13 research outputs found
Synthesis, structure and magnetic properties of tetrakis-μ-carboxylato-bis(dodecylnicotinato)dicopper(II) complexes; crystal and molecular structure of the decyl carboxylate derivative
Dodecylnicotinate bis-adducts of binuclear copper carboxylates, of the general formula Cu2(O2CCn-1H2n-1)4(C 5H4NCOOC12H25)2, were synthesized for n = 10, 12, 14, 16, 18 and 20, and their crystal structure, thermal behavior and magnetic properties studied. The molecular structure of the decyl derivative has been determined from single-crystal X-ray diffraction data. The dimer is centrosymmetric with the CuII ions in a square-pyramidal coordination with four O-alkyl O atoms [average d(Cu - O) 1.960 (6) Å] in the basal plane and the nicotine N atom at apical positions [d(Cu - N) 2.183 (3) Å]. The copper ions, 2.615 (1) Å apart, are bridged by four O-alkyl carboxylate groups. Both the n = 20 and n = 18 homologues exhibit lamellar phases, which can be related to the supramolecular arrangement found in the n = 10 derivative. The magnetic behavior of the decyl and octadecyl dimers was studied in the 2-300 K temperature range. They exhibit a strong intramolecular antiferromagnetic interaction (Cu-Cu superexchange coupling constant J = -347 cm-1 for the decyl derivative), which can be attributed to a large overlap of the metal 3d orbitals and the oxygen lone pair orbitals of the linking carboxylate groups.Fil: Rusjan, Marcia. Universidad Nacional de General Sarmiento; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Chaia, Zulema. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Piro, Oscar Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Guillon, Daniel. Universite Paul Verlaine-Metz. Institut de Physique, Chimie et Materiaux; FranciaFil: Cukiernik, Fabio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidad Nacional de General Sarmiento; Argentin
A liquid crystal derived from ruthenium(II,III) and a long-chain carboxylate
The title compound, catena-poly[[tetrakis(μ-decanoato-κ2O:O′)diruthenium(II,III)(Ru—Ru)]-μ-octanesulfonato-κ2O:O′], [Ru2(C10H19O2)4(C8H17O3S)], is an octanesulfonate derivative of the mixed-valence complex diruthenium tetradecanoate. The equatorial carboxylate ligands are bidentate, bridging two Ru atoms to form a dinuclear structure. Each of the two independent dinuclear metal complexes in the asymmetric unit is located at an inversion centre. The octanesulfonate anion bridges the two dinuclear units through axial coordination. The alkyl chains of the carboxylate and sulfonate ligands are arranged in a parallel manner. The global structure can be seen as infinite chains of polar moieties separated by a double layer of non-polar alkyl groups, without interdigitation of the alkyl chains.Facultad de Ciencias Exacta
A pyrazine bis-adduct of a binuclear rhodium(II) carboxylate containing 3,4,5-triethoxybenzoate as the equatorial ligand
The title compound, tetrakis(μ-3,4,5-triethoxybenzoato-κ2O:O′)bis[(pyrazine-κN)rhodium(II)](Rh—Rh), [Rh2(C13H17O5)4(C4H4N2)2], crystallizes on an inversion centre in the triclinic space group P ‾1. The equatorial carboxylate ligands bridge the two RhII atoms, giving a binuclear lantern-like structure. The pyrazine molecules occupy the two axial coordination sites. The phenyl rings are tilted by ca 10° with respect to the attached carboxylate groups. The pyrazine planes have a torsion angle of ca 19° around the Rh—N bond with respect to the plane of the nearer carboxylate group and are not coplanar with the Rh—Rh bond.Instituto de Física La Plat
Síntesis y estudios fisicoquímicos de cristales líquidos moleculares derivados de rutenio y cobre
El crecimiento exponencial de los avances tecnológicos actuales impulsa la sintesis de materiales moleculares con propiedades fisicoquimicas bien determinadas. Esto ha incentivado el desarrollo de nuevos compuestos con propiedades cristal líquido conteniendo metales de transición. Cuatro grupos de metalomesógenos se estudian en este trabajo, con el propósito de lograr mesofases estables a baja temperatura y caracterizar dichas fases desde el punto de vista estructural. La combinación de diferentes ligandos ecuatoriales y axiales se analizó en tres series de carboxilatos binucleares de rutenio de valencia mixta: Ru2(Cn),DOS, Ru2(B2OCn),DOS y Ru2(B3OCn), Cl. Además, se estudió la influencia de la introducción de ligandos voluminosos en una serie de complejos de cobre:Cu2(B3OCn). Se logró descender la temperatura de transición hacia la mesofase, respecto de los compuestos previamente estudiados por otros autores haciendo uso del principio del llenado eficaz del espacio intermolecular. De esta manera se logró obtener mesofases aún a temperatura ambiente en ciertos complejos de rutenio. La aparición de mesofases cúbicas en algunos de estos compuestos contribuye a la diversificación de la geometria molecular: a la vez que permite establecer nexos másfuertes entre compuestos termotrópicos y liotrópicos. Sobre la base de experimentos de difracción de rayos-X y con la ayuda de técnicas complementarias utilizadas como sondas locales, se propone en cada caso un modelo estructural adecuado.The exponential growth of technological advances pushed up the synthesis of molecular materials exhibiting special physicochemical properties. This fact