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

Jubert, Caroline; Mohamadou, Aminou; Gérard, Christian; Brandès, Stéphane; Tabard, Alain; Barbier, Jean‐Pierre

doi:10.1039/b111614b

Cited by 48 publications

(29 citation statements)

References 52 publications

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“…They can act as bidentate ligands, as evidenced in the solid-state structure of a Cu II salt [22] or by molecular modelling [23] on lanthanide complexes, where both the pyridine N and the carbonyl oxygen atoms are coordinated to the metal ion. Alternatively, examples of picolinamides acting as monodentate ligands (through the pyridine nitrogen) [24] or, under basic conditions, as bidentate ligands through the deprotonated amide NH rather than the carbonyl group [25] are also known. We report herein our efforts to introduce picolinamide ligands on calixarene scaffolds in order to study whether the size of the macrocycle, the cooperation and the stereochemical disposition of these binding groups affect the efficiency of extraction and selectivity in the An/Ln separation.…”

Section: Introductionmentioning

confidence: 99%

Calixarene‐Based Picolinamide Extractants for Selective An/Ln Separation from Radioactive Waste

et al. 2005

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Section: Introductionmentioning

confidence: 99%

Calixarene‐Based Picolinamide Extractants for Selective An/Ln Separation from Radioactive Waste

et al. 2005

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“…3 (atm N 2 )) [15]. After 10 days air exposition, the Co/Pro system is characterized by a maximum absorption wavelength at 546 nm (e = 69 mol À1 L cm À1 ), which could be attributed to an octahedral Co III complex with probably remaining Co II complex as minority species [16]. The capacity of the oxygen consumption as a function of time was measured using an Oxymeter (Rank Brothers Ltd.) for various concentration of Co(II)(L-proline) 2 (H 2 O) 2 aqueous solution (Fig.…”

Section: Introductionmentioning

confidence: 99%

Co(II)(l-proline)2(H2O)2 solid complex: Characterization, magnetic properties, and DFT computations. Preliminary studies of its use as oxygen scavenger in packaging films

Damaj

Naveau

Dupont

et al. 2009

Inorganic Chemistry Communications

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“…In cation A, the Co-N3 bond distance (1.889 Å ) is significantly shorter than the Cu-N py bond distances (1.983 and 1.986 Å ) indicating that the deprotonated N3 atom of isoindoline is strongly coordinated to cobalt(III). The average Co-N py bond length of 1.984 Å is in the range found for the related [CoL(OBz)(OO-t-Bu)]complexes [49,50]. The N5-Co-N1 (177.2°) and N3-Co-N3 (176.3°) bond angles are very close to the ideal angle of 180°indicating that the planar ligand avoids severe distortions around Co(III).…”

Section: Description Of the Structure Of [Col 2 ](Clo 4 ) Ae Meoh (1)mentioning

confidence: 54%

Synthesis, structure and DNA interaction of cobalt(III) bis-complexes of 1,3-bis(2-pyridylimino)isoindoline and 1,4,7-triazacyclononane

Selvi

Stœckli-Evans

Palaniandavar

2005

Journal of Inorganic Biochemistry

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The complex [CoL 2 ](ClO 4 ) AE MeOH (1), where HL is the tridentate 3N ligand 1,3-bis(2-pyridylimino)isoindoline, has been isolated and its X-ray crystal structure successfully determined. It possesses a distorted octahedral structure in which both the ligands are coordinated meridionally to cobalt(III) via one deprotonated isoindoline (L À ) and two pyridine nitrogen atoms. Interestingly, the average dihedral angle between pyridine and isoindoline rings is 25.9°, indicating that the ligand is twisted upon coordination to cobalt(III). The interaction of the complex with calf-thymus DNA has been studied using various spectral methods and viscosity and electrochemical measurements. For comparison, the DNA interaction of [Co(tacn) 2 ]Cl 3 (2), where tacn is facially coordinating 1,4,7-triazacyclononane, has been also studied. The ligand-based electronic spectral band of 1 and the N(r) ! Co(III) charge transfer band of 2 exhibit moderate hypochromism with small or no blue shift on interaction with DNA. The intrinsic binding constants calculated reveal that the monopositive complex ion [CoL 2 ] + exhibits a DNA-binding affinity lower than the tripositive complex ion [Co(tacn) 2 ] 3+ . The steric clashes with DNA exterior caused by the second L À ligand bound to cobalt(III), apart from the lower overall positive charge on the [CoL 2 ] + complex, dictates its DNA-binding mode to be surface binding rather than partial intercalative interaction expected of the extended aromatic chromophore of deprotonated isoindoline anion. An enhancement in relative viscosity of CT DNA on binding to 1 is consistent with its DNA surface binding. On the other hand, a slight decrease in viscosity of CT DNA was observed on binding to 2 revealing that the smaller cation leads to bending (kinking) and hence shortening of DNA chain length. The electrochemical studies indicate that the DNA-bound complexes are stabilised in the higher Co(III) rather than the lower Co(II) oxidation state, suggesting the importance of electrostatic forces of DNA interaction.

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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

Cited by 48 publications

References 52 publications

Calixarene‐Based Picolinamide Extractants for Selective An/Ln Separation from Radioactive Waste

Calixarene‐Based Picolinamide Extractants for Selective An/Ln Separation from Radioactive Waste

Co(II)(l-proline)2(H2O)2 solid complex: Characterization, magnetic properties, and DFT computations. Preliminary studies of its use as oxygen scavenger in packaging films

Synthesis, structure and DNA interaction of cobalt(III) bis-complexes of 1,3-bis(2-pyridylimino)isoindoline and 1,4,7-triazacyclononane

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