Juan Niclós

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 interaction of 2-methyllactic acid (H2mL) with divalent metal cations. The structures of (M(HmL)2(H2O)2), M /Mn(II), Zn(II)

Abstract The mononuclear complexes [M(HmL)2(H2O)2], where M=Mn(II) (1), Ni(II) (2) or Zn(II) (3) and HmL=2-methyllactato, were prepared and characterized by elemental analysis, FT-IR and UV/Vis spectroscopy and room temperature magnetic susceptibility measurements. Their thermal behaviour was also investigated, and compounds 1 and 3 were characterized by X-ray diffractometry. In both cases, the metal ion is hexacoordinated to two (O,O′)-bidentate monoanionic 2-methyllactato ligands and two aqua ligands in a distorted octahedral fashion. The [M(HmL)2(H2O)2] units are connected by hydrogen bonds, forming a two-dimensional network.

Synthesis and characterization of a potassium complex of magneson: [K(HL)(OH2)2]∞ [H2L=4-(4-nitrophenylazo)resorcinol (magneson)]

The synthesis and crystallographic, spectroscopic and thermal characterization of the potassium complex [K(HL)(OH2)2] [H2L=4-(4-nitrophenylazo)resorcinol (magneson)] are reported. In the solid state, the K + ion is heptacoordinated and the ligand binds with three different coordination modes (via a bidentate chelating nitro group, a bridging nitro oxygen and a phenolic oxygen), giving rise to a polymeric structure.

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-

Synthesis and structural characterization of the mixed ligand complex [Cu(HmL)2(phen)].2 H2O (H2mL = 2-methyllactic acid)

Abstract A new mixed-ligand complex of copper(II) with 1,10-phenanthroline and 2-methyllactate was prepared. [Cu(HmL)2(phen)] ·2H2O (where HmL = monodeprotonated 2-methyllactic acid) was characterized by elemental analysis, IR, electronic and EPR spectroscopy, magnetic measurements at room temperature, thermogravimetric analysis and X-ray diffractometry. The copper atom is in a tetragonally distorted octahedral environment and the 2-methyllactato ligand is bidentately chelating. The presence of lattice water molecules mediates the formation of a three-dimensional network.