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Synthesis of precursors to and spectroscopic characterization of highly unsaturated carbenes and diradicals and development and implementation of a web-based stereochemistry tutorial

Posted on:2011-07-27Degree:Ph.DType:Thesis
University:The University of Wisconsin - MadisonCandidate:Burrmann, Nicola JeanFull Text:PDF
GTID:2467390011471671Subject:Chemistry
Abstract/Summary:
A variety of substituted diynols, diynals, and diynones have been prepared en route to the synthesis of precursors to dialkynyl carbenes (R1–C≡C–C–C≡C–R 2). In light of the unique reactivity associated with these simple systems, several strategies were required to assemble the carbon backbones (Chapter I).;Tosylhydrazone and trisylhydrazone precursors to 2-diazo-3-pentyne ( 1), 2-diazo-3-butyne (2), and Idiazo-2-butyne ( 3) were synthesized and then converted into their respective diazo compounds. Various attempts to study these diazo compounds using matrix isolation IR and EPR spectroscopy were made and proved to be unsuccessful. Computations were done to characterize the C5H6 potential energy surface, as well as to determine the IR vibrational frequencies of the isomers on this surface (Chapter 2).;A web-based Stereochemistry Tutorial that details the core definitions and structural representations relevant to organic stereochemistry was designed and implemented into several introductory-level organic chemistry classes. This tutorial also allows for students to select their preferred structural representation and method for making stereochemical comparisons between molecules. The tutorial was evaluated, either qualitatively, quantitatively, or both, by students in three different introductory organic chemistry courses at the University of Wisconsin—Madison. The data show that students did use a variety of different methods for making stereochemical comparisons between molecules, and that prior exposure to lectures on stereochemistry by the course professor strongly influenced these choices. Furthermore, the level of improvement in stereochemical knowledge as a result of using only the tutorial was comparable to, or higher than, that achieved by students who were only exposed to lectures by the course professor, regardless of the method chosen for making stereochemical comparisons between molecules (Chapter 3).
Keywords/Search Tags:Making stereochemical comparisons between molecules, Precursors, Tutorial, Stereochemistry
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