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Synthesis and electronic properties of metallocene-vinylene oligomers and ferrocenyl phenylene-vinylene oligomers
Abstract
This dissertation presents the study of metallocene-vinylene (McV) oligomers and ferrocenyl phenylene-vinylene oligomers (FcPV). They have been synthesized via palladium catalyzed coupling reaction and volatile alkene metathesis (VAM) reaction. Redox potentials and spectroscopic data with their structures have been investigated to understand electron transfer (ET) properties related to the structural nature of its bridging group. Iron, ruthenium, and osmium McV dimers and their heterometallic counterparts including diferrocenyl-butadiene and -hexatriene derivatives were synthesized via palladium catalyzed vinylferrocenylation and VAM. The crystal structure of trans- and cis-1,2-diferrocenylethylene have been determined. The monocations of ferrocenyl dimers linked by a vinyl-, butadiene-, and hexatriene, bridge are moderately localized class II ions based on their intervalence transfer band analysis and redox potential data. McV trimers and tetramers have been prepared via above two methods. Useful precursors to polymers such as 1,2-divinyl-ferrocenyl-vinylene dimers and 1,3-divinyl-ferrocenyl-vinylene trimers have been synthesized by VAM. Evidence that long-range effects may exist in related polymers is found in the redox behavior of ferrocenyl-vinylene trimers. (E)-Ferrocenylstyrenes, (E,E)-1-ferrocenyl-4-aryl-1,3-butadienes, phenylene-vinylene oligomers including phenylene-vinylene precursors have been synthesized in good yields with high regio- and stereoselectivity via palladium catalyzed arylation. The relatively high Hammett $\rho$-values for styryl (r = 1.44) or arylbutadiene (r = 0.93) substituents have been obtained. The structure of (E)-$\beta$-ferrocenyl-p-fluorostyrene has been determined. In addition, the redox potential of ferrocene of phenylene-vinylene dimer in a remote distance (11 C-C bonds) is influenced by a substituent (NO$\sb2$ or NH$\sb2$). The pH dependence of the redox properties, UV-spectra and solvatochromic effects for (E)-1 ferrocenyl-2-(4-pyridine)ethene and (E,E)-$\beta$-ferrocenyl-$\beta \sp{\prime}$-(4-pyridinyl)-p-divinylbenzene with their corresponding salts are discovered. Ferrocenyl-phenylene-vinylene-thiol oligomers have been developed as a molecular wire.
Subject Area
Chemistry|Organic chemistry
Recommended Citation
Lee, Hookun, "Synthesis and electronic properties of metallocene-vinylene oligomers and ferrocenyl phenylene-vinylene oligomers" (1996). ETD collection for University of Nebraska-Lincoln. AAI9708071.
https://digitalcommons.unl.edu/dissertations/AAI9708071