0000000000326074
AUTHOR
Jean-pierre Barbier
Equilibrium and structural studies of complexes with a hexadentate ligand containing amide, amine and pyridyl nitrogen donors. Crystal structures of copper(II), nickel(II) and cobalt(III) complexes
A novel potentially hexadentate ligand, 1,8-bis(2-pyridylcarbamoyl)-3,6-diazaoctane (pyctrien) has been synthesised as its tetrahydrochloride salt; its protonation constants and the stability constants of the copper(II) and nickel(II) chelates have been determined by potentiometry. Amide group deprotonation permits the formation of [MLH−1]+ and [MLH−2] species in all cases, whereas the detection of the neutral or the protonated species depends on the nature of the metal ions. The solid complexes of copper, nickel and cobalt with the neutral and the deprotonated ligand have been synthesised and characterised by IR and UV–VIS spectroscopy. The amidic groups are coordinated through the oxygen …
Copper(II) and nickel(II) complexes of pyridylamido hexadentate ligands: chemical speciation and spectroscopic studies
Abstract Two novel potentially hexadentate ligands, 1,10-(2-bis picolinamide)-4,7-diazadecane (pycdpnen) and 1,8-bis(2-picolinamide)-3,6-dioxaoctane (pycdado) have been synthesised as their hydrochloride salt; its protonation constants and the stability constants of the copper(II) and nickel(II) chelates have been determined by potentiometry. Amide groups deprotonation permits the formation of [MLH −1 ] + species in all cases, while only pycdado gives [MLH −2 ] species. The solid complexes of copper and nickel with the neutral and the deprotonated ligands have been synthesised and characterised by IR, UV–Vis and ESR spectroscopy. The amidic groups are coordinated through the oxygen atoms in…