Copper(II) complexes of open-chain thioether ligands terminated by salicylaldimine functionality^*This article has a companion paper in this issue (doi: 10.1139/v11-081).

Abstract

From 1,11-bis(salicylaldimine)-3,6,9-trithiaundecane (H 2 L1), 1,11-bis(salicylaldimine)-6-oxa-3,9-dithiaundecane (H 2 L2), and 1,8-bis(salicylaldimine)-3,6-dithiaundecane (H 2 L3), syntheses for [Cu(L1)] 2 (I), Cu(L2)·CH 3 OH (II), Cu(L3) (III), [Cu(HL3)][CH 3 COO] (IV), [Cu(HL1-sal)]Cl 2 (V), Cu 4 (L1) 2 Br 4 (H 2 O) 2 ·2H 2 O (VI) and Cu 2 (L2)Br 2 ·xH 2 O (VII) are described. Single crystal X-ray structural studies for I, III and VII are reported. Variable temperature magnetic susceptibility studies of I, VI and VII are discussed. The examination of VII represents the first magneto-structural study of a binuclear copper(II) species with NSO3Br coordination spheres. This study examines perturbation by one or more of the donor atoms so that none of the known magnetostructural models predicts the copper-copper coupling.Résumé : Utilisant les 1,11-bis(salicylaldimine)-3,6,9-trithiaundécane (H2L1), 1,11-bis(salicylaldimine)-6-oxa-3,9-dithiaundécane (H2L2) et 1,8-bis(salicylaldimine)-3,6-dithiaundécane (H2L3), on a réalisé les synthèses des complexes [Cu(L1)]2 (I), Cu(L2)·CH3OH (II), Cu(L3) (III), [Cu(HL3)][CH3COO] (IV), [Cu(HLI-sal)]Cl2 (V), Cu4(L1)2Br5(H2O)2·2H2O (VI) et Cu2(L2)Br2·xH2O (VII). On a effectué la détermination des structures des composés I, III et VII par diffraction des rayons-X sur un cristal unique. On discute des résultats d'études de susceptibilité magnétique des composés I, VI et VII, à tempé-rature variable. L'examen du composé VII correspond à la première étude magnéto-structurale d'une espèce de cuivre(II) binucléaire comportant des sphères de coordination avec du NSO3Br. Cette étude permet d'examiner la perturbation par un ou plusieurs atomes donneurs; aucun des modèles magnéto-structuraux ne prédit le couplage cuivre-cuivre.Mots-clés : complexes de cuivre(II) binucléaire, thioéther, ligands salicylaldimine, susceptibilité magnétique à température variable, corrélation magnéto-structurale, structure par diffraction des rayons X.[Traduit par la Rédaction]

Against the Norm: Non Irving–Williams Transmetalation in Transition Metal Dimers

“…A search through the literature has revealed CuCu to have the largest ferromagnetic coupling for a Schiff base-derived normalC normalu 2 normalI normalI dimer to the best of our knowledge. The ferromagnetic exchange observed is unexpected based on previous magneto–structural correlations of O-bridged Cu II dimers, which consider only the Cu–O–Cu angles. − The Cu1–O–Cu2 angles in CuCu are 106.01(10)° and 105.22(10)° and would be expected to promote strong antiferromagnetic interactions based on this model, as shown by similar Schiff base-derived Cu II dimers. − Thus, as discussed by Ruiz and coworkers, other structural factors in CuCu including complex asymmetry, metal ion geometry, O–Cu–O–Cu torsion angles, the out-of-plane shift of the phenolato units, and the seven-coordinate Cu II ion should be considered. This will require detailed theoretical calculations, which are beyond the scope of this paper. Ĥ = prefix− 2 ∑ i < j J i j true s i 0em ̂ · true s j 0em ̂ …”