{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:60099"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:60099","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Aluminiumorganisch stabilisierte Übergangsmetallkolloide : Synthese, Bildungsmechanismus und Aufbau von organisierten Strukturen","abstract":"Subject of the dissertation is the synthesis and characterization of novel, nanoscopic transition metal colloids having reactive aluminumorganic protecting shells, and the formation of 3-D nanoparticle networks. The synthesis of aluminumorganic stabilized platinum colloids was investigated using the reaction of Pt(II)-acetylacetonate with aluminumtrimethyl. A novel di-platinum complex was identified as the key intermediate of the colloid formation. This complex decomposes in solution under formation of nanoscopic platinum particles with a mean diameter of 1.2 nm. The formation of these particles in solution was studied with Anomalous Small Angle X-ray Scattering (ASAXS). The isolated platinum colloids were characterized further with several analytic methods like Electron Microscopy (TEM) and X-ray Absorption Spectroscopy (XANES, EXAFS). The investigations showed, that the particles consist of zero-valent platinum with an aluminumorganic protecting shell containing reactive aluminum-methyl-groups. These reactive aluminum-methyl-groups are the prerequisite for the interconnection of the particles to form a 3-D nanoparticle network. For that purpose, the colloids are reacted with proton-active bifunctional \"spacer-molecules\". Suitable spacer molecules are diols or dicarboxylic acids which react with the aluminum-alkyl groups in the protecting shell under cleavage of methane. The structure and the electronic- and catalytic properties of the resulting Pt-nanoparticle-networks were intensively characterized. The investigations revealed, that the structure of the networks is strongly depending on the \"spacer-molecule\" chosen. The mean interparticle distance in the network increases with increasing length of the \"spacer molecule\". Variation of the \"spacer molecule\" also allows the pore-sizes and the specific surface areas to be tailored. Furthermore catalytic tests showed, that the Pt-nanoparticle networks are very efficient heterogeneous catalysts for the hydrogenation of alkenes.","abstract_html":"Subject of the dissertation is the synthesis and characterization of novel, nanoscopic transition metal colloids having reactive aluminumorganic protecting shells, and the formation of 3-D nanoparticle networks. The synthesis of aluminumorganic stabilized platinum colloids was investigated using the reaction of Pt(II)-acetylacetonate with aluminumtrimethyl. A novel di-platinum complex was identified as the key intermediate of the colloid formation. This complex decomposes in solution under formation of nanoscopic platinum particles with a mean diameter of 1.2 nm. The formation of these particles in solution was studied with Anomalous Small Angle X-ray Scattering (ASAXS). The isolated platinum colloids were characterized further with several analytic methods like Electron Microscopy (TEM) and X-ray Absorption Spectroscopy (XANES, EXAFS). The investigations showed, that the particles consist of zero-valent platinum with an aluminumorganic protecting shell containing reactive aluminum-methyl-groups. These reactive aluminum-methyl-groups are the prerequisite for the interconnection of the particles to form a 3-D nanoparticle network. For that purpose, the colloids are reacted with proton-active bifunctional "spacer-molecules". Suitable spacer molecules are diols or dicarboxylic acids which react with the aluminum-alkyl groups in the protecting shell under cleavage of methane. The structure and the electronic- and catalytic properties of the resulting Pt-nanoparticle-networks were intensively characterized. The investigations revealed, that the structure of the networks is strongly depending on the "spacer-molecule" chosen. The mean interparticle distance in the network increases with increasing length of the "spacer molecule". Variation of the "spacer molecule" also allows the pore-sizes and the specific surface areas to be tailored. Furthermore catalytic tests showed, that the Pt-nanoparticle networks are very efficient heterogeneous catalysts for the hydrogenation of alkenes.","abstract_has_math":false,"creators":["Waldöfner, Norbert"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Bönnemann, Helmut"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002","date_published":"2002","updated_at":"2026-07-30T19:42:48Z","subjects":["info:eu-repo/classification/ddc/540","Chemie"],"languages":["ger"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121826%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121826%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121826%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/60099","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Bönnemann, Helmut"]},{"key":"dc:creator","label":"Author","values":["Waldöfner, Norbert"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2002"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-3664"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/540","Chemie"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["ger"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/60099","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121826%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Subject