Synthesis, crystal structure, weak antiferromagnetic behavior and electronic studies of novel [((-)-sparteine) (PhCO2)(Cl)]Cu(II) complex
[((-)-Sparteine)(PhCO2)(CI)]Cu(II) 1 Complex is obtained by direct synthesis using copper(0). 1 crystallizes in the monoclinic space group P2(1) with a = 14.7355(12), b = 8.9768(5), c = 17.28 10(10) Angstrom, beta = 111.916(5)degrees, and Z = 4. The electronic spectrum of 1 shows a broad band with l...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2003 |
| País: | México |
| Institución: | Universidad Nacional Autónoma de México |
| Repositorio: | Sistema de Información de la Facultad de Ciencias, UNAM |
| OAI Identifier: | oai:repositorio.fciencias.unam.mx:11154/1702 |
| Acceso en línea: | http://hdl.handle.net/11154/1702 |
| Access Level: | acceso abierto |
| Palabra clave: | Chemistry, Physical Cu(II)-complexes small antiferromagnetic exchange |
| Sumario: | [((-)-Sparteine)(PhCO2)(CI)]Cu(II) 1 Complex is obtained by direct synthesis using copper(0). 1 crystallizes in the monoclinic space group P2(1) with a = 14.7355(12), b = 8.9768(5), c = 17.28 10(10) Angstrom, beta = 111.916(5)degrees, and Z = 4. The electronic spectrum of 1 shows a broad band with lambda(max) similar to 841 nm (epsilon = 0.261 mM(-1) cm(-6)) characteristic of a low symmetry and tetragonally distorted square pyramidal local Cu geometry. The far IR spectrum of 1 shows characteristic vibrations of Cu-Cl (260, 267 cm(-1)), Cu-N (436, 467 cm(-1)) and Cu-O (457 cm(-1)) bonds. The H-1 NMR spectrum of 1 is typical of magnetic Cu(H) complexes with line broadening due to efficient nuclear relaxation from the metal center. ESR spectra of polycrystalline 1 at 77 K show an axial spectrum with linewidth of 58.6 G and at 300 K of 89.0 G, with areas in the ratio A(77)/A(300) = 2.79, indicative of antiferromagnetic order. The linewidth is reduced by 34% on going from 300 to 77 K. Standard magnetization measurements at low temperatures show an Curie-Weiss behavior with theta = -21.67 K, suggesting a weak exchange coupling interaction. The crystalline structure of I shows that the lattice is arranged so that the space between molecules is smaller than 40 Angstrom(3), not enough to accommodate solvent molecules. However, the shortest Cu-Cu contact is 7.5912(8) Angstrom. (C) 2003 Elsevier B.V. All rights reserved. |
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