title: Potentiometric and spectrophotometric equilibrium study on Fe(III) and new catechol-bisphosphonate conjugates.
abstract: The coordination properties of mixed catechol-bisphosphonates towards Fe(III) are presented. From the potentiometric and spectroscopic results it was possible to state that iron coordination takes place only on the bisphosphonate moiety at acidic pH, and involves both catechol and bisphosphonate groups on two different iron(III) ions at higher pH values. Steric constracts keep both groups from chelating the same metal ion. Quantum mechanical calculations confirm this statement and allow to determine the minimum length of the linker for a stable conformation of complexes in which the same iron(III) ion is coordinated by both catechol and bisphosphonate.
authors.affiliation: Centro Interdipartimentale per lo Studio dei Metalli in Medicina, Dipartimento di Scienze Chimiche, Cittadella Universitaria, 09042 Monserrato-Cagliari, Italy. crisponi@unica.it
authors.forename: Guido
authors.initials: G
authors.lastname: Crisponi
authors.forename: Valeria Marina
authors.initials: VM
authors.lastname: Nurchi
authors.forename: Tiziana
authors.initials: T
authors.lastname: Pivetta
mesh_terms: D002396:Catechols / Q000737:chemistry*; D004164:Diphosphonates / Q000737:chemistry*; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D008024:Ligands; D015394:Molecular Structure; D011199:Potentiometry; D013053:Spectrophotometry
chemical_list: D002396:Catechols; D004164:Diphosphonates; D005290:Ferric Compounds; D008024:Ligands; D007501:Iron; C034221:catechol