Date of Award
Spring 2020
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
School
Polymer Science and Engineering
Committee Chair
Jason D. Azoulay
Committee Chair School
Polymer Science and Engineering
Committee Member 2
Yoan C. Simon
Committee Member 2 School
Polymer Science and Engineering
Committee Member 3
Derek L. Patton
Committee Member 3 School
Polymer Science and Engineering
Committee Member 4
Charles L. McCormick
Committee Member 4 School
Polymer Science and Engineering
Committee Member 5
Robson F. Storey
Committee Member 5 School
Polymer Science and Engineering
Abstract
Soft condensed matter systems based on polymeric semiconductors are the basis for innumerable emerging applications and discovering new phenomena that will enable next-generation (opto)electronic technologies. General issues at the interface of various fields such as chemistry, polymer science and engineering, and condensed matter physics require new classes of materials with infrared (IR) functionality, complex and tunable electronic structures, varying magnitudes of intramolecular electron-electron pairing, cooperative electronic properties based on π-electrons, controlled spin alignments, and interrelated (opto)electronic functionalities. Despite the achievement of significant technological milestones, clear design guidelines by which to control the bandgap at low energies and augment electronic topology in correlated organic materials remain nascent. To address this, we developed modular synthetic approaches through the extension of molecular conjugation via cross-conjugation using exocyclic aryl olefin substituted cyclopentadithiophene donors, in combination with heteroannulated benzothiadiazole acceptor derivatives. Consequently, we established the capability to carefully control the frontier orbital energetics (separation, position, and alignment), co-planarity of the conjugated backbone, intermolecular interactions, electronic structure, and many interrelated chemical, electronic, and structural factors that affect the degree of electronic correlation.
Our approach is unique in that structural modification of a DA architecture, rather than doping, are used to access polymeric materials with ground states that range from aromatic/quinoidal mixed states to open-shell diradicals with high-spin configurations. These weaker intramolecular electron-electron pairings, and novel electronic structures when compared to their closed-shell counterparts impart varying degrees of, and distinct, optical, electronic, spin, magnetic, transient, and multifunctional activities. These studies are the first of their kind that overcome significant and historically rooted challenges associated with high-spin organic materials and open access to a broad variety of technologically relevant applications once thought of as beyond the current scope of functional organic materials systems.
Copyright
London, 2020
Recommended Citation
London, Alex, "Establishing Electronic Structure Control in Open-Shell Donor-Acceptor Conjugated Polymers" (2020). Dissertations. 1786.
https://aquila.usm.edu/dissertations/1786
Included in
Atomic, Molecular and Optical Physics Commons, Condensed Matter Physics Commons, Organic Chemistry Commons, Polymer and Organic Materials Commons, Polymer Chemistry Commons, Semiconductor and Optical Materials Commons