{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:57167"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:57167","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Syntheses and structures of metal cyanamide compounds","abstract":"This thesis describes syntheses and structures of some metal cyanamide compounds, based on \"soft cations\" of metal elements. In PbNCN, the cyanamide anion exhibits two different C-N bond lengths. Quantum-chemical DFT calculations prove that the cyanamide anion is comparatively easy to distort. Two modification of mercury cyanamide has been synthesized by controlling the pH value. The X-ray analysis shows that Hg atoms and the one end of NCN units form zigzag chains in HgNCN(II), and two C-N bond lengths are significantly different. In HgNCN(I) NCN unit bonds to Hg atoms from the both sides and the two C-N bond lenghs are almost identical. The crystal structures of Hg2(NCN)Cl2 and Hg3(NCN)2Cl2 show that there are sharing edged 20-membered rings formed by [Hg3(NCN)2]2+ as a backbone, but the cavities of the rings are very flexible. Ag2NCN, as an example of a transition metal cyanamide, shows that NCN unit has mixed character of \"N=C=N\" and \"N?C-N\". The structure of Ag(H4N4C2)3NO3 shows that two dicyandiamides behave as a mono-dentate ligand through nitrile nitrogen atoms and the third dicyandiamide locates just in the vacant site binding by hydrogen bonds. In Ni(NCNH2)4Cl2, Co(NCNH2)4Cl2 and Cu(NCNH2)4Cl2, Ni2+, Co2+ or Cu2+ are octahedrally coordinated by four equatorial H2NCN molecules and two axial chloride ions. Ni(NCNH2)4Cl2/ Co(NCNH2)4Cl2 are Curie paramagnets with two/three unpaired electrons.","abstract_html":"This thesis describes syntheses and structures of some metal cyanamide compounds, based on "soft cations" of metal elements. In PbNCN, the cyanamide anion exhibits two different C-N bond lengths. Quantum-chemical DFT calculations prove that the cyanamide anion is comparatively easy to distort. Two modification of mercury cyanamide has been synthesized by controlling the pH value. The X-ray analysis shows that Hg atoms and the one end of NCN units form zigzag chains in HgNCN(II), and two C-N bond lengths are significantly different. In HgNCN(I) NCN unit bonds to Hg atoms from the both sides and the two C-N bond lenghs are almost identical. The crystal structures of Hg2(NCN)Cl2 and Hg3(NCN)2Cl2 show that there are sharing edged 20-membered rings formed by [Hg3(NCN)2]2+ as a backbone, but the cavities of the rings are very flexible. Ag2NCN, as an example of a transition metal cyanamide, shows that NCN unit has mixed character of "N=C=N" and "N?C-N". The structure of Ag(H4N4C2)3NO3 shows that two dicyandiamides behave as a mono-dentate ligand through nitrile nitrogen atoms and the third dicyandiamide locates just in the vacant site binding by hydrogen bonds. In Ni(NCNH2)4Cl2, Co(NCNH2)4Cl2 and Cu(NCNH2)4Cl2, Ni2+, Co2+ or Cu2+ are octahedrally coordinated by four equatorial H2NCN molecules and two axial chloride ions. Ni(NCNH2)4Cl2/ Co(NCNH2)4Cl2 are Curie paramagnets with two/three unpaired electrons.","abstract_has_math":false,"creators":["Liu, Xiaohui"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Dronskowski, Richard"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002","date_published":"2002","updated_at":"2026-07-30T19:42:09Z","subjects":["info:eu-repo/classification/ddc/540","Chemie","Metal Cyanamide"],"languages":["eng"],"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-119232%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-119232%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-119232%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/57167","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Dronskowski, Richard"]},{"key":"dc:creator","label":"Author","values":["Liu, Xiaohui"]}]},{"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-4670"]},{"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","Metal