Harnessing the potential of coinage metal redox intermediates

First row transition metal complexes have found a wide range of utility in many applications, from quantum information science to catalysis and photosensitization. The push to substitute high-performing non-earth abundant metals with Fe, Ni, Cu and Co has allowed for incredible advancements in this field. Among the many applications and accessible transition metal complexes, this document will focus on the development of several cyclic and acyclic pyridine-based ligand frameworks to pursue catalytic and photocatalytic reactivity of nickel and copper. The first 4 chapters focus on the use of bi- tri- and tetradentate pyridinophane ligands and their immense structural tunability. Results indicate that these ligand frameworks can be significantly tuned for both high and low-valent Ni, allowing for diverse reactivity. While tetradentate pyridinophanes are well equipped for high-valent Ni species, their steric congestion makes them less ideal for reactivity. Results show that both bi- and tridentate pyridinophanes are capable of accessing high and low valent Ni, with tridentate ligands yielding the highest stability. Experimental and computational results reveal the criticality of axial ligand binding interactions in complex stability. This work also reveals that recently developed tridentate pyridinophane ligands are capable of facilitating photocatalytic C–O cross-coupling in extremely high yields. Both static and transient absorbance spectroscopy suggests that the high performance is attributed to a pre-irradiation substrate binding process which drastically alters the absorption of the sample and causes distinct excitation wavelength dependent behavior. Finally, the tridentate ligand frameworks show promising results in the field of small molecule quantum computing devices. The ligand’s ability to make NiII EPR addressable while still maintaining adequate field strength reveals the perfect combination of traits for molecular qubit design.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Holm, Annika

Contributors dc:contributor

• Mirica, Liviu M.
• Mirica, Liviu M
• Vura-Weis, Joshua
• Jackson, Nicholas E
• Fataftah, Majed S.

• Transition Metal Complexes
• Inorganic
• Catalysis
• Nickel
• Copper
• Photoredox Catalysis
• Photosensitizer
• Tict
• Earth-abundant
• Qubits
• Pyridinophane

Statement dc:rights

• ©2025 [Annika Rachel Holm] All rights reserved, including the right to reproduce this dissertation or portions thereof in any form whatsoever, except as permitted by United State copyright law. Reprinted with permission from J. Phys. Chem. A. 2023, 127, 37, 7747–7755. Copyright 2023 Retained by the Authors

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/130107

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F130107