title: Functionalisation of lanthanide complexes via microwave-enhanced Cu(I)-catalysed azide-alkyne cycloaddition.
abstract: Cu(I)-catalysed azide-alkyne cycloaddition reactions were used to functionalise lanthanide(III)-complexes (Ln; La, Eu and Tb) incorporating alkyne or azide reactive groups. Microwave irradiation significantly accelerated the reactions, enabling full conversion to the triazole products in some cases in 5 min. Alkyl and aryl azides and alkyl and aryl alkynes could all serve as coupling partners. These reaction conditions proved efficient for cyclen-tricarboxylates and previously unreactive cyclen-tris-primary amide chelates. The synthesis of heterobimetallic (Eu/Tb, EuTb17 and Eu/La, EuLa17) and heterotrimetallic (Eu/La/Eu) complexes was achieved in up to 60% isolated yield starting from coumarin 2-appended alkynyl complexes Tb16 or La16 and an azido-Eu complex Eu4, and bis-alkynyl La-complex La5 and Eu4, respectively. EuTb17 displayed dual Eu(III) and Tb(III)-emission upon antenna-centred excitation.
authors.affiliation: Department of Chemistry-BMC, Uppsala University, SE-75123, Uppsala, Sweden.
authors.forename: Csongor
authors.initials: C
authors.lastname: Szíjjártó
authors.forename: Elias
authors.initials: E
authors.lastname: Pershagen
authors.forename: K Eszter
authors.initials: KE
authors.lastname: Borbas
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D001386:Azides / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D003500:Cyclization; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008872:Microwaves; D015394:Molecular Structure
chemical_list: D000480:Alkynes; D001386:Azides; D028581:Lanthanoid Series Elements; D003300:Copper