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.
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.
Develay
Stéphanie
S
UMR CNRS 6521, Chimie Electrochimie Moléculaire et Analytique, Université de Bretagne Occidentale, C. S. 93837, 29238, Brest Cedex 3, France.
Tripier
Raphaël
R
Bernier
Nicolas
N
Le Baccon
Michel
M
Patinec
Véronique
V
Serratrice
Guy
G
Handel
Henri
H
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*
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