New Organic and Organometallic Platforms for Luminescence and Catalysis Applications

This dissertation describes the development of organometallic compounds, including cyclometalated platinum and iridium complexes and iridium pincer complexes, and organic chromophores, applied to dehydrogenation of alkanes, Lewis-acid-modulated luminescence, and ratiometric O2 sensing. Chapter 1 describes a series of cyclometalated platinum complexes with two different fluorinated β-diketiminate (NacNac) ligands, with the nuclearity of the product depending on the temperature of the reaction. The two types of complexes are characterized by X-ray crystallography, UV-vis absorption and emission spectroscopy, and by cyclic voltammetry, which shows a reversible reduction at mild potentials. All of these properties are suggested to involve NacNac-centered frontier orbitals. Chapter 2 describes two pyridyl-substituted BODIPY compounds and one aza-BODIPY, which can interact with the strong Lewis acid B(C6F5)3. The interactions of BODIPYs with borane Lewis acids induce significant changes in the photophysical properties of these chromophoric molecules. Chapter 3 introduces a new class of ratiometric O2 sensors for hypoxic environments. Two-component structures composed of phosphorescent cyclometalated Ir(III) complexes and the well-known organic fluorophore BODIPY exhibit dual emission, with significant phosphorescence from the iridium site and fluorescence from the BODIPY, and thus function as ratiometric oxygen sensors. Finally, Chapter 4 describes the synthesis of two type iridium pincer complexes (CCC- and CNC types) as precatalysts for the dehydrogenation of cyclooctane.