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Cabort, Amel

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Cabort, Amel
Affiliation principale
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https://libra.unine.ch/handle/123456789/389

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  • Publication
    Métadonnées seulement
    Iron, cobalt, nickel and ruthenium complexes of 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine, a pybox analogue
    (2003)
    Cabort, Amel 
    ;
    Michel, Armelle
    ;
    Therrien, Bruno 
    ;
    Stoeckli-Evans, Helen 
    ;
    Bernauer, Klaus
    ;
    Süss-Fink, Georg 
    ;
    Williams, Alan F.
    ;
    Stupka, Gilles
    The coordination of 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine (L) to Ni, Ru, Fe, and Co was studied. The reaction with Ni salts gives the Ni(II) complex [Ni(L)2]2+ (1). The reaction of RuCl3 gives only the Ru(II) complex [Ru(L)2]2+ (2). In the case of Fe, both [Fe(L)2]2+ (3) and [Fe(L)2]3+ (4) were synthesized and characterized. In the case of Co, the Co(III) complex [Co(L)2]3+ (5) was obtained, even if a Co(II) salt was used. However, [Co(L)2]2+ (6) can be obtained under N. Mol. structures of 1-5 complexes were detd. by x-ray anal. of the corresponding perchlorate salts; the structure of 3 was solved for both the perchlorate and the tetrachloroferrate(III) salts. All complexes show an octahedral coordination geometry with meridional arrangement of the two tridentate ligands. The electrochem. behavior of 2, 3 and 6 was studied by cyclic voltammetry. Quasi reversible electron transfer is obsd. for the redox pairs FeIII/FeII and CoII/CoI. The reaction shows somewhat weaker reversibility for CoIII/CoII, whereas the reaction of RuIII/RuII is not reversible. The measurements suggest 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine (L) to have a higher stabilization of low-valent oxidn. states of Fe and Co than terpyridine. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Copper(II) azido complexes containing trinitrogen ligands: [Cu(?3-L)(N3)]2[Cu2Cl2(N3)4] [L = 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine], a tridimensional network of cationic and anionic copper complexes
    (2003)
    Cabort, Amel 
    ;
    Therrien, Bruno 
    ;
    Bernauer, Klaus
    ;
    Süss-Fink, Georg 
    Copper(II) azido complexes contg. a tridentate trinitrogen ligand, [Cu(?3-L)(N3)]+ [L = 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine] as well as [Cu(?3-R,S-LH4)(N3)]+, [Cu(?3-S,S-LH4)(N3)]+ and [Cu(?3-R,R-LH4)(N3)]+ [LH4 = 2,6-bis(pyrrolidin-2-yl)pyridine] were synthesized from Cu(ClO4)2·6H2O, NaN3 and the corresponding tridentate ligand and crystd. from methanol as the perchlorate salts. The single crystal x-ray structure analyses show these complexes to form 1-dimensional networks by Cu···N(azide) intermol. interactions, depending on the conformation of the tridentate ligand. In the case of L, an excess of sodium azide gives [Cu(?3-L)(N3)]2[Cu2Cl2(N3)4], the crystal structure anal. of which reveals a surprising tridimensional network of cationic and anionic copper(II) complexes linked by Cu···N(azide) and Cu···N(L) interactions. [on SciFinder(R)]
  • Publication
    Accès libre
    Carbonate binding to copper(II) in solution: mixed-ligand complex formation and its application to the isolation and separation of the three isomers of [Cu(bpp)(H2O)][ClO4]2 [bpp = 2,6-bis(pyrrolidin-2-yl)pyridine]
    (2002)
    Bernauer, Klaus
    ;
    Godefroy, Isabelle
    ;
    Cabort, Amel 
    ;
    Guicher, Nathalie
    ;
    Stoeckli-Evans, Helen 
    ;
    Süss-Fink, Georg 
    The binding of the carbonate anion to [Cu(meso-bpp)(H2O)]2+ and rac-[Cu(bpp)(H2O)]2+ [bpp = 2,6-bis(pyrrolidin-2-yl)pyridine] in aqueous solution has been investigated. Formation constants of the carbonato complexes [Cu(meso-bpp)(CO3)] and rac-[Cu(bpp)(CO3)] (1.02 × 103 M–1 and 1.77 × 103 M–1, respectively, µ= 0.70 M) have been calculated from spectrophotometric measurements. The formation of these Cu2+ complexes can also be used for an improved synthesis and an easy isolation of the three diastereoisomers of bpp. The mixture of [Cu(meso-bpp)(H2O)]2+ and rac-[Cu(bpp)(H2O)]2+ is separated by elution from SP Sephadex C-25, either as hydroxo or carbonato derivatives. rac-[Cu(bpp)(H2O)]2+ is then resolved into the enantiomers [Cu(S,S-bpp)(H2O)]2+ and [Cu(R,R-bpp)(H2O)]2+, again on SP Sephadex C-25, by means of L-(+)-tartrate as chiral eluent. The three stereoisomers, meso-bpp, (S,S)-bpp and (R,R)-bpp are liberated from the corresponding copper(II) complexes by ligand displacement using trans-1,2-diaminocyclohexane-N,N,N’,N’-tetraacetic acid (H4cdta). The structure of the meso isomer was solved by a single crystal X-ray analysis using the perchlorate salt [meso-bppH2][ClO4]2•2H2O.
