Open Access Dissertation
Date of Award
H. Bernhard Schlegel
This dissertation covers research performed on applications of electronic structure theory to various fields of chemistry and is divided into eight chapters. Chapters 2 through 4 describe a series of related works which explore applications of excited state electronic structure methods to problems in strong field chemistry. Chapters 5, 6, and 7 discuss the application of electronic structure theory methods to solving problems in inorganic chemistry. Finally, Chapter 8 looks at an application of electronic structure theory to nanomaterials.
Chapter 2 covers the modeling of electron dynamics of butadiene interacting with a short, intense laser pulse in the absence of ionization This chapter lays down the ground work for the following two chapters by examining the effects of basis set size and number of excited states included in the TD-CI simulation on the amount of population transferred from the ground state into the excited states by the interaction with an short, intense, non-resonant laser pulse. This chapter focuses mostly on TD-CI simulations using excited state energies and transition dipole matrices found by wavefunction based methods: TD-HF, TD-CIS, and TD-CIS(D). Chapter 3 expands on the work established in Chapter 2 by examining the excited state populations of butadiene using excitation energies and transition dipoles calculated by time-dependent density functional theory. Several DFT functionals are tested including GGA, meta-GGA, hybrid and long-range corrected functionals. The degree to which excited state energies and transition dipoles contribute to the final populations of the excited states is also examined. Chapter 4 wraps up the series by including ionization using a heuristic ionization model. This chapter examines the strong-field ionization of a series of linear polyenes of increasing length: ethylene, butadiene, hexatriene, and octatetraene. Also tested is the ionization dependence on parameters of the ionization model, basis set size, and number of states included in the simulation.
Chapters 5-7 discuss collaborative works with members of the inorganic division of chemistry at Wayne State University. Chapter 5 describes a study on a chiral pentadenate ligand synthesized by the Kodanko group and the geometrical preference for a single isomer out of five possible isomers. Electronic structure theory indicates that the favored geometry is due to the chiral ligand, which prefers to be in a single conformation in metal complexes due to steric interactions. Chapter 6 covers a paddlewheel dinculear Cu(II) complex synthesized by the Winter group. This complex has the shortest Cu--Cu separation reported to date and electronic structure theory is used to explore the cause of this small separation. A simple model is proposed where the metal separation is governed by twisting of the ligand due to interligand π orbital interactions. Chapter 7 describes work done in collaboration with the Verani group, exploring the redox properties of some five-coordinate Fe(III) complexes.
Chapter 8 sets out to develop an inexpensive model that can be used to optimize guest systems inside single walled nanotubes. The model takes advantage of the highly polarizable nature of nanotubes. The model is calibrated using a simple hydrogen bonded system and comparisons are made to test the reliability of the model.
Sonk, Jason Anthony, "Applications of electronic structure theory to problems in strong-field chemistry, inorganic chemistry, and nanomaterial systems" (2012). Wayne State University Dissertations. Paper 520.