Prominent unresolved question in modern chemistry is about mechanistic effect(s) of multi-scale nuclear motion in elementary steps of chemical reactions. Frustrated Lewis acid/base pairs (FLPs for short) have added new facets to this interdisciplinary question. Latest results of our group concern with microscopic origins of the molecular dynamics effects in mechanisms of FLP reactions. What are those and how can one �see� them in experiment? Case studies to be presented are H2 cleavage and CO2 capture by representative FLP, i.e. a phosphine/borane combination tBu3P / B(C6F5)3. Key point of our work is the time-dependent approach to the mechanisms of chemical reactions involving FLPs � a combination of state-of-the-art Born-Oppenheimer molecular dynamics (BOMD) simulations at finite (non-zero) temperature with exploration of the multidimensional potential energy surfaces (PESs) describing interacting reactants. With such a hybrid approach and with the solute-solvent cluster simulating effects arising from explicit solvent, we have found first indications that molecular dynamics effects might have experimentally verifiable implications in FLP reactions. Major effect arises due to inherent characteristics of co-reactants in the reacting complexes of the type LB---X---LA where the co-reactant X is much lighter than both of the Lewis acid/base-counterparts, i.e. LB and LA, and when interactions between co-reactants take place over relatively large distances (at or slightly below the van der Waals limit). Thus, the separation of timescales on nuclear motion arises at multiple levels in such systems and that makes the dynamical picture of chemical step look very different from the portrayal made with the transition state theory (TST). While disclosure of the non-TST aspects of FLP reactions will be of interest for theoretician, actual predictions of the dynamical theory of FLP reactivity (which will be presented as well) should be of vivid interest for experimentalists.

What are microscopic origins and implications of the molecular dynamics effects in the reaction mechanisms of "frustrated" Lewis acid/Lewis base chemical reactions? First results from case studies of H<sub>2</sub> cleavage and CO<sub>2</sub> capture by the "frustrated" Lewis pairs (FLPs)

248th National Meeting (2014)

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What are microscopic origins and implications of the molecular dynamics effects in the reaction mechanisms of "frustrated" Lewis acid/Lewis base chemical reactions? First results from case studies of H2 cleavage and CO2 capture by the "frustrated" Lewis pairs (FLPs)

What are microscopic origins and implications of the molecular dynamics effects in the reaction mechanisms of "frustrated" Lewis acid/Lewis base chemical reactions? First results from case studies of H₂ cleavage and CO₂ capture by the "frustrated" Lewis pairs (FLPs)