This thesis describes applications in co-crystal reactivity, structure determination, and mechanochemical preparation. We also investigate the solution-phase reactivities of products derived from a template-directed synthesis. Specifically, we described the acid treatment of an achiral molecular ladder of C2h symmetry composed of five edge-sharing cyclobutane rings, or a [5]-ladderane, with acid results in cis- to trans- isomerization and/or oxidation of end pyridyl groups. Solution NMR spectroscopy and quantum chemical calculations support the isomerization to generate two diastereomers; namely, an achiral and a unique chiral ladderane. The NMR data, however, could not lead to unambiguous configurational assignments of the two isomers. Single-crystal X-ray diffraction was employed to determine each configuration. One isomer readily crystallized as a pure form and X-ray diffraction revealed the molecule as being achiral based on Ci symmetry. The second isomer resisted crystallization under a variety of conditions. Consequently, a strategy based on a co-crystallization was developed to generate single crystals of the second isomer. Co-crystallization of the isomer with a carboxylic acid readily afforded single crystals that confirmed a chiral ladderane based on C2 symmetry. We also demonstrate how the stereochemistry can be retained upon treatment with acid. It will be shown how a monocyclobutane can be used as a model system when investigating the reactivity of the [5]-ladderane.
While investigating the reactivity of a diene diacid we determined that a bicyclobutyl that bears six carboxylic acid groups results from a trimerization of the solid in pure form in the solid state. Powder X-ray diffraction and a co-crystallization are used to solve the structure of the diene and elucidate the stereochemistry of the bicyclobutyl, respectively. Having established the reactivity of the diene diacid we used hydrogen-bond-acceptor (HBA) templates to assemble the diacid in the solid state in a photoactive solid for an intermolecular [2 + 2] photocycloaddition as well as a photostable solid. To enhance strategies to generate stereocontrolled products derived from reactive co-crystals mechanochemical methods were applied to eliminate or reduce the solvent used to prepare the co-crystal solids. In particular, we show how supermolecules with olefins organized by hydrogen-bond donor and acceptor templates that react in the solid state rapidly form co-crystals via solvent-free and liquid-assisted grinding.
| Identifer | oai:union.ndltd.org:uiowa.edu/oai:ir.uiowa.edu:etd-2581 |
| Date | 01 July 2011 |
| Creators | Atkinson, Manza Battle Joshua |
| Contributors | MacGillivray, Leonard R. |
| Publisher | University of Iowa |
| Source Sets | University of Iowa |
| Language | English |
| Detected Language | English |
| Type | dissertation |
| Format | application/pdf |
| Source | Theses and Dissertations |
| Rights | Copyright 2011 Manza Battle Joshua Atkinson |
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