da_Silva, M. F. C., Pombeiro, A. J. L., Eds.; The Royal Society of Chemistry: 2019, p 579-607.

(3) (a) Werle, C.; Bailly, C.; Karmazin-Brelot, L.; Le Goff, X.-F.; Ricard, L.; Djukic, J.-P. Hemichelation, a way to stabilize electron-unsaturated complexes: the case of T-shaped Pd and Pt metallacycles. J. Am. Chem. Soc. 2013, 135, 17839-17852. (b) Werle, C.; Hamdaoui, M.; Bailly, C.; Le Goff, X.-F.; Brelot, L.; Djukic, J.-P. Electron-Deficient η1-Indenyl,η3-allylpalladium(II) Complexes Stabilized by Fluxional Non-covalent Interactions. J. Am. Chem. Soc. 2013, 135, 1715-1718. (c) Werle, C.; Bailly, C.; Karmazin-Brelot, L.; Le Goff, X.-F.; Pfeffer, M.; Djukic, J.-P. First Stabilization of 14-Electron Rhodium(I) Complexes by Hemichelation. Angew. Chem., Int. Ed. 2014, 53, 9827-9831. (d) Werle, C.; Dohm, S.; Bailly, C.; Karmazin, L.; Ricard, L.; Sieffert, N.; Pfeffer, M.; Hansen, A.; Grimme, S.; Djukic, J.-P. Trans-cis C-Pd-C rearrangement in hemichelates. Dalton Trans. 2017, 46, 8125-8137. (e) Werle, C.; Bailly, C.; Karamazin, L.; Djukic, J. P. Effect of Enhanced Electron Withdrawal on the Cohesion of Cr-Pd Hemichelates. Eur. J. Inorg. Chem. 2019, 3301-3308. (f) Werle, C.; Karmazin, L.; Bailly, C.; Ricard, L.; Djukic, J.-P. Stabilization of an Electron-Unsaturated Pd(I)-Pd(I) Unit by Double Hemichelation. Organometallics 2015, 34, 3055-3064.

(4) (a) Hamdaoui, M.; Ney, M.; Sarda, V.; Karmazin, L.; Bailly, C.; Sieffert, N.; Dohm, S.; Hansen, A.; Grimme, S.; Djukic, J.-P. Evidence of a Donor-Acceptor (Ir-H)→SiR3 Interaction in a Trapped Ir(III) Silane Catalytic Intermediate. Organometallics 2016, 35, 2207-2223. (b) Binh, D. H.; Milovanovic, M.; Puertes-Mico, J.; Hamdaoui, M.; Zaric, S. D.; Djukic, J.-P. Is the R3Si Moiety in Metal-Silyl Complexes a Z ligand? An Answer from the Interaction Energy. Chem. - Eur. J. 2017, 23, 17058-17069. (c) Hamdaoui, M.; Desrousseaux, C.; Habbita, H.; Djukic, J.-P. Iridacycles as Catalysts for the Autotandem Conversion of Nitriles into Amines by Hydrosilylation: Experimental Investigation and Scope. Organometallics 2017, 36, 4864-4882. (d) Binh, D. H.; Hamdaoui, M.; Fischer-Krauser, D.; Karmazin, L.; Bailly, C.; Djukic, J.-P. Entrapment of THF-Stabilized Iridacyclic IrIII Silylenes from Double H−Si Bond Activation and H2 Elimination. Chemistry – A European Journal 2018, 24, 17577-17589.

(5) Cornaton, Y.; Djukic, J.-P. A noncovalent interaction insight onto the concerted metallation deprotonation mechanism. Phys. Chem. Chem. Phys. 2019, 21, 20486-20498.

Event Organizer: Dr. Roman Dobrovetsky