{"id":{"repo_id":"colostate","oai_identifier":"oai:mountainscholar.org:10217/244238"},"canonical_url":"https://search.dev.ndltd.org/etd/colostate/oai:mountainscholar.org:10217/244238","repository":{"repo_id":"colostate","name":"Colorado State University","base_url":"https://api.mountainscholar.org/server/oai/request"},"display":{"title":"Synthesis of alkyl- and poly(ethylene)glycol linked bis-dioxocyclams from bis-chromium carbene complexes","abstract":"Alkyl-linked bis-chromium carbene complexes have been prepared via deprotonation and α-alkylation of (methoxy)(methyl) chromium carbene complexes using l,n-bis-triflates as electrophiles. These bis-carbene complexes were then photolyzed with N-protected imidazolines to give protected bis-azapenams. Azapenams are known to undergo a dimerization reaction to form 14-membered bis-imine bis-dioxocyclams. Unfortunately, all attempts to reduce the imine-cyclams to give the stable dioxocyclams were unsuccessful. Both tri- and tetra(ethylene glycol) linked bis-chromium carbene complexes have been synthesized. These carbene complexes were photolyzed with imidazolines to give protected azapenams. The azapenams were transformed into polyether-linked basket dioxocyclams and bis-dioxocyclams. These compounds have cavities for the complexation of both \"hard\" and \"soft\" metal ions. The complexes of nickel, barium, and gadolinium were synthesized.","abstract_html":"Alkyl-linked bis-chromium carbene complexes have been prepared via deprotonation and α-alkylation of (methoxy)(methyl) chromium carbene complexes using l,n-bis-triflates as electrophiles. These bis-carbene complexes were then photolyzed with N-protected imidazolines to give protected bis-azapenams. Azapenams are known to undergo a dimerization reaction to form 14-membered bis-imine bis-dioxocyclams. Unfortunately, all attempts to reduce the imine-cyclams to give the stable dioxocyclams were unsuccessful. Both tri- and tetra(ethylene glycol) linked bis-chromium carbene complexes have been synthesized. These carbene complexes were photolyzed with imidazolines to give protected azapenams. The azapenams were transformed into polyether-linked basket dioxocyclams and bis-dioxocyclams. These compounds have cavities for the complexation of both "hard" and "soft" metal ions. The complexes of nickel, barium, and gadolinium were synthesized.","abstract_has_math":false,"creators":["Kuester, Erik M., author","Hegedus, L. S., advisor"],"institution":"Colorado State University. 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Both tri- and tetra(ethylene glycol) linked bis-chromium carbene complexes have been synthesized. These carbene complexes were photolyzed with imidazolines to give protected azapenams. The azapenams were transformed into polyether-linked basket dioxocyclams and bis-dioxocyclams. These compounds have cavities for the complexation of both \"hard\" and \"soft\" metal ions. The complexes of nickel, barium, and gadolinium were synthesized."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["doctoral dissertations"]},{"key":"dc:title","label":"Title","values":["Synthesis of alkyl- and poly(ethylene)glycol linked bis-dioxocyclams from bis-chromium carbene complexes"]}]}],"canonical_facts":{"dc:creator":["Kuester, Erik M., author","Hegedus, L. S., advisor"],"dc:date.accessioned":["2026-04-22T18:24:21Z"],"dc:date.issued":["2000"],"dc:description.abstract":["Alkyl-linked bis-chromium carbene complexes have been prepared via deprotonation and α-alkylation of (methoxy)(methyl) chromium carbene complexes using l,n-bis-triflates as electrophiles. These bis-carbene complexes were then photolyzed with N-protected imidazolines to give protected bis-azapenams. Azapenams are known to undergo a dimerization reaction to form 14-membered bis-imine bis-dioxocyclams. Unfortunately, all attempts to reduce the imine-cyclams to give the stable dioxocyclams were unsuccessful. Both tri- and tetra(ethylene glycol) linked bis-chromium carbene complexes have been synthesized. These carbene complexes were photolyzed with imidazolines to give protected azapenams. The azapenams were transformed into polyether-linked basket dioxocyclams and bis-dioxocyclams. These compounds have cavities for the complexation of both \"hard\" and \"soft\" metal ions. 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