2019 AIChE Annual Meeting

(291g) Solvent Reaction Coordinate for an SN2 Reaction

Authors

Christian Leitold - Presenter, University of Vienna
Marcel D. Baer, Pacific Northwest National Laboratory
Christopher J. Mundy, Pacific Northwest National Laboratory
Gregory Schenter, Pacific Northwest National Laboratory
Baron Peters, University of Iliinois
We study the prototypical SN2 reaction Cl- + CH3Cl → CH3Cl + Cl- in water using QM/MM computer simulations with transition path sampling [1] and inertial likelihood maximization [2]. We have identified a new solvent coordinate that improves upon the original solute-only atom-exchange coordinate used in the classic analysis by Chandrasekhar et al. [3]. The new solvent coordinate quantifies instantaneous solvent induced polarization relative to equilibrium charge density at each point along the reaction pathway. We will present free energy surfaces, transmission coefficients, and a committor test for a selection of solute and solvent coordinates.

[1] P. G. Bolhuis, D. Chandler, C. Dellago, and P. L. Geissler, Ann. Rev. Phys. Chem. 53, 291 (2002).

[2] B. Peters, Chem. Phys. Lett. 554, 248 (2012).

[3] J. Chandrasekhar, S. F. Smith, and W. L. Jorgensen, J. Am. Chem. Soc. 107, 154 (1985).