{"id":{"repo_id":"penn","oai_identifier":"oai:repository.upenn.edu:20.500.14332/29546"},"canonical_url":"https://search.dev.ndltd.org/etd/penn/oai:repository.upenn.edu:20.500.14332/29546","repository":{"repo_id":"penn","name":"University of Pennsylvania","base_url":"https://repository.upenn.edu/server/oai/request"},"display":{"title":"6- and 5-Halodecaboranes: Selective Syntheses From ClOSO-B10H10(2-) and Use as Polyborane Building Blocks","abstract":"Decaborane halogenated in the 6-position has been synthesized in high yields via the super-acid induced cage-opening reactions of closo-B10H10(2-) salts. These 6-halogenated compounds were then isomerized to their 5-substituted isomers through base catalysis. The isomerization was driven by the energy differences between the anionic-forms of each respective isomer. These reactions provided 5-halodeboranes in high yields. The bridging-hydrogens of the halodecaboranyl anions were fluxional at a range of temperatures. Variable-temperature NMR studies supported computationally proposed fluxional mechanisms. Both 5- and 6-halodecaboranes were reacted with alcohols yielding boranyl ethers. The mechanisms of substitution, where reactions with 6- and 5-halodecaboranes yielded 5- and 6-boranyl ethers, respectively, were explained computationally and confirmed through isotopic-labeling studies. The regeneration of the polymeric products of ammonia-borane dehydrogenation was carried out through a process that included digestion of the polymer, complexation of the digestate with a base, reduction of B-X bonds to B-H bonds, and finally displacement of the base with ammonia. While digestion schemes proved unable to digest all forms of the dehydrogenated materials, portions of the polymer digested to boron-trihalides were quantitatively regenerated to ammonia borane, with complete separation and collection of by-products.","abstract_html":"Decaborane halogenated in the 6-position has been synthesized in high yields via the super-acid induced cage-opening reactions of closo-B10H10(2-) salts. These 6-halogenated compounds were then isomerized to their 5-substituted isomers through base catalysis. The isomerization was driven by the energy differences between the anionic-forms of each respective isomer. These reactions provided 5-halodeboranes in high yields. The bridging-hydrogens of the halodecaboranyl anions were fluxional at a range of temperatures. Variable-temperature NMR studies supported computationally proposed fluxional mechanisms. Both 5- and 6-halodecaboranes were reacted with alcohols yielding boranyl ethers. The mechanisms of substitution, where reactions with 6- and 5-halodecaboranes yielded 5- and 6-boranyl ethers, respectively, were explained computationally and confirmed through isotopic-labeling studies. The regeneration of the polymeric products of ammonia-borane dehydrogenation was carried out through a process that included digestion of the polymer, complexation of the digestate with a base, reduction of B-X bonds to B-H bonds, and finally displacement of the base with ammonia. While digestion schemes proved unable to digest all forms of the dehydrogenated materials, portions of the polymer digested to boron-trihalides were quantitatively regenerated to ammonia borane, with complete separation and collection of by-products.","abstract_has_math":false,"creators":["Ewing, William C"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Larry G. Sneddon"],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010-12-22","date_published":"2010-12-22","updated_at":"2026-07-24T03:46:44Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://repository.upenn.edu/handle/20.500.14332/29546","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Larry G. Sneddon"]},{"key":"dc:creator","label":"Author","values":["Ewing, William C"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2023-05-17T05:56:44.000"]},{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2023-05-22T17:11:32Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2010-12-06T00:00:00Z"]},{"key":"dc:date.issued","label":"Date","values":["2010-12-22"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation/Thesis"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://repository.upenn.edu/handle/20.500.14332/29546"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Decaborane halogenated in the 6-position has been synthesized in high yields via the super-acid induced cage-opening reactions of closo-B10H10(2-) salts. These 6-halogenated compounds were then isomerized to their 5-substituted isomers through base catalysis. The isomerization was driven by the energy differences between the anionic-forms of each respective isomer. These reactions provided 5-halodeboranes in high yields. The bridging-hydrogens of the halodecaboranyl anions were fluxional at a range of temperatures. Variable-temperature NMR studies supported computationally proposed fluxional mechanisms. Both 5- and 6-halodecaboranes were reacted with alcohols yielding boranyl ethers. The mechanisms of substitution, where reactions with 6- and 5-halodecaboranes yielded 5- and 6-boranyl ethers, respectively, were explained computationally and confirmed through isotopic-labeling studies. The regeneration of the polymeric products of ammonia-borane dehydrogenation was carried out through a process that included digestion of the polymer, complexation of the digestate with a base, reduction of B-X bonds to B-H bonds, and finally displacement of the base with ammonia. While digestion schemes proved unable to digest all forms of the dehydrogenated materials, portions of the polymer digested to boron-trihalides were quantitatively regenerated to ammonia borane, with complete separation and collection of by-products."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Doctor of Philosophy (PhD)"]},{"key":"dc:title","label":"Title","values":["6- and 5-Halodecaboranes: Selective Syntheses From ClOSO-B10H10(2-) and Use as Polyborane Building Blocks"]}]}],"canonical_facts":{"dc:contributor.advisor":["Larry G. Sneddon"],"dc:creator":["Ewing, William C"],"dc:date":["2023-05-17T05:56:44.000"],"dc:date.accessioned":["2023-05-22T17:11:32Z"],"dc:date.available":["2010-12-06T00:00:00Z"],"dc:date.issued":["2010-12-22"],"dc:description.abstract":["Decaborane halogenated in the 6-position has been synthesized in high yields via the super-acid induced cage-opening reactions of closo-B10H10(2-) salts. These 6-halogenated compounds were then isomerized to their 5-substituted isomers through base catalysis. The isomerization was driven by the energy differences between the anionic-forms of each respective isomer. These reactions provided 5-halodeboranes in high yields. The bridging-hydrogens of the halodecaboranyl anions were fluxional at a range of temperatures. Variable-temperature NMR studies supported computationally proposed fluxional mechanisms. Both 5- and 6-halodecaboranes were reacted with alcohols yielding boranyl ethers. The mechanisms of substitution, where reactions with 6- and 5-halodecaboranes yielded 5- and 6-boranyl ethers, respectively, were explained computationally and confirmed through isotopic-labeling studies. The regeneration of the polymeric products of ammonia-borane dehydrogenation was carried out through a process that included digestion of the polymer, complexation of the digestate with a base, reduction of B-X bonds to B-H bonds, and finally displacement of the base with ammonia. While digestion schemes proved unable to digest all forms of the dehydrogenated materials, portions of the polymer digested to boron-trihalides were quantitatively regenerated to ammonia borane, with complete separation and collection of by-products."],"dc:description.degree":["Doctor of Philosophy (PhD)"],"dc:identifier.uri":["https://repository.upenn.edu/handle/20.500.14332/29546"],"dc:title":["6- and 5-Halodecaboranes: Selective Syntheses From ClOSO-B10H10(2-) and Use as Polyborane Building Blocks"],"dc:type":["Dissertation/Thesis"]},"updated_at":"2026-07-24T03:46:44Z"}