The Synthesis and Reactivity of [PC(sp2)P] Complexes of Iron and Palladium

Doctoral Dissertation
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Abstract

The reactivity and stability of homogenous transition metal catalysts largely depends on the supporting ligand system. Thus, ligand design is a crucial component to reactivity modulation and optimization of catalysts. In particular, the development of ligand systems capable of participating in metal ligand cooperativity (MLC) has become a popular area of research in the organometallic community. Complexes of this nature promote participation from the supporting ligand and the metal center throughout a chemical process. Credited for their tunability, tridentate, chelating pincer ligands are well-known for their ability to participate in MLC-type reactivity on a variety of different metal centers. More specifically, transition metal carbenes bearing the [PC(sp2)P] pincer framework exhibit unique reactivity, including cooperative 1,2-additions across the M-Ccarbene bond when treated with polar substrates.

This work in mind, efforts towards expanding the [PC(sp2)P] ligand system to an iron metal center were explored and the optimal synthetic route was discovered. Reactivity studies of the resulting[{PC(sp2)P}Fe(PMe3)(N2)] complex with styrene and select alkynes were investigated. The reactivity displayed in the presence of substrates containing π character is not only novel to the reactivity exhibited by other [PC(sp2)P] complexes, but also, all previously synthesized iron carbene complexes.

Furthermore, the Iluc lab has extensively studied the reactivity of a nucleophilic palladium(II) carbene complex, [{PC(sp2)P}Pd(PMe3)]. As a continuation of this work, [{PC(sp2)P}Pd(PMe3)] was treated with H2O to further elucidate its small molecule activation competencies. Results indicated that the second activation of water proceeded through µ-oxo species and prompted the synthesis of a µ-sulfide dimer through treatment of the palladium carbene with H2S. Additional work with [{PC(sp2)P}Pd(PMe3)] focused on the ancillary ligands effect on reactivity and stability of the 4-coordinate carbene system.

Attributes

Attribute NameValues
Author Melissa R. Hoffbauer
Contributor Vlad M. Iluc, Research Director
Degree Level Doctoral Dissertation
Degree Discipline Chemistry and Biochemistry
Degree Name Doctor of Philosophy
Banner Code
  • PHD-CHEM

Defense Date
  • 2019-06-17

Submission Date 2019-06-24
Record Visibility and Access Public
Content License
  • All rights reserved

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