xxi, 294 p. ill. (some col.) A print copy of this title is available through the UO Libraries under the call number: SCIENCE QD403.O23 2008 / Highly conjugated carbon-rich systems have demonstrated many attractive applications for fundamental and materials science applications, including--but not limited to--probes for aromaticity, charge-transfer complexes, conducting/semi-conducting materials, linear/nonlinear optical materials, and solar cells. The bulk of this research has focused on carbon-rich fullerenes, conjugated polymers, or polycyclic aromatic hydrocarbons; however, with recent developments in cross-coupling chemistry, carbon rich chemistry, particularly dehydrobenzo[ n ]annulenes (DBAs), has grown to yield molecules of great diversity and utility. Concurrently, materials based on conjugated heterocycles have been developed and display similar and often enhanced properties to the aforementioned carbon rich systems. The lone pair of the heterocycle often adds additional stability and polarizablity, creating novel and tunable molecules. Assimilating techniques used to produce DBAs with heteroaromatic molecules, our work has afforded a novel class of conjugated macrocycles with the highly tunable optical-electronic properties of a DBA system. That in turn has led to the systematic study of the diverse structure-property relationships of the thiophene/DBA hybrids reported herein. Chapter I details the synthetic advances in the field of DBA chemistry. The first section discusses the methods of synthesis, inter- vs. intra- molecular approaches, while the remaining sections provide current examples of the DBAs reported. Chapter II briefly discuses conjugated thiophene chemistry, then describes the advantages of utilizing planarized thiophenes. Several examples of thiophene macrocycles are reviewed: both planar and nonplanar. Particular attention in the review focuses on synthesis, optical properties, and some redox properties. Chapters III and IV detail the synthesis and analysis of thiophenes locked into [14]- and [15]annulene scaffolds, respectively. The dehydrothieno[14]annulenes (DTAs) and DTA/DBA hybrids of chapter III serve as aromatic probes and show significant tunabilty with respect to the number and orientation of the thiophenes. Chapter IV's dehydrobenzo[15]annulenes, which are comprised of a cross-conjugated system, also display a structure-property relationship where the optical properties encompass a wider dispersion of wavelengths. Chapter IV also explores the incorporation of pyridines and the affects on conjugation. The electronic properties of the macrocycles were explored using NMR, UV-Vis absorption and fluorescence spectroscopy, and electrochemically (cyclic voltammetry). Chapter V is devoted to further functionalization of DTAs through alkylation and further cycliziation to yield planarized terthiophene units. This dissertation includes my previously published and co-authored material. / Adviser: Michael M. Haley

xx, 361 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Highly conjugated carbon-rich molecules have attracted interest in recent years due to unique electronic, optical and materials properties. Carbon networks based upon the phenylacetylene subunit are increasingly recognized as building blocks for a host of sensing and electronics components due to the rigidity and linearity of carbon-carbon triple bonds. Further extending this motif into a macrocycle, generating a dehydrobenzoannulene (DBA), also confers planarity, increasing the à -conjugation and giving rise to enhanced materials behavior. Functionalization of arylacetylenes and DBAs with electron donating and accepting groups manipulates the energetics such that finely-tuned optoetectronic properties can be devised for customized applications, including fluorescent sensor arrays, organic light-emitting diodes, and nonlinear optical materials. Fundamental structure-property relationship studies into certain physical modifications of molecular architecture effects on the photophysics, intramolecular charge transfer (ICT), or complexation properties are of importance in the rational design of the next generation of organic electronics. Chapter I provides a review of recent advances in the field of annulene chemistry. It is organized by cycle type, size, and application within each category. Chapter II describes syntheses and ion responses of an array of donor/acceptor-functionalized arylacetylenes. The independent manipulation of frontier molecular orbital (FMO) energy levels is discussed in relation to a fluorescent switching phenomenon. Chapter III expands this effect to include [15]DBAs. The consequences of incorporating protonatable donor/acceptor groups into a macrocycle, as well as placement of the acceptor nitrogen are examined, and comparison of calculations to experimental results imply generation of transient ICT species with induced FMO localizations. Chapter IV describes the syntheses of acyclic tetrakis(phenylethynyl)benzene (TPEB) and [14]- and [15]DBA systems utilizing fluorinated acceptor groups. Comparisons between these inductive acceptors and earlier resonance acceptors are made, and imply greater stability and processing potential for optoelectronic applications. Chapter V describes a series of bis[18]DBAs functionalized with dibutylamino groups as donors and nitro groups as acceptors. The effects of 2-donor/2-acceptor versus 4-donor/4-acceptor motifs are explored, and trends are identified in the systematic adjustment of the optical band gap that will have important implications for the design of two-photon absorbing materials. This dissertation includes my previously published and co-authored material. / Adviser: Michael M. Haley