title: A macrocyclic chelator with unprecedented Th⁴⁺ affinity.
abstract: A novel macrocyclic octadentate ligand incorporating terephthalamide binding units has been synthesized and evaluated for the chelation of Th(4+). The thorium complex was structurally characterized by X-ray diffraction and in solution with kinetic studies and spectrophotometric titrations. Dye displacement kinetic studies show that the ligand is a much more rapid chelator of Th(4+) than prevailing ligands (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid and diethylenetriaminepentaacetic acid). Furthermore, the resulting complex was found to have a remarkably high thermodynamic stability, with a formation constant of 10(54). These data support potential radiotherapeutic applications.
authors.affiliation: Department of Chemistry, University of California, Berkeley , Berkeley, California 94720-1460, United States.
authors.forename: Tiffany A
authors.initials: TA
authors.lastname: Pham
authors.forename: Jide
authors.initials: J
authors.lastname: Xu
authors.forename: Kenneth N
authors.initials: KN
authors.lastname: Raymond
mesh_terms: D002614:Chelating Agents / Q000138:chemical synthesis / Q000737:chemistry*; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D047028:Macrocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013816:Thermodynamics; D013910:Thorium / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D006573:Heterocyclic Compounds, 1-Ring; D008024:Ligands; D047028:Macrocyclic Compounds; D009942:Organometallic Compounds; C071349:1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid; D013910:Thorium