Options
Cabort, Amel
Nom
Cabort, Amel
Affiliation principale
Identifiants
Résultat de la recherche
Voici les éléments 1 - 4 sur 4
- PublicationMétadonnées seulementIron, cobalt, nickel and ruthenium complexes of 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine, a pybox analogue(2003)
; ;Michel, Armelle; ; ;Bernauer, Klaus; ;Williams, Alan F.Stupka, GillesThe 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)] - PublicationMétadonnées seulementLigand 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)
; ; ; ;Bernauer, KlausReaction 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)] - PublicationMétadonnées seulementLigand dehydrogenation in ruthenium trinitrogen complexes: synthesis, structure and chirality of the cations [Ru(LH4)(L)]2+ [LH4=2,6-bis(pyrrolidin-2-yl)pyridine]. [Erratum to document cited in CA138:116799](2002)
; ; ; ;Bernauer, KlausIn Scheme 1, the N atom was missing at several places; the cor. scheme is given. [on SciFinder(R)] - PublicationAccès libreCarbonate 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; ;Guicher, Nathalie; 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.