  • Publication
    Métadonnées seulement
    Ligand dehydrogenation in ruthenium trinitrogen complexes: synthesis, structure and chirality of the cations [Ru(LH4)(L)]2+ [LH4 = 2,6-bis(pyrrolidin-2-yl)pyridine]
    (2002)
    Cabort, Amel 
    ;
    Therrien, Bruno 
    ;
    Stoeckli-Evans, Helen 
    ;
    Bernauer, Klaus
    ;
    Süss-Fink, Georg 
    Reaction of 2,6-bis(pyrrolidin-2-yl)pyridine (LH4) with RuCl3·3H2O in refluxing MeOH/H2O mixts. gives the octahedral complexes [Ru(LH4)(L)]2+, in which one of the two trihapto ligands was dehydrogenated as 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine (L), even if LH4 was present in excess. With the three stereoisomers of LH4, [Ru(R,S-LH4)(L)]2+ (meso), [Ru(R,R-LH4)(L)]2+ and [Ru(S,S-LH4)(L)]2+ were isolated as the perchlorate salts and characterized by x-ray structure anal. and by CD spectra. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
  • Publication
    Métadonnées seulement
    [2,6-Bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine]trichlororhodium(III) dibenzene solvate
    (2002)
    Cabort, Amel 
    ;
    Therrien, Bruno 
    ;
    Bernauer, Klaus
    ;
    Süss-Fink, Georg 
    Crystals of the title compd. are monoclinic, space group C2/c, with a 11.434(2), b 10.630(2), c 20.948(4) Å, ? 100.12(3)°; Z = 4, dc = 1.534; R = 0.026, Rw(F2) = 0.059 for 2341 reflections. The structure of the mononuclear octahedral Rh(III) complex possesses a 2-fold axis passing through Rh, the equatorial Cl atom and the N atom pyridine ring. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    [RuCl{2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine}(PPh3)2]BF4 dichloromethane solvate
    (2002)
    Cabort, Amel 
    ;
    Therrien, Bruno 
    ;
    Bernauer, Klaus
    ;
    Süss-Fink, Georg 
    The tetrafluoroborate salt of the mononuclear octahedral Ru(II) complex, [RuCl(L)(PPh3)2]BF4, where L = 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine, was prepd. as the CH2Cl2 solvate. Crystals are triclinic, space group P?1, with a 10.3368(8), b 12.7939(11), c 19.1336(16) Å, ? 80.231(10), ? 89.193(9), ? 67.943(9)°; Z = 2, dc = 1.505; R = 0.031, Rw(F2) = 0.076 for 8322 reflections. The PPh3 ligands adopt a trans configuration, with a P-Ru-P angle of 173.72(2)°. [on SciFinder(R)]
  • Publication
    Accès libre
    Etude de ligands triamines tridentés de type bis(pyrrol)pyridine pour la coordination aux métaux de transition
    (2002)
    Cabort, Amel 
    ;
    Süss-Fink, Georg 
    Ce travail de thèse a porté sur l'étude de la coordination aux métaux de transition des composés triamines tridenté suivants : la 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine (L) et la 2,6-bis(pyrrolidin-2-yl)pyridine (LH4). Dans un premier temps, nous avons synthétisé des complexes de type [M(L)2]2+ (M = Ni, Ru, Co et Fe) et [M(L)2]3+ (M = Co et Fe) dont nous avons étudié les propriétés d'oxydoréduction par voltamétrie cyclique. Cette étude électrochimique nous a permis de montrer que la coordination du ligand L stabilisait les bas degrés d'oxydation du cobalt et du fer. Par ailleurs, nous avons obtenu des complexes de ruthénium [Ru(PPH3)(L)Cl] (7) et de rhodium [Rh(L)Cl3] contenant une seule unité L. Consernant la triamine LH4, nous avons tout d'abord séparé ses trois stéréoisomères, (R,S)-LH4, (R,R)-LH4 et (S,S)-LH4, par une élégante chromatographie sur résine échangeuse de cations via les aqua-complexes de cuivre [Cu(LH4)(H2O)]2+. L'étude de la coordination des stéréoisomères de LH4, nous a alors permis d'obtenir de surprenants complexes de ruthénium [Ru(LH4)(L)] qui contiennent un ligand di-amine LH4 et un ligand di-imine L résultant de la déshydrogénation de LH4. Pour finir nous avons aussi synthétisé des azotures de cuivre [Cu(LH4)(N3)]+