Synthesis and properties of conjugated organometallic materials based on multi-metallic tungsten-alkylidyne and tungsten-butadiyne building blocks.

摘要

Many exciting organometallic polymers with good applications in electronic and optical materials have been prepared and studied in the past thirty years. However, these are still some issues keep unaddressed in this field: most reported organometallic polymers either lack the high degree of pi-electron delocalization responsible for the interesting physical properties or have the narrow range of functionalization possible at the metal. This thesis aims to develop a conjugated organometallic system with flexibility of choosing different ligands and transition metals to optimize material's properties.; In Chapter 2 and 3, we have focused on the synthesis and property (optical, electrical) study of symmetric and unsymmetrical multi-metallic building blocks of the type C6R6-m{lcub}CWL4Cl{rcub}m (m = 1, 2, 3; R = H, F) and C6H6-m-n {lcub}CWL4Cl{rcub} m(CCH)n (m = 1 or 2; n = 2 or 1). These compounds show reversible redox property and visible light absorption and emission. At the same time, from synthesis point of view, they are readily extended into polymeric materials. All these d2 neutral building blocks can be chemically oxidized into d1 ions. These ions' magnetic properties are discussed in Chapter 6.; Chapter 4 is the application of symmetric building block to prepare conjugated organometallic polymer. This polymer absorbs visible light and exists as a glassy film. Solution and solid state (film) electronic absorption studies suggest this material's backbone is prevented from the inter chain pi/pi interactions by bulky depe ligands and long alkyl chains on the benzene ring.; A new type of C2-bridged dimetallic building blocks with short metal-metal inter distance (∼5A) have been synthesized (Chapter 5). Materials prepared from these building blocks exhibit special properties resulting from the strong metal-metal couplings. These building blocks are the start point to prepare metallopolyynes.; Transition metal complex's physical properties are closely related to their structures. Molecular orbital diagrams have been used in each chapter to predict and explain material's optical and electrical behaviors.