Susana Balboa

Solid state coordination chemistry of copper(II)/α-hydroxycarboxylato/2,2′-bipyridine systems

Abstract Four new two-ligand complexes of copper(II) with 2,2′-bipyridine and one of three different α-hydroxycarboxylic acids (lactic, H2LACO; 2-methyllactic, H2MLACO; and mandelic, H2MANO) were prepared. Complexes 1–3 of general formula [Cu(HL)2(bipy)]·nH2O (HL=monodeprotonated acid), were characterized by elemental analysis, IR, electronic and EPR spectroscopy, magnetic measurements and thermogravimetric analysis. Complexes 1 (HL=HLACO, n=2), 2 (HL=HMLACO, n=1) and 3a (the result of attempted recrystallization of 3, of formula [Cu(HMANO)(bipy)2](HMANO)·H2MANO·CH3CN were studied by X-ray diffractometry. The copper atom is in an elongated, tetragonally distorted octahedral environment in 1 and 2 and in 3a has a coordination polyhedron intermediate between a square pyramid and a trigonal bipyramid, as evaluated in terms of the parameter τ. In 1 and 2 the α-hydroxycarboxylato ligand is bidentate and monoanionic but in 3a there are three forms: a monodentate monoanion, a monoanionic counterion, and a neutral molecule.

Supramolecular architectures of neutral and cationic complexes of transition metals with lactate and 1,10-phenanthroline

The following molecular complexes of transition metals MII with lactato (HL) and 1,10-phenanthroline (phen) ligands were prepared and characterized structurally: [M(HL)2(phen)]·nH2O, MII = Mn, Co, Ni, Cu, Zn; 1–6), [M(HL)(H2O)2(phen)]Cl, (MII = Mn, Co, Ni; 7–9), and [Ni(HL)(H2O)2(phen)]Br (10). These neutral and cationic octahedral complexes have 3-D supramolecular architectures due to weak noncovalent interactions. In the halide compounds, C–H⋯X− hydrogen bonds play a key role in the stabilization of the 3-D network.

The Crystal Structures of two Linearly Polymeric Copper(II) Complexes of 2, 2′-Bipyridine with threefold Glycolato and Oxalato Bridges†

The complex [Cu(HGLYO)2(bipy)] (I) and two new copper(II) coordination polymers with the formulas {[Cu(GLYO)1x(ox)x(bipy)]·2.5H2O}n [GLYO glycolato dianion, ox oxalato dianion, bipy 2,2 -bipyridine, x 0.56 (in II) or 0.71 (in III)] were synthesized using copper(II) glycolate as starting material and were characterized by IR, UV-Vis and EPR spectrometry, by magnetic measurements (II and III), and by single-crystal X-ray diffractometry. Both II and III crystallized as one-dimensional polymers composed of Cu2O2-centred dimers with a Cu-Cu distance of 3.282(1) A (mean of II and III) that are linked by Cu2(OCO)2 rings Die Kristallstrukturen von zwei linear-polymeren Kupfer(II)-Komplexen des 2,2 -Bipyridins mit dreifachen Glycolatund Oxalat-Brucken Inhaltsubersicht. Der Komplex [Cu(HGLYO)2(bipy)] (I) und die zwei neuen Kupfer(II)-Koordinationspolymere der Formel {[Cu(GLYO)1-x(ox)x(bipy)]·2.5H2O}n [GLYO Glycolat-Dianion, ox Oxalat-Dianion, bipy 2,2 -Bipyridine, x 0,56 (in II) or 0,71 (in III)] wurden ausgehend von Kupfer(ii)-glycolat synthetisiert und durch IR-, UV-Visund EPR-spektroskopische Messungen, durch magnetische Messungen (II und III) sowie durch Rontgen-Einkristallstrukturanalysen charakterisiert. II und III kristallisieren als eindimensionale Polymere aus Cu2O2-zentrierten Dime-

Chiral and achiral 1D copper(II) coordination polymers based on glycolato and chelating aromatic diamine ligands

Achiral glycolic acid and chelating aromatic diamine ligands were employed at room temperature to prepare five 1D copper(II) coordination polymers which were structurally characterized. The polymers ∞1{[Cu(HG)(dipyam)](HG)} (1) (dipyam = 2,2′-dipyridylamine) and ∞1[Cu(HG)(ClO4)(NN)] (NN = 2,2′-bipyridine (2), NN = 1,10-phenanthroline (3)) adopt homochiral helical structures in the crystal state and undergo spontaneous chiral resolution in the solid state. On the other hand, the polymers containing bidepronated glycolato ligand G, ∞1{[Cu(G)(dipyam)]·H2O} (1a), obtained from a solution of 1 in MeOH/iPrOH and ∞1{[Cu2(μ-G)(ClO4)(H2O)(dipyam)2](ClO4)(H2O)2} (4b) are achirals. Crystals of 4b have been obtained together with crystals of the molecular complex [Cu(HG)(H2O)(dipyam)](ClO4) (4a). Analysis by Hirshfeld surface generation and two-dimensional fingerprinting was carried out to study the nature of the interactions and their contributions towards the crystal packing.