of the dissertation is the synthesis and characterization of novel, nanoscopic transition metal colloids having reactive aluminumorganic protecting shells, and the formation of 3-D nanoparticle networks. The synthesis of aluminumorganic stabilized platinum colloids was investigated using the reaction of Pt(II)-acetylacetonate with aluminumtrimethyl. A novel di-platinum complex was identified as the key intermediate of the colloid formation. This complex decomposes in solution under formation of nanoscopic platinum particles with a mean diameter of 1.2 nm. The formation of these particles in solution was studied with Anomalous Small Angle X-ray Scattering (ASAXS). The isolated platinum colloids were characterized further with several analytic methods like Electron Microscopy (TEM) and X-ray Absorption Spectroscopy (XANES, EXAFS). The investigations showed, that the particles consist of zero-valent platinum with an aluminumorganic protecting shell containing reactive aluminum-methyl-groups. These reactive aluminum-methyl-groups are the prerequisite for the interconnection of the particles to form a 3-D nanoparticle network. For that purpose, the colloids are reacted with proton-active bifunctional \"spacer-molecules\". Suitable spacer molecules are diols or dicarboxylic acids which react with the aluminum-alkyl groups in the protecting shell under cleavage of methane. The structure and the electronic- and catalytic properties of the resulting Pt-nanoparticle-networks were intensively characterized. The investigations revealed, that the structure of the networks is strongly depending on the \"spacer-molecule\" chosen. The mean interparticle distance in the network increases with increasing length of the \"spacer molecule\". Variation of the \"spacer molecule\" also allows the pore-sizes and the specific surface areas to be tailored. Furthermore catalytic tests showed, that the Pt-nanoparticle networks are very efficient heterogeneous catalysts for the hydrogenation of alkenes."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University 172 Bl. : graph. Darst. (2002). = Aachen, Techn. Hochsch., Diss., 2002"]},{"key":"dc:title","label":"Title","values":["Aluminiumorganisch stabilisierte Übergangsmetallkolloide : Synthese, Bildungsmechanismus und Aufbau von organisierten Strukturen"]}]}],"canonical_facts":{"dc:contributor":["Bönnemann, Helmut"],"dc:coverage":["DE"],"dc:creator":["Waldöfner, Norbert"],"dc:date":["2002"],"dc:description":["Subject of the dissertation is the synthesis and characterization of novel, nanoscopic transition metal colloids having reactive aluminumorganic protecting shells, and the formation of 3-D nanoparticle networks. The synthesis of aluminumorganic stabilized platinum colloids was investigated using the reaction of Pt(II)-acetylacetonate with aluminumtrimethyl. A novel di-platinum complex was identified as the key intermediate of the colloid formation. This complex decomposes in solution under formation of nanoscopic platinum particles with a mean diameter of 1.2 nm. The formation of these particles in solution was studied with Anomalous Small Angle X-ray Scattering (ASAXS). The isolated platinum colloids were characterized further with several analytic methods like Electron Microscopy (TEM) and X-ray Absorption Spectroscopy (XANES, EXAFS). The investigations showed, that the particles consist of zero-valent platinum with an aluminumorganic protecting shell containing reactive aluminum-methyl-groups. These reactive aluminum-methyl-groups are the prerequisite for the interconnection of the particles to form a 3-D nanoparticle network. For that purpose, the colloids are reacted with proton-active bifunctional \"spacer-molecules\". Suitable spacer molecules are diols or dicarboxylic acids which react with the aluminum-alkyl groups in the protecting shell under cleavage of methane. The structure and the electronic- and catalytic properties of the resulting Pt-nanoparticle-networks were intensively characterized. The investigations revealed, that the structure of the networks is strongly depending on the \"spacer-molecule\" chosen. The mean interparticle distance in the network increases with increasing length of the \"spacer molecule\". Variation of the \"spacer molecule\" also allows the pore-sizes and the specific surface areas to be tailored. Furthermore catalytic tests showed, that the Pt-nanoparticle networks are very efficient heterogeneous catalysts for the hydrogenation of alkenes."],"dc:identifier":["https://publications.rwth-aachen.de/record/60099","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121826%22"],"dc:language":["ger"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-3664"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University 172 Bl. : graph. Darst. (2002). = Aachen, Techn. Hochsch., Diss., 2002"],"dc:subject":["info:eu-repo/classification/ddc/540","Chemie"],"dc:title":["Aluminiumorganisch stabilisierte Übergangsmetallkolloide : Synthese, Bildungsmechanismus und Aufbau von organisierten Strukturen"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:42:48Z"}