6533b7ddfe1ef96bd1273e68

RESEARCH PRODUCT

Copper(II) and nickel(II) complexes of pyridylamido hexadentate ligands: chemical speciation and spectroscopic studies

Jean-pierre BarbierStéphane BrandèsChristian GérardAminou MohamadouAlain TabardCaroline Jubert

subject

chemistry.chemical_classification010405 organic chemistryHydrochlorideInorganic chemistrychemistry.chemical_elementSalt (chemistry)Protonation[CHIM.INOR]Chemical Sciences/Inorganic chemistry010402 general chemistry01 natural sciencesCopper0104 chemical sciencesInorganic ChemistryNickelchemistry.chemical_compoundDeprotonationchemistryAmidePolymer chemistryMaterials ChemistryChelation[CHIM.COOR]Chemical Sciences/Coordination chemistryPhysical and Theoretical ChemistryComputingMilieux_MISCELLANEOUS

description

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 all solid complexes [ML](ClO 4 ) 2 (M=Cu 2+ and Ni 2+ ). The complexes obtained with the deprotonated forms of the ligands imply the coordination through the nitrogen atoms of the amidic groups.

10.1016/s1387-7003(03)00139-4https://hal.univ-reims.fr/hal-01888223