increased the development of new compounds showing liquid crystal behaviuor and containing transition metal atoms. In the present work four series of metallomesogens have been studied. with the aim of stabilizing low temperature mesophases in order to overcame a structural analysis. The combination of different equatorial and axial ligands was studied in the following series of ruthenium dinuclear mixed valence carboxylates: Ru2(Cn),DOS. Ru2(B2OCn),DOS and Ru2(B3OCn),Cl. Also, the influence of the introduction of bulky ligands in the copper complexes of the series Cu2(B3OCn),was analysed . A decrease in the transition temperature to the mesophase was achieved exploiting the principle of the intermolecular space filling. Thus even room temperature mesophases were obtained for some ruthenium complexes. Cubic mesophases appearance contribute to the diversification of the geometry and rise on a renewed link between thermotropic and lyotropic compounds. A structural model is proposed in each of the series on a basis of X-ray diffraction experiments and other complimentary techniques used as local probes.Fil:Chaia, Zulema Débora. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Structural Characterization of the Mesophases Exhibited by Dicopper and Diruthenium Trialkyloxybenzoates
Synthesis, structure and magnetic properties of tetrakis-μ-carboxylato-bis(dodecylnicotinato)dicopper(II) complexes; crystal and molecular structure of the decyl carboxylate derivative
Dodecylnicotinate bis-adducts of binuclear copper carboxylates, of the general formula Cu2(O2CCn-1H2n-1)4(C5H4NCOOC12H25)2, were synthesized for n = 10, 12, 14, 16, 18 and 20, and their crystal structure, thermal behavior and magnetic properties studied. The molecular structure of the decyl derivative has been determined from single-crystal X-ray diffraction data. The dimer is centrosymmetric with the CuII ions in a square-pyramidal coordination with four O-alkyl O atoms [average d(Cu - O) 1.960 (6) Å] in the basal plane and the nicotine N atom at apical positions [d(Cu - N) 2.183 (3) Å]. The copper ions, 2.615 (1) Å apart, are bridged by four O-alkyl carboxylate groups. Both the n = 20 and n = 18 homologues exhibit lamellar phases, which can be related to the supramolecular arrangement found in the n = 10 derivative. The magnetic behavior of the decyl and octadecyl dimers was studied in the 2-300 K temperature range. They exhibit a strong intramolecular antiferromagnetic interaction (Cu-Cu superexchange coupling constant J = -347 cm-1 for the decyl derivative), which can be attributed to a large overlap of the metal 3d orbitals and the oxygen lone pair orbitals of the linking carboxylate groups.Facultad de Ciencias ExactasInstituto de Física La Plat
N-nitrosomelatonin
The title compound, N-[2-(5-methoxy-1-nitroso-1H-indol-3-yl)ethyl]acetamide, C13H15N3O3, an N-nitroso derivative of melatonin, crystallizes in the monoclinic C2/c space group. The molecules are arranged in such a way that the aromatic rings are in a planar conformation, with the alkylamide side chains in a different plane, at a dihedral angle of 108.60 (6)°. The alkylamide chains are interconnected by hydrogen bonds, constituting an infinite array.Facultad de Ciencias Exacta
N-nitrosomelatonin
The title compound, N-[2-(5-methoxy-1-nitroso-1H-indol-3-yl)ethyl]acetamide, C13H15N3O3, an N-nitroso derivative of melatonin, crystallizes in the monoclinic C2/c space group. The molecules are arranged in such a way that the aromatic rings are in a planar conformation, with the alkylamide side chains in a different plane, at a dihedral angle of 108.60 (6)°. The alkylamide chains are interconnected by hydrogen bonds, constituting an infinite array.Facultad de Ciencias Exacta
N-nitrosomelatonin
The title compound, N-[2-(5-methoxy-1-nitroso-1H-indol-3-yl)ethyl]acetamide, C13H15N3O3, an N-nitroso derivative of melatonin, crystallizes in the monoclinic C2/c space group. The molecules are arranged in such a way that the aromatic rings are in a planar conformation, with the alkylamide side chains in a different plane, at a dihedral angle of 108.60 (6)°. The alkylamide chains are interconnected by hydrogen bonds, constituting an infinite array.Facultad de Ciencias Exacta
A liquid crystal derived from ruthenium(II,III) and a long-chain carboxylate
The title compound, catena-poly[[tetrakis(μ-decanoato- κ2O:O′)-diruthenium(II, III) (Ru - Ru)]- μ-octanesulfonato-κ2O:O′], [Ru2(C10H19O2)4 (C8H17O3S)], is an octanesulfonate derivative of the mixed-valence complex diruthenium tetradecanoate. The equatorial carboxylate ligands are bidentate, bridging two Ru atoms to form a dinuclear structure. Each of the two independent dinuclear metal complexes in the asymmetric unit is located at an inversion centre. The octanesulfonate anion bridges the two dinuclear units through axial coordination. The alkyl chains of the carboxylate and sulfonate ligands are arranged in a parallel manner. The global structure can be seen as infinite chains of polar moieties separated by a double layer of non-polar alkyl groups, without interdigitation of the alkyl chains.Fil:Zelcer, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Chaia, Z.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Cukiernik, F.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina