RT info:eu-repo/semantics/doctoralThesis
T1 Análisis de los procesos de intercambio arilo/haluro en AuIII y revisión de los conceptos retrodonación e influencia trans en sistemas MIIICp*
A1 Fernández Moyano, Sara
A2 Universidad de Valladolid. Escuela de Doctorado
K1 Catálisis
K1 Catalysis
K1 Catálisis
K1 Mechanisms
K1 Mecanismos
K1 23 Química
AB Current chemical research increasingly requires the appropriate and complementary use of mixed methodologies, both experimental and theoretical. In this doctoral thesis several studies have been carried out applying different methodologies to obtain a deep understanding of the proposed chemical problems. In the first chapter, a structural analysis was performed from geometries optimized by computational calculations and X-Ray structures of the synthesized complexes to rationalize the variations in M-CCp* and CCp*-CCp* bond distances in Cp*MIII complexes (M = Rh, Ir). This study allowed us to support the hypothesis that the Cp* group responds to variations in the electronic requirements of the metal center, which has allowed us to establish a series of trans influence of the different ligands used.On the other hand, theoretical calculations have allowed us to carry out an orbital analysis to reveal the presence of relevant interactions, previously ignored. In particular, NBO (Natural Bonding Orbitals) studies allow us to identify (and quantify) lateral donations from the Cp* group to the empty orbitals of carbonyl and cyanide ligands (CO and CN-), which behave as π-acceptors. Such usually ignored donations add to the classical retrodonation by the metal and must be considered in this type of systems.The second chapter is largely based on mechanistic studies for which nuclear magnetic resonance (NMR) has undoubtedly been the most important experimental technique, applied beyond its routine use as a method of characterization of organometallic compounds. The vast majority of the synthesized complexes present fluorinated aryls in their structures, which allows a follow-up by 19F NMR, as well as elucidating the identity of the different species in complicated reaction mixtures, for example, the [AuIIIArF3(OH2)] species.Other technique used in this chapter to rationalize certain a priori non-trivial observed kinetic behaviors is microkinetic modeling, using COPASI software, which allows kinetic simulations and multiple nonlinear adjustments to be carried out.  This type of tool works on kinetic models and allows making mechanistic proposals capable of explaining the observed experimental behavior. In this case X-ray diffraction, in addition to serving as a characterization technique, has allowed us in this case to identify species from complicated reaction mixtures, as well as to detect species invisible to other techniques, including the (NBu4)[AuI2] complex. Once again, the ability of theoretical calculations to visualize species impossible to detect experimentally, such as high-energy intermediates and transition states, stands out. Both thermodynamic and kinetic data can be obtained from them, which are subsequently used as a reference for kinetic simulations or as support for mechanistic proposals, even allowing the study of reactions that do not occur in order to rationalize complex experimental observations, for example, the transition state responsible for a hypothetical ArF-ArF coupling (the reductive elimination Rf-I is kinetically more accessible).In summary, we could say that the main objective of this thesis (and its main thread) is the presentation of strategies to face mechanistic investigations, or other kind of studies (interaction analysis...), synergistically combining different experimental and computational tools.
YR 2022
FD 2022
LK https://uvadoc.uva.es/handle/10324/59761
UL https://uvadoc.uva.es/handle/10324/59761
LA spa
NO Escuela de Doctorado
DS UVaDOC
RD 17-jul-2024