title: [15]aneN4S: synthesis, thermodynamic studies and potential applications in chelation therapy.
abstract: The purpose of this work was to synthesize and characterize the thiatetraaza macrocycle 1-thia-4,7,10,13-tetraazacyclopentadecane ([15]aneN4S). Its acid-base behaviour was studied by potentiometry at 25 °C and ionic strength 0.10 M in KNO3. The protonation sequence of this ligand was investigated by 1H-NMR titration that also allowed the determination of protonation constants in D2O. Binding studies of [15]aneN4S with Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+ and Pb2+ metal ions were further performed under the same experimental conditions. The results demonstrated that this compound has a higher selectivity and thermodynamic stability for Hg2+ and Cu2+, followed by Ni2+. The UV-visible-near IR spectroscopies and magnetic moment data for the Co(II) and Ni(II) complexes indicated a tetragonal distorted coordination geometry for both metal centres. The value of magnetic moment and the X-band EPR spectra of the Cu(II) complex are consistent with a distorted square pyramidal geometry.
authors.affiliation: Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa 1649-003, Portugal. nunotorr@gmail.com.
authors.forename: Nuno
authors.initials: N
authors.lastname: Torres
authors.affiliation: Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa 1649-003, Portugal. sandrinagoncalves@campus.ul.pt.
authors.forename: Sandrina
authors.initials: S
authors.lastname: Gonçalves
authors.affiliation: Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa 1649-003, Portugal. ana.fernandes@ulusofona.pt.
authors.forename: Ana S
authors.initials: AS
authors.lastname: Fernandes
authors.affiliation: Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa 1649-003, Portugal. joaomachado@campus.ul.pt.
authors.forename: J Franco
authors.initials: JF
authors.lastname: Machado
authors.affiliation: Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa 1649-003, Portugal. mjbrito@fc.ul.pt.
authors.forename: Maria J Villa
authors.initials: MJ
authors.lastname: de Brito
authors.affiliation: Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa 1649-003, Portugal. ngoliveira@ff.ul.pt.
authors.forename: Nuno G
authors.initials: NG
authors.lastname: Oliveira
authors.affiliation: Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa 1649-003, Portugal. mcastro@ff.ul.pt.
authors.forename: Matilde
authors.initials: M
authors.lastname: Castro
authors.affiliation: Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa 1649-003, Portugal. fcabral@ff.ul.pt.
authors.forename: Judite
authors.initials: J
authors.lastname: Costa
authors.affiliation: Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa 1649-003, Portugal. mcastro@ff.ul.pt.
authors.forename: Maria F
authors.initials: MF
authors.lastname: Cabral
mesh_terms: D001372:Aza Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D002614:Chelating Agents / Q000737:chemistry / Q000494:pharmacology; D004355:Drug Stability; D047028:Macrocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D008670:Metals / Q000737:chemistry; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013816:Thermodynamics
chemical_list: D001372:Aza Compounds; D002614:Chelating Agents; D047028:Macrocyclic Compounds; D008670:Metals