DFT Research on the Dehydroxylation Reaction of Pyrophyllite 2. Characterization of Reactants, Intermediates, And Transition States along the Reaction Path Molina Montes, María Ester Donadio, Davide Hernández Laguna, Alfonso Sainz Díaz, Claro Ignacio We delineate the dehydroxylation reaction of pyrophyllite in detail by localizing the complete reaction path on the free energy surface obtained previously by Car−Parrinello molecular dynamics and the implemented metadynamics algorithm (Molina-Montes et al. J. Phys. Chem. B2008, 112, 7051). All intermediates were identified, and a transition state search was also undertaken with the PRFO algorithm. The characterization of this reaction and the atomic rearrangement in the intermediates and products at quantum mechanical level were performed for the two reaction paths found previously: (i) direct dehydroxylation through the octahedral hole (cross mechanism) or between contiguous hydroxyl groups (on-site mechanism) and (ii) two-step dehydroxylation assisted by apical oxygens for each of the two steps. New intermediates were found and determined structurally. The structural variations found for all intermediates and transition states are in agreement with experimental results. The formation of these structures indicates that the dehydroxylation process is much more complex than a first-order reaction and can explain the wide range of temperatures for completing the reaction, and these results can be extrapolated to the dehydroxylation of other dioctahedral 2:1 phyllosilicates. 2024-02-12T08:16:32Z 2024-02-12T08:16:32Z 2008-06-19 info:eu-repo/semantics/article Journal of Physical Chemistry A 112(28): 6373-6383 (2008) https://hdl.handle.net/10481/88983 10.1021/jp8010876 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess Attribution-NonCommercial-NoDerivatives 4.0 Internacional American Chemical Society