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
| Autor: | Stéphane Brandès, Jean-Pierre Barbier, Aminou Mohamadou, Christian Gérard, Caroline Jubert, Alain Tabard |
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| Přispěvatelé: | Institut de Chimie Moléculaire de Reims - UMR 7312 (ICMR), SFR Condorcet, Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-SFR CAP Santé (Champagne-Ardenne Picardie Santé), Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Université de Reims Champagne-Ardenne (URCA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mathématiques d'Orsay (LM-Orsay), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Institut de Chimie Moléculaire de l'Université de Bourgogne [Dijon] (ICMUB), Université de Bourgogne (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
| Předmět: |
inorganic chemicals
010405 organic chemistry Ligand Inorganic chemistry chemistry.chemical_element Protonation General Chemistry [CHIM.INOR]Chemical Sciences/Inorganic chemistry 010402 general chemistry 01 natural sciences Square pyramidal molecular geometry 0104 chemical sciences chemistry.chemical_compound Nickel Crystallography Deprotonation chemistry Amide Pyridine [CHIM.COOR]Chemical Sciences/Coordination chemistry Cobalt ComputingMilieux_MISCELLANEOUS |
| Zdroj: | Scopus-Elsevier Journal of the Chemical Society Dalton Transactions Journal of the Chemical Society Dalton Transactions, Royal Society of Chemistry, The, 2002, ⟨10.1039/B111614B⟩ |
| ISSN: | 1472-7773 1364-5447 |
| Popis: | 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 atoms in all solid complexes [ML](ClO4)2 (M = Cu2+, Ni2+ and Co2+). The complexes obtained with the deprotonated forms of the ligand imply the coordination through the nitrogen atoms of the amidic groups. In the cobalt compound, the coordination of the six nitrogen donor atoms leads to the spontaneous oxidation of Co(II) into Co(III); thus, NMR spectroscopic investigations show that this complex has an α-cis configuration. X-Ray crystal determination has shown that [CuLH−1(H2O)](ClO4) is square pyramidal with a water molecule fixed in the apical position, one picolinamide moiety remaining uncoordinated (in agreement with ESR studies), whereas [NiLH−2] and [CoLH−2](ClO4)0.75Cl0.25 are both octahedral with the two pyridine rings in cis-positions. |
| Databáze: | OpenAIRE |
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