title: Coordination features of ditopic oxa-azamacrocycles toward Ni(II) and Co(II). Dioxygen uptake by their dinuclear Co(II) complexes.
abstract: The coordination properties of the ditopic oxa-aza macrocycles L1-L3 toward Ni(II) and Co(II) have been investigated by means of potentiometric and UV-vis spectrophotometric measurements. L1-L3 contain two triamine and/or tetraamine chains separated by two dioxa chains and form both mono- and dinuclear complexes in aqueous solution. In the [ML]2+ complexes, the metal ion is coordinated by one of the two polyamine moieties, while the other does not participate in the coordination. In the dinuclear complexes each metal ion is coordinated, almost independently, to a single polyamine moiety. Under aerobic conditions the binuclear Co(II) complexes of the ligands L1-L3 are able to bind molecular oxygen, with a bridging coordination of O2 between the two metals.
authors.affiliation: Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Bazzicalupi
authors.forename: Andrea
authors.initials: A
authors.lastname: Bencini
authors.forename: Antonio
authors.initials: A
authors.lastname: Bianchi
authors.forename: Celia
authors.initials: C
authors.lastname: Duce
authors.forename: Patrizia
authors.initials: P
authors.lastname: Fornasari
authors.forename: Claudia
authors.initials: C
authors.lastname: Giorgi
authors.forename: Piero
authors.initials: P
authors.lastname: Paoletti
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Pardini
authors.forename: Maria
authors.initials: M
authors.lastname: Rosaria Tinè
authors.forename: Barbara
authors.initials: B
authors.lastname: Valtancoli
mesh_terms: D001372:Aza Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006863:Hydrogen-Ion Concentration; D047028:Macrocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*
chemical_list: D001372:Aza Compounds; D047028:Macrocyclic Compounds; D009942:Organometallic Compounds; D003035:Cobalt; D009532:Nickel; D010100:Oxygen