Chemistry and Chemical Biology ETDs

Publication Date

Spring 4-14-2022

Abstract

Within this dissertation, photochemical systems that bear significance to next-generation photonic materials and devices are explored. Notable advances in the design, synthesis, and characterization of three distinct groups of photoactive molecules are achieved through molecular design and spectroscopic analysis. First, novel ruthenium sulfoxide complexes bearing substituted phosphine ligands are found to provide extraordinary control over photoisomerization quantum yields. A comparison of these complexes reveals ground-state characteristics that are instrumental in this reactivity, while a novel spectroscopic technique provides rare structural evidence for an O-bonded metastable isomer. Ruthenium complexes bearing chelating carbene-sulfoxide ligands rapidly thermally revert from the O-bonded metastable isomer to the S-bonded isomer in the ground state and are resistant to photosubstitution, even in strong donor solvents like acetonitrile. Second, the photophysics of pyrene sulfoxide compounds with substituted alkyl and aryl substituents are investigated. An excited state pathway is proposed for these compounds that addresses their photochemical response to both changes in solvent and changes in substituent. Third, platinum-containing small molecules with roller-wheel type stacking interactions, which are a promising in bulk heterojunction photovoltaic devices, are developed. Time-resolved absorption and emission spectroscopies are employed to reveal the excited state dynamics of these systems, as well as the role of extended pi-bridges and electron acceptor units. In total, the projects that are covered herein address how molecular engineering can be used to both drastically alter the chemical properties of a system and employ those changes as spectroscopic handles to gain insight about excited state dynamics.

Language

English

Keywords

Photochemistry, Ruthenium, OPV, Pyrene, Sulfoxide, Spectroscopy

Document Type

Dissertation

Degree Name

Chemistry

Level of Degree

Doctoral

Department Name

Department of Chemistry and Chemical Biology

First Committee Member (Chair)

Jeffrey Rack

Second Committee Member

Martin Kirk

Third Committee Member

Alejandro Manjavacas

Fourth Committee Member

Dongchang Chen

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