Item type:Thesis, Open Access

Kristallstruktur eines aromatischen Tetraboran(4)-Dianions, ein nichtklassisches Triboracyclobutan und ein Borylboratiren mit sehr starker C-B-Hyperkonjugation

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Philipps-Universität Marburg

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Abstract

So far unknown two-electron aromatics with classical and nonclassical sigma skeletons are acquired experimentally in this dissertation (PhD thesis). By synthesis and X-ray structural analysis of the first dianion of a tetraboracyclobutane (tetaraborane(4)), the series of puckered four membered two-electron aromatics with classical sigma skeletons was completed. Prerequisite for this was the development (design) of perparative route to the precursor, which was accessible only in very low yields (0.5%) before. A new planar two-electron aromatic tetraboracyclobutane with a nonclassical sigma sekeleton was obtained by reacting the dianion with a dichloroborane. A highly reactive derivative of the so far unknown triboracyclobutane was fully characterized by NMR spectroscopy at ?100°C. Its double aromatic electronic structure is definitely established by its 11B chemical shifts as compared to computed shifts for model compounds. Nonclassical triboracylobutane is thus shown to be the homo form of the double aromatic triboracyclopropane known only from computations.So far unknown two-electron aromatics with classical and nonclassical sigma skeletons are acquired experimentally in this dissertation (PhD thesis). By synthesis and X-ray structural analysis of the first dianion of a tetraboracyclobutane (tetaraborane(4)), the series of puckered four membered two-electron aromatics with classical sigma skeletons was completed. Prerequisite for this was the development (design) of perparative route to the precursor, which was accessible only in very low yields (0.5%) before. A new planar two-electron aromatic tetraboracyclobutane with a nonclassical sigma sekeleton was obtained by reacting the dianion with a dichloroborane. A highly reactive derivative of the so far unknown triboracyclobutane was fully characterized by NMR spectroscopy at ?100°C. Its double aromatic electronic structure is definitely established by its 11B chemical shifts as compared to computed shifts for model compounds. Nonclassical triboracylobutane is thus shown to be the homo form of the double aromatic triboracyclopropane known only from computations.

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Mesbah, Wahid (128657758): Kristallstruktur eines aromatischen Tetraboran(4)-Dianions, ein nichtklassisches Triboracyclobutan und ein Borylboratiren mit sehr starker C-B-Hyperkonjugation. : Philipps-Universität Marburg 2003-12-22. DOI: https://doi.org/10.17192/z2003.0710.

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This item has been published with the following license: In Copyright