Materials with singlet oxygen responsive energy transfer and highly substituted polycyclic acenes

This dissertation reports details about in the design, synthesis, and characterization of a novel acene-containing conjugated polymer-based 1O2 sensing system with ratiometric photoluminescent response and the in-depth studies in the structure-property relation in highly substituted acenes.;Chapter One describes the design, synthesis, characterization and performance testing of the acene-linked conjugated polymers responsive to 1O 2 via energy transfer. This type of materials demonstrates ratiometric photoluminescence response upon exposure to photogenerated 1O2, and this chemosensing system is inherent of internal referencing significantly improving the quantitative analysis. Our attempts to acquire the water-compatibility of the acene-containing 1O 2-responsive materials are also depicted.;Chapter Two focuses on the structure, photophysics, and photoxidation of highly substituted diethynyltetracenes. Here, the new tetracene derivatives demonstrate bathochromic photoluminescence emission in comparison to pentacene and maintain suitable reactivity with 1O2 allowing reliable operation under regular laboratory condition. In addition, the highly regioselective photochromism in the substituted diethynyltetracenes and our attempts to prepare acenes with stoichiometric photochromism are also described.;Chapter Three presents a new chemical strategy in stabilizing pentacene combining both electronic and steric effects. A series of unsymmetrically substituted pentacene derivatives were prepared by selective nucleophilic addition. The electronic stabilization effect derived from the phenylethynyl group and the steric effect originated from the various alkyl groups were elucidated in great details.;Chapter Four describes the synthesis and systematic study of substituted acenes that have differences in conjugation both along their long axis (by the number of fused benzene or thiophene rings) and short axis (by the number of fused arylethynyl substituents). Systematic analyses of data obtained using absorbance and fluorescence spectroscopies, cyclic voltammetry, and DFT calculations reveal clear correlation between the common structural perturbations to acene structure with the key parameters such as band gap, frontier molecular orbital energies, and reactivity with 1O2.