Cyanamide"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"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/57167","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-119232%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This thesis describes syntheses and structures of some metal cyanamide compounds, based on \"soft cations\" of metal elements. In PbNCN, the cyanamide anion exhibits two different C-N bond lengths. Quantum-chemical DFT calculations prove that the cyanamide anion is comparatively easy to distort. Two modification of mercury cyanamide has been synthesized by controlling the pH value. The X-ray analysis shows that Hg atoms and the one end of NCN units form zigzag chains in HgNCN(II), and two C-N bond lengths are significantly different. In HgNCN(I) NCN unit bonds to Hg atoms from the both sides and the two C-N bond lenghs are almost identical. The crystal structures of Hg2(NCN)Cl2 and Hg3(NCN)2Cl2 show that there are sharing edged 20-membered rings formed by [Hg3(NCN)2]2+ as a backbone, but the cavities of the rings are very flexible. Ag2NCN, as an example of a transition metal cyanamide, shows that NCN unit has mixed character of \"N=C=N\" and \"N?C-N\". The structure of Ag(H4N4C2)3NO3 shows that two dicyandiamides behave as a mono-dentate ligand through nitrile nitrogen atoms and the third dicyandiamide locates just in the vacant site binding by hydrogen bonds. In Ni(NCNH2)4Cl2, Co(NCNH2)4Cl2 and Cu(NCNH2)4Cl2, Ni2+, Co2+ or Cu2+ are octahedrally coordinated by four equatorial H2NCN molecules and two axial chloride ions. Ni(NCNH2)4Cl2/ Co(NCNH2)4Cl2 are Curie paramagnets with two/three unpaired electrons."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University II, 85 S. : graph. Darst. (2002). = Aachen, Techn. Hochsch., Diss., 2002"]},{"key":"dc:title","label":"Title","values":["Syntheses and structures of metal cyanamide compounds"]}]}],"canonical_facts":{"dc:contributor":["Dronskowski, Richard"],"dc:coverage":["DE"],"dc:creator":["Liu, Xiaohui"],"dc:date":["2002"],"dc:description":["This thesis describes syntheses and structures of some metal cyanamide compounds, based on \"soft cations\" of metal elements. In PbNCN, the cyanamide anion exhibits two different C-N bond lengths. Quantum-chemical DFT calculations prove that the cyanamide anion is comparatively easy to distort. Two modification of mercury cyanamide has been synthesized by controlling the pH value. The X-ray analysis shows that Hg atoms and the one end of NCN units form zigzag chains in HgNCN(II), and two C-N bond lengths are significantly different. In HgNCN(I) NCN unit bonds to Hg atoms from the both sides and the two C-N bond lenghs are almost identical. The crystal structures of Hg2(NCN)Cl2 and Hg3(NCN)2Cl2 show that there are sharing edged 20-membered rings formed by [Hg3(NCN)2]2+ as a backbone, but the cavities of the rings are very flexible. Ag2NCN, as an example of a transition metal cyanamide, shows that NCN unit has mixed character of \"N=C=N\" and \"N?C-N\". The structure of Ag(H4N4C2)3NO3 shows that two dicyandiamides behave as a mono-dentate ligand through nitrile nitrogen atoms and the third dicyandiamide locates just in the vacant site binding by hydrogen bonds. In Ni(NCNH2)4Cl2, Co(NCNH2)4Cl2 and Cu(NCNH2)4Cl2, Ni2+, Co2+ or Cu2+ are octahedrally coordinated by four equatorial H2NCN molecules and two axial chloride ions. Ni(NCNH2)4Cl2/ Co(NCNH2)4Cl2 are Curie paramagnets with two/three unpaired electrons."],"dc:identifier":["https://publications.rwth-aachen.de/record/57167","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-119232%22"],"dc:language":["eng"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-4670"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University II, 85 S. : graph. Darst. (2002). = Aachen, Techn. Hochsch., Diss., 2002"],"dc:subject":["info:eu-repo/classification/ddc/540","Chemie","Metal Cyanamide"],"dc:title":["Syntheses and structures of metal cyanamide compounds"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:42:09Z"}