Remarkable Inertness of Copper(II) Chelates of Cyclen-Based Macrobicycles with Two trans-N-Acetate Arms
Two cross-bridged cyclen-based macrocycles with two trans-N-acetic acid arms, one having a dibenzofuran (DBF) moiety as the bridge, H2L1, and the other a diphenyl ether (DPE) one, H2L2, were synthesized. Both compounds behave as "proton sponges." The thermodynamic stability constants for the Cu(2+), Zn(2+), Al(3+), and Ga(3+) complexes of both compounds were determined. They exhibit an excellent thermodynamic selectivity for copper(II), ensuring that metal ions largely present in the human body do not interfere with the copper(II) chelates. All complexes are very slow to form, and [CuL2] and [CuL1] are extremely inert to demetallate, especially [CuL2]. The acid-assisted dissociation of [CuL…
A Trinuclear Copper(II) Cryptate and Its μ3-CO3 Cascade Complex: Thermodynamics, Structural and Magnetic Properties
The 2,4,6-triethylbenzene-capped hexaamine macrobicycle with pyridyl spacers (pyr) was able to coordinate three copper(II) ions within its cavity. Potentiometric studies performed at 298.2 K in MeOH/H(2)O (50:50 v/v) and at ionic strength 0.10 mol dm(-3) in KNO(3) revealed that trinuclear species predominate in solution from pH 5.0, the hydroxo complexes being the main species, which start forming at unusual very low pH values. The single-crystal X-ray determination of the trinuclear complex showed that the three copper centres have square-planar geometry, arranged in an almost equilateral triangle, and have carbonate bridging the three metal centres. The presence of carbonate resulted from…
CCDC 924316: Experimental Crystal Structure Determination
Related Article: Catarina V. Esteves, Pedro Lamosa, Rita Delgado, Judite Costa, Pauline Désogère, Yoann Rousselin, Christine Goze, and Franck Denat|2013|Inorg.Chem.|52|5138|doi:10.1021/ic400015v
CCDC 907927: Experimental Crystal Structure Determination
Related Article: Catarina V. Esteves, Pedro Lamosa, Rita Delgado, Judite Costa, Pauline Désogère, Yoann Rousselin, Christine Goze, and Franck Denat|2013|Inorg.Chem.|52|5138|doi:10.1021/ic400015v