title: Complexation of the triphosphate anion: tuning the structure of cyclen based macrotricycles with 1,3-dimethylbenzene and 2,6-dimethylpyridine linkers. A potentiometric and NMR study.
abstract: The host-guest interaction between orthophosphate, pyrophosphate and triphosphate anions and three cyclen-based macrotricyclic ligands was investigated by potentiometric measurements and NMR spectroscopy. The ligands differ from one another by the nature of their spacers, which are 1,3-dimethylbenzene (TMC), 2,6-dimethylpyridine (TPyC) or a combination of the two (TMPyC). In aqueous solution, each ligand gave protonated species that further formed ternary complexes after binding with anions; these complexes were analyzed as a result of hydrogen bond formation and coulombic attraction between the organic host and the inorganic guest. The equilibrium constants found for all the detected species are reported and the selectivity, illustrated with species distribution diagrams, is discussed. The results unambiguously showed that the ligand possessing a single supplementary anchoring site (the pyridinyl spacer) exhibited the greatest affinity for the phosphate species in a large p[H] range.
authors.affiliation: UMR CNRS 6521, Chimie Electrochimie Moléculaire et Analytique, Université de Bretagne Occidentale, C. S. 93837, 29238, Brest Cedex 3, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Develay
authors.forename: Raphaël
authors.initials: R
authors.lastname: Tripier
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bernier
authors.forename: Michel
authors.initials: M
authors.lastname: Le Baccon
authors.forename: Véronique
authors.initials: V
authors.lastname: Patinec
authors.forename: Guy
authors.initials: G
authors.lastname: Serratrice
authors.forename: Henri
authors.initials: H
authors.lastname: Handel
mesh_terms: D002614:Chelating Agents / Q000737:chemistry*; D000080027:Cyclams; D011756:Diphosphates / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D010710:Phosphates / Q000737:chemistry*; D011083:Polycyclic Compounds / Q000737:chemistry*; D011199:Potentiometry; D011522:Protons; D011725:Pyridines / Q000737:chemistry*; D014992:Xylenes / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D000080027:Cyclams; D011756:Diphosphates; D006571:Heterocyclic Compounds; D008024:Ligands; D010710:Phosphates; D011083:Polycyclic Compounds; D011522:Protons; D011725:Pyridines; D014992:Xylenes; C038072:cyclen