Browsing by Subject "Tetrathiafulvalene"

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Extension of tetrathiafulvalene conjugation through pyrrollic-based dyes : ExTTF porphyrin and ExTTF BODIPY
(2013-12) Bill, Nathaniel Lloyd; Sessler, Jonathan L.
The research and development of organic electron donors is essential in the discovery of photodynamic therapy photosensitizers and catalysts, as well as in the fabrication of organic-based electronic devices. Recently, [pi]-extended tetrathiafulvalenes (exTTFs) have emerged as important organic donors due to their superb electronic properties. However, in general, exTTFs lack significant absorption in the visible and near-infrared portions of the electromagnetic spectrum, thereby limiting their utility. This doctoral dissertation depicts the author's efforts to address this inherent drawback of exTTFs by extending the electronic conjugation of tetrathiafulvalene moieties through pyrrole-based chromophores. The reported findings describe the design, synthesis, properties and potential applications of exTTFs with greatly enhanced absorption profiles. The first Chapter provides a brief historical overview on the history and development of [pi]-extended tetrathiafulvalenes. The various conjugated linkers utilized in exTTF systems are reviewed. In the latter part of the Chapter, emphasis is given to the applications in which exTTFs find use. Chapter 2, as the major focus of the dissertation, details the synthesis and characteristics of a quinoidal porphyrin-bridged exTTF, termed MTTFP. Several metalated complexes, including the Zn, Co, Cu, and Ni derivatives of MTTFP are reported. Additionally, the electrochemical, photophysical, and structural properties of MTTFPs are discussed. We also detail our efforts to synthesize and characterize both the one- and two-electron oxidized forms of MTTFPs. Finally, we discuss our efforts to reversibly switch thermodynamic electron transfer from ZnTTFP to Li@C₆₀ through coordination of axial ligands. Chapter 3 describes the formation of a 2:1 supramolecular ionic porphyrin complex between the two-electron oxidized form of ZnTTFP and a tetranionic sulfonated porphyrin. The association constants and the X-ray crystal structure of the complex are reported. A brief discussion outlining the photophysical characteristics (performed in Prof. Shunichi Fukuzumi and Prof. Dongho Kim's group) of the porphyrin donor-acceptor complexes are included. Chapter 4 details the synthesis, photophysical properties, and spectroelectrochemistry of a difluoroboradiazaindacene (BODIPY) bridged exTTF. This compound is referred to as ex-BODIPY. A singlet oxygen generation study provides initial evidence that ex-BODIPY could potentially serve as a photosensitizer. All of the experimental procedures, characterization data, and X-ray crystallographic data tables are reported in Chapter 5.
Tetrathiafulvalene as a molecular building block in various systems
(2015-12) Leem, Soojung Clara; Sessler, Jonathan L.; Anslyn, Eric V
Tetrathiafulvalene (TTF), a classic electron rich donor system, has received renewed attention within the supramolecular and complex ligand chemical communities. As the result of recent synthetic advances, TTF and its derivatives have been incorporated into many complex receptor systems that have been explored as binding agents, sensors, and electron transfer models. In this thesis, the synthesis and the attempted use of TTF moieties in the construction of systems that could see a variety of applications will be described. In the first chapter, a brief overview of the theoretical and historical background of TTF is given with the focus on the redox properties of TTF. The second chapter details the design of, and synthetic attempts to prepare a new TTF-based anion receptor. This latter system was designed to allow a well-recognized anion binding motif to be attached to a TTF core. However, the desired target was not obtained. The third chapter describes the author’s contribution to the development of a self-assembled system comprised of a TTF-substituted macrocycle and a functionalized fullerene. In this ensemble, two heteroditopic monomers combine to create a chemically and electrochemically responsive supramolecular oligomeric product.
Tetrathiafulvalene Schiff-base ligands and anion receptors
(2012-12) Bejger, Christopher Michael; Sessler, Jonathan L.
Over the last decade, the classic organic donor tetrathiafulvalene (TTF) has emerged as an important functionality in supramolecular systems and complex ligand chemistry. Due to synthetic advances, TTF is no longer a moiety strictly limited to the area of charge transfer salts in material science. In fact, many complex systems incorporating the electron rich donor system are known. More can be imagined. This doctoral dissertation describes the author's journey in designing, synthesizing, and studying various compounds in which the TTF moiety serves a practical purpose, oftentimes giving known molecules new functions. The reported findings have led to a greater understanding of anion binding effects on TTF-containing anion receptors, the use of transition metals to pre-organize [pi]-faces for through-space donor-acceptor interactions, and the introduction of actinide species to tetrathiafulvalene ligands. The first Chapter provides a brief introduction and a short history of TTF chemistry. It also provides an overview describing the fundamental properties of TTF compounds, including TTF dimeric behavior and redox properties. Chapter 2, as the major focus of this dissertation, details the use of a flexible TTF-modified macrocyclic ligand, which upon metallation can effectively preorganize two TTF units to interact when oxidized. Specifically, a new way to stabilize the through-space mixed-valence TTF dimer, in which a transition metal can affect the degree of interaction between the two TTF units, is described. The mixed-valence TTF species in question could see use as components in molecular machines and could play an important role as molecular organic conductors, and discussions along these lines are included in this chapter. These mixed valence complexes were investigated by spectroscopic (¹H-NMR, UV-Vis NIR titrations, and EPR analysis) and X-ray single crystallographic analyses involving both the neutral and oxidized products. Chapter 3 introduces the synthesis, characterization, and electrochemistry of the first TTF-ligand to form a complex with an actinide cation. Chapter 4 details the synthesis, binding studies and X-ray single crystallographic analyses of a TTF-based electrochemical sensor for dihydrogen phosphate anion detection. Experimental procedures and characterization data are reported in Chapter 5.