Date of Award

1-1-2012

Document Type

Campus Access Dissertation

Department

Chemistry and Biochemistry

Sub-Department

Chemistry

First Advisor

zur Loye, Hans-Conrad

Abstract

Materials discovery is the driving force behind the research presented herein. Basic research has been conducted in order to obtain a better understanding of coordination chemistry and structural outcomes, particularly within the area of trivalent lanthanides. Discovering new materials is one route to further advancement of technology; another one is the focus on incremental changes to already existing materials. Often the building blocks of a compound are chosen in an effort to synthesize a material that makes use of the properties of each individual component and may result in a better, more robust, applicable material. The combination of organic and inorganic components for the synthesis of novel materials with potential applications such as scintillation photoluminescence, catalysis, and gas storage are the focus of the research presented herein.

The first part focuses on lanthanide organic hybrid materials, where the synthesis of a new family of potential scintillating materials was undertaken and yielded improved understanding of the control that can be achieved over the topological structure of these materials by controlling the coordinating crystallization solvents. This research has led to the synthesis of an array of unique motifs, ranging from dimeric complexes, tetrameric complexes, to 1-D chains, and most intriguing of all, catenated tetradecanuclear rings. These rings represent the largest lanthanide rings synthesized to date, the next largest multinuclear rings, until now, were dodecanuclear complexes of alkoxides. From a basic research standpoint this is an exciting new development in lanthanide coordination chemistry and illustrates the importance of steric effects upon a system. These complexes are potential scintillators, supported by their luminescence and measurements of similar compounds that demonstrate surprising scintillation efficiencies. In the second part, other hybrid materials that have also been prepared are discussed, including the synthesis of a polyoxometallate compound (POM) containing a typical Keggin ion, which is charge-balanced via protonated organic ligands. POMs are one of the most studied inorganic clusters owing to their potential catalytic capabilities. A third part concerns a pseudo hybrid material consisting of boron, a metalloid, and a polymeric network, which includes a site of contortion, provided by the incorporation of a disulfide linkage and polymerized through boronate ester linkages. Tuning of this disulfide-linked polymer of intrinsic microporosity has the potential to lead to a dynamic material that may have gas sorption properties.

The fourth part describes research in which the goal was to synthesize novel metal organic frameworks (MOFs) for solid state lighting applications via the synthesis of long, rigid, highly conjugated ligands. The successful synthesis of these ligands and optimization of the reaction conditions through the use of cyano derivatives as intermediates was discovered. Subsequent incorporation into coordination polymers with the transition elements was unsuccessful. This is believed to be the case due to the rigidity of the ligands and their inability to be flexible enough to successfully coordinate to a metal cation in a crystalline form.

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