Browsing by Subject "Organomercury"
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Item One-electron oxidations and reductions of organomercurials and organotins(Texas Tech University, 1995-05) Do, Sang RokSingle ectron-transfer (SET) oxidations of alkylmetals in the lead, mercuiy and tin series have been studied extensively by Kochi and co-workers. Substantial evidence for both iimer and outer electron transfer in oxidations by, for example, hexachlo[oiridate(IV) and tris(l,10-phenanthroline)iron(III) complexes, leading to the fcvmation of alkyl radicals, has been provided. Recently, Shine and co-workers have found evidence for SET in reactions of thianthrene cation radical perchlorate fTh'''*G04~) with aiyllithiums, aryl- and alkyl Grignard reagents,2 dialkylmercurials, and tetraalkyl- and tetraaiyltins.^ In contrast, it was also found from more recent work that reactions of diarylmercurials with Th'*'*Q04~ showed the lack of signs of radical formation through SET. The objective of this study was to characterize the chemistry of electron transfer by the reaction of cation radicals of tris(p-bromophenyl)mine, tris(p-chlorophenyl)amine and tris(p-cart>omethoxyphenyl)amine with symmetrical diaiylmercurials (Ar^Hg), in which Ar = phenyl, o-tolyl, p-tolyl, o-anisyl, p-anisyl and o-allyloxyphenyl. In the reactions of tris(l,10-phenanthroline)iron(III) complex with diarylmercurials such as diphenylmercury, di(o-alIyloxyphenyl)mercuiy and di(2-allyloxy-4,5-dimethylphenyl)mercury, the object was to find if one-electron oxidation by a transition metal complex could generate aryl radicals, and whether the aryl radicals could be trapped or scavenged. The purpose of studying the reactions of tetranitromethane with diaryhnercurials was to probe the validity of the aiyl radical mechanism which had been proposed earlier for the formation of aromatic hydrocarbons in the reactions of tetranitromethane and halogenotrinitromethanes with diphenyl- and dimesitylmercury) and with tetraphenyltin.Item Synthesis and material properties of supramolecules containing fluorinated organomercurials(2009-05-15) Taylor, Thomas JacksonThis dissertation details the synthesis and analysis of novel supramolecular species that feature simple fluorinated organomercurials, such as trimeric perfluoroortho- phenylene mercury ([o-C6F4Hg]3). These organomercurials can complex a variety of unsaturated substrates including arenes and alkynes. The major emphasis was on developing molecular architectures that are held together in part by secondary Hg-Calkyne interactions. Diphenylpolyynes, hydrocarbons featuring extended regions of unsaturation, were found to complex with [o-C6F4Hg]3 in a series of adducts. While the internal structures of the hydrocarbons themselves were found to be basically unaltered, within the crystals the polyynes were physically separated from one another by intervening molecules of [o-C6F4Hg]3, preventing them from cross-linking. This leads to a substantial stabilizing effect, for example [o-C6F4Hg]3 and Ph(CC)4Ph form a 2:1 adduct that is stable at temperatures up to 120 ?C above the pure hydrocarbon. Adducts of [o-C6F4Hg]3 and molecules containing a 1,3,5-triethynyl benzene core display a variety of novel properties. 1,3,5-tris(trimethylsilylethynyl) benzene forms binary supramolecular stacks with [o-C6F4Hg]3. The structure also displays large cylindrical 1-dimensional cavities. These cavities are lined with non-polar groups, have an internal diameter of 6.2 ?, and remain stable in the absence of guests. The compound readily interacts with and reversibly adsorbs simple alkanes. 1,3,5-tris(phenylethynyl) benzene forms similar stacks with [o-C6F4Hg]3, albeit without the cavities. Upon irradiation with visible and ultraviolet light, this adduct emits a long-lived emission that was hitherto unreported. From computer calculations and lifetime measurements, it appears this radiation is the phosphorescence of the pure hydrocarbon. Intensive structural studies have also been performed on adducts containing polyaromatic compounds, including phenanthrene, and the organomercurials [o- C6F4Hg]3, pentafluorophenyl mercury chloride and bromide. These experiments were performed to determine if Lewis acid-p complexes could be made with monofunctional mercury compounds. Polyaromatic hydrocarbons, such as phenanthrene and diphenylacetylene, were used as the substrates for these investigations. While all the mercurials formed adducts with the substrates, the photophysical measurements were not uniform and indicate that [o-C6F4Hg]3 has a stronger heavy-atom effect because of the cooperativity of the three mercury atoms.