title: Coordination and structural studies of crowned-porphyrins.
abstract: Simple chelating agents have been synthesized using a porphyrin and a covalently linked crown-ether. Depending on the relative spatial arrangement of both motifs, the resulting ligands, either a macrotricycle or bis-macrocycles, differ one from another by their flexibility or their aptitude to chelate bivalent or trivalent cations. The coordination chemistry as well as the structural study of these ligands and complexes are reported. In the particular case of the macrotricycle, the crown-ether motif, perpendicular to the porphyrin induces a side selectivity for the coordination of lead(II) outside the cavity. Furthermore, the coordination of zinc(II) implies a change of conformation of the ligand in which the crown-ether is parallel to the porphyrin.
authors: Sciences Chimiques de Rennes, UMR CNRS 6226, Ingénierie Chimique et Molécules pour le Vivant, 35042, Rennes Cedex, France.
authors: Zakaria
authors: Z
authors: Halime
authors: Mohammed
authors: M
authors: Lachkar
authors: Loïc
authors: L
authors: Toupet
authors: Athanassios G
authors: AG
authors: Coutsolelos
authors: Bernard
authors: B
authors: Boitrel
mesh_terms: D002614:Chelating Agents / Q000138:chemical synthesis* / Q000737:chemistry; D043844:Crown Ethers / Q000737:chemistry; D007854:Lead / Q000737:chemistry*; D015394:Molecular Structure; D011166:Porphyrins / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D043844:Crown Ethers; D011166:Porphyrins; D007854:Lead; D015032:Zinc