The crystal structure and magnetic properties of 3-pyridinecarboxylate-bridged Re(ii)M(ii) complexes (M = Cu, Ni, Co and Mn)

Dublin Core

Título

The crystal structure and magnetic properties of 3-pyridinecarboxylate-bridged Re(ii)M(ii) complexes (M = Cu, Ni, Co and Mn)

Tema

QUIMICA INORGANICA
COBRE
COMPLEJOS
BIBLIOGRAFIA NACIONAL QUIMICA
2015

Abstract

The novel Re(II) complex NBu4[Re(NO)Br4(Hnic)] (1) and the heterodinuclear compounds [Re(NO)Br4(μ-nic)Ni(dmphen)2]·½CH3CN (2), [Re(NO)Br4(μ-nic)Co(dmphen)2]·½MeOH (3), [Re(NO)Br4(μ-nic)Mn(dmphen)(H2O)2]·dmphen (4), [Re(NO)Br4(μ-nic)Cu(bipy)2] (5) [Re(NO)Br4(μ-nic)Cu(dmphen)2] (5′) (NBu4+ = tetra-n-butylammonium cation, Hnic = 3-pyridinecarboxylic acid, dmphen = 2,9-dimethyl-1,10-phenanthroline, bipy = 2,2′-bipyridine) have been prepared and the structures of 1–5 determined using single crystal X-ray diffraction. The structure of 1 consists of [Re(NO)Br4(Hnic)]− anions and NBu4+ cations. Each Re(II) is six-coordinate with four bromide ligands, a linear nitrosyl group and a nitrogen atom from the Hnic molecule, in a distorted octahedral surrounding. The structures of 2–5 are made up of discrete heterodinuclear Re(II)M(II) units where the fully deprotonated [Re(NO)Br4(nic)]2− entity acts as a didentate ligand through the carboxylate group towards the [Ni(dmphen)2]2+ (2), [Co(dmphen)2]2+ (3), [Mn(dmphen)(H2O)2]2+ (4) and [Cu(bipy)2]2+ (5) fragments, the Re–M separation across the nic bridge being 7.8736(8) (2), 7.9632(10) (3), 7.7600(6) (4) and 8.2148(7) Å (5). The environment of the Re(II) ion in 2–5 is the same as that in 1 and all M(II) are six-coordinate in highly distorted octahedral surroundings, the main source of the distortion being due to the reduced bite of the chelating carboxylate. The magnetic properties of 1–5′ were investigated in the temperature range 1.9–300 K. 1 behaves as a quasi-magnetically isolated spin doublet with very weak antiferromagnetic interactions through space Br⋯Br contacts. Its magnetic susceptibility data were successfully modeled through a deep analysis of the influence of the ligand field, spin–orbit coupling, tetragonal distortion and covalence effects as variable parameters. Compounds 2–5′ exhibit weak antiferromagnetic interactions. The intramolecular exchange pathway in this family being discarded because of the symmetry of magnetic orbitals of the Re(II) ion (dxy) precludes any spin delocalization on the bridging nic orbitals, the observed magnetic interactions are most likely mediated by π–π type interactions between the peripheral ligands which occur in them. Only in the case of 4, short through space Br⋯Br contacts of ca. 4.03 Å (values larger than 5.5 Å in 2, 3 and 5) could be involved in the exchange coupling.

Autor

Pacheco, Mario
González-Platas, Javier
Lloret, Francesc
Julve, Miguel

Fuente

Dalton Transactions v. 44, no. 25, 2015. -- p. 11636-11648

Editor

Royal Society of Chemistry

Fecha

2015

Derechos

Información sobre Derechos de Autor

(Por favor lea este aviso antes de abrir los documentos u objetos)

La legislación uruguaya protege el derecho de autor sobre toda creación literaria, científica o artística, tanto en lo que tiene que ver con sus derechos morales, como en lo referente a los derechos patrimoniales con sujeción a lo establecido por el derecho común y las siguientes leyes

(LEY 9.739 DE 17 DE DICIEMBRE DE 1937 SOBRE PROPIEDAD LITERARIA Y ARTISTICA CON LAS MODIFICACIONES INTRODUCIDAS POR LA LEY DE DERECHO DE AUTOR Y DERECHOS CONEXOS No. 17.616 DE 10 DE ENERO DE 2003, LEY 17.805 DE 26 DE AGOSTO DE 2004, LEY 18.046 DE 24 DE OCTUBRE DE 2006 LEY 18.046 DE 24 DE OCTUBRE DE 2006)

ADVERTENCIA - La consulta de este documento queda condicionada a la aceptación de las siguientes condiciones de uso: Este documento es únicamente para usos privados enmarcados en actividades de investigación y docencia. No se autoriza su reproducción con fines de lucro. Esta reserva de derechos afecta tanto los datos del documento como a sus contenidos. En la utilización o cita de partes debe indicarse el nombre de la persona autora.

Formato

PDF

Idioma

Inglés

Tipo

Artículo

Identificador

DOI: 10.1039/C5DT01321F

Document Item Type Metadata

Original Format

PDF
Fecha de agregación
March 10, 2016
Colección
Bibliografía Nacional Química
Tipo de Elemento
Document
Etiquetas
, ,
Citación
Pacheco, Mario, “The crystal structure and magnetic properties of 3-pyridinecarboxylate-bridged Re(ii)M(ii) complexes (M = Cu, Ni, Co and Mn),” RIQUIM - Repositorio Institucional de la Facultad de Química - UdelaR, accessed September 26, 2020, http://riquim.fq.edu.uy/items/show/3746.
Archivos