Elucidating the "on water" mechanism in accelerated reactions in water
department or school: Science, Irving K. Barber Faculty of (Okanagan)
department or school: Chemistry, Department of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Romero Montalvo, Eduardo Alejandro
issued: 2023-11-02T20:59:33Z
issued: 2023
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Water as a reaction medium for organic reactions has potential applications in different areas of chemistry. Consequently, aqueous organic chemistry has increasingly become relevant in the past few decades; one of these types of reactions, and the main topic of this thesis, is the “on water” reaction. This reaction involves the increased rate of reactions of selected organic reactions when they occur in the presence of an organic aqueous interface; such an increase in the kinetics of the reaction is relative to the same reaction in solventless or organic solvent conditions. Over the years, some models based on hydrogen bonding, proton transfer and dipole moment have been proposed. Still, there has yet to be a general agreement on the molecular origin of this phenomenon. In this thesis, we explored, through computational methods, the mechanism driving this unusual reactivity. It was found that the accelerated effect observed in “on water” reactions arises from a combination of different effects: hydrogen bonding at the interface stabilizes transition states with respect to pre-reaction complexes, and strong electric fields near the water-oil interface have a dominant effect on the reduction of energy barriers associated with “on water” reactions. Based on these findings, we propose a new mechanism for “on water” reactions. In addition, we present an explanation of the origin of the kinetic isotope effect that “on water” reactions display based on the difference in the macroscopic physical properties between D₂O and H₂O (kH/kD). This thesis offers insights into the still poorly understood chemistry of water in heterogeneous conditions; it provides a rationale for understanding chemical processes occurring near confined or interfacial water. The insights found in this thesis are relevant to other fields of chemistry, such as green chemistry, biochemistry, organic chemistry and atmospheric chemistry.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/86434
note: Elucidating the “On Water”Mechanism in Accelerated Reactionsin WaterbyEduardo Alejandro Romero MontalvoB.Sc. Hons., Universidad Nacional Auto´noma de Me´xico, 2014M.Sc. Hons., Universidad Nacional Auto´noma de Me´xico, 2016A THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFDOCTOR OF PHILOSOPHYinTHE COLLEGE OF GRADUATE STUDIES(Chemistry)THE UNIVERSITY OF BRITISH COLUMBIA(Okanagan)October 2023© Eduardo Alejandro Romero Montalvo, 2023The following individuals certify that they have read, and recommend to the College of GraduateStudies for acceptance, a dissertation entitled:Elucidating the “On Water” Mechanism in Accelerated Reactions in Watersubmitted by Eduardo Alejandro Romero Montalvo in partial fulfilment of the requirementsof the degree of Doctor of Philosophy in Chemistry.Dr. Gino A. DiLabio, University of British ColumbiaSupervisorDr. Kevin M. Smith, University of British ColumbiaSupervisory Committee MemberDr. Robert Godin, University of British ColumbiaSupervisory Committee MemberDr. Jian Liu, University of British ColumbiaUniversity ExaminerDr. Stacey Wetmore, University of LethbridgeExternal ExamineriiAbstractWater as a reaction medium for organic reactions has potential applications in different areas ofchemistry. Consequently, aqueous organic chemistry has increasingly become relevant in the pastfew decades; one of these types of reactions, and the main topic of this thesis, is the “on water”reaction. This reaction involves the increased rate of reactions of selected organic reactions whenthey occur in the presence of an organic aqueous interface; such an increase in the kinetics of thereaction is relative to the same reaction in solventless or organic solvent conditions. Over the years,some models based on hydrogen bonding, proton transfer and dipole moment have been proposed.Still, there has yet to be a general agreement on the molecular origin of this phenomenon. In thisthesis, we explored, through computational methods, the …
has type: Thesis/Dissertation
date issued: 2024-02
is shown at: 10.14288/1.0437519
language: eng
degree discipline: Chemistry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: DiLabio, Gino
type: Text
identifier URI: http://hdl.handle.net/2429/86434