title: Synthesis, characterization, and luminescence properties of a new series of Eu3+-containing macrocycles.
abstract: The synthesis and structural characterization of a series of neutral Eu(3+)-containing macrocyclic complexes, Eu(4)-Eu(7), are reported. The synthetic pathway herein allows for the size and functionality of the macrocycle to be tailored in one step from a common precursor (N,N' '-bis(p-isothiocyanatobenzylcarbamoylmethyl)diethylenetriamine-N,N'N' '-triacetic acid, (3) in high yield. The macrocyclic ligands 4-7 have within their structure a bis-amide derivative of diethylenetriaminepentaacetic acid (DTPA) functioning as the europium chelate that is bridged through thiourea groups by either a butyl (4), hexyl (5), octyl (6), or m-benzyl (7) linker. The two thiourea groups were designed into the host macrocycle to serve as hydrogen-bond donors to potential guest molecules that may alter the luminescence properties of the parent macrocycle. Characterization of the luminescence of Eu(4)-Eu(7) reveals an antenna effect from the ligand, and the luminescence lifetime data reveals the presence of one coordinated water molecule in aqueous solution.
authors.affiliation: Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, USA.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Gulgas
authors.forename: Theresa M
authors.initials: TM
authors.lastname: Reineke
mesh_terms: D003500:Cyclization; D005063:Europium / Q000737:chemistry*; D049449:Luminescence; D015394:Molecular Structure; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D005063:Europium