title: Monopicolinate-dipicolyl derivative of triazacyclononane for stable complexation of Cu2+ and 64Cu2+.
abstract: The synthesis and characterization of Hno1pa2py, a new tacn-based ligand, is reported. The complexation process with Cu(2+) was proved to be very fast even in acidic medium. Potentiometric titrations allowed us to establish that Hno1pa2py exhibits an overall low basicity as well as a high selectivity for Cu(2+) over Zn(2+) cations. The copper(II) complex was synthesized and characterized using UV-vis and EPR spectroscopies and density functional theory (DFT) calculations. The studies clearly showed that the [Cu(no1pa2py)](+) complex is present in solution as a mixture of two isomers in which the ligand is coordinated to the metal center using a N5O donor set with the metal center in a distorted octahedral geometry. The very high kinetic inertness of the [Cu(no1pa2py)](+) complex was demonstrated by using acid-assisted dissociation assays as well as cyclic voltammetry. Preliminary investigations of (64)Cu complexation were performed to validate the potential use of such chelating agent for further application in nuclear medicine. The X-ray crystal structures of copper(II) complexes of L1, the ester derivative of Hno1pa2py, have been determined.
authors.affiliation: Université de Bretagne Occidentale, UMR-CNRS 6521, UFR des Sciences et Techniques, 6 avenue Victor le Gorgeu, C.S. 93837, 29238 Brest Cedex 3, France.
authors.forename: Melissa
authors.initials: M
authors.lastname: Roger
authors.forename: Luís M P
authors.initials: LM
authors.lastname: Lima
authors.forename: Mathieu
authors.initials: M
authors.lastname: Frindel
authors.forename: Carlos
authors.initials: C
authors.lastname: Platas-Iglesias
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Gestin
authors.forename: Rita
authors.initials: R
authors.lastname: Delgado
authors.forename: Véronique
authors.initials: V
authors.lastname: Patinec
authors.forename: Raphaël
authors.initials: R
authors.lastname: Tripier
mesh_terms: D001372:Aza Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D008024:Ligands; D008958:Models, Molecular; D010848:Picolinic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D010880:Piperidines / Q000138:chemical synthesis / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001372:Aza Compounds; D056831:Coordination Complexes; D008024:Ligands; D010848:Picolinic Acids; D010880:Piperidines; C482777:triazacyclononane; D003300:Copper; C030614:picolinic acid