Autor según el artículo: De Graaf, C. ; Maxim, C. ; Saureu, S. ; Ferlay, S. ; Wais, M. ; Robert, V.; Train, C.

Departamento: Química Física i Inorgànica

Autor/es de la URV: DE GRAAF , CORNELIS; Maxim, C. ; Saureu, S. ; Ferlay, S. ; Wais, M. ; Robert, V.; Train, C.

Palabras clave: Manganese Magnetic properties Ab initio calculations

Resumen: Three X2+ bisamidinium dications are used as template for the formation of oxalate-based bimetallic [MnCr] compounds 1-3 of formula X[MnII(CH3OH)CrIII(ox)3]2·nS (X2+ = C14N4H20 2+ (cation A, compound 1), C14O2N4H202+ (cation B, compound 2), C16N4H24 2+ (cation C, compound 3); n=4 (1-2), 2 (3); S= CH3OH (1-2), CH3CN (3)). The single-crystal X-rays analysis reveals that in 1-3, a Mn-Cr oxalate-bridged bimetallic coordination network is formed, displaying corrugated two-dimensional (2D) layers based on heptacoordinated manganese(II) ions, with six oxygen atoms from three bis(bidentate) oxalate ions and one oxygen atom from a coordinated methanol molecule in the coordination sphere. In all cases, the coordination environment of manganese(II) is close to a Capped Trigonal PRism (CTPR). This evolution is related to the disymmetrization of one of the three oxalate linkages. Measurements of the magnetic properties revealed a continuous increase of the χ MT product, where χ M is the magnetic susceptibility, when the temperature is lowered from 300K to 5K, indicating the presence of a dominant ferromagnetic interaction in 1-3. The Curie-Weiss temperatures deduced from the fit of the magnetic susceptibility in the paramagnetic phase are 5.87K, 4.40K and 3.98K for 1, 2 and 3 respectively. From a mean field approach, an average weak ferromagnetic exchange interaction of 0.62K, 0.42K and 0.54K respectively can be deduced. Ab initio calculations up to the DDCI-2 level were performed on [MnCr] dimeric units. They allow to evaluate the exchange interaction for each type of bridges present in the three compounds. An effect of the asymmetry of the bridge on the exchange interaction is observed but not in a systematic way.

Grupo de investigación: Química Quàntica

Áreas temáticas: Química Química Chemistry

Acceso a la licencia de uso: https://creativecommons.org/licenses/by/3.0/es/

ISSN: 1434-1948

Identificador del autor: 0000-0001-8114-6658; ; ; ; ; ;

Fecha de alta del registro: 2018-02-28

Versión del articulo depositado: info:eu-repo/semantics/submittedVersion

Enlace a la fuente original: https://onlinelibrary.wiley.com/doi/abs/10.1002/ejic.201600514

Programa de financiación: plan; Excelencia; CTQ2014-58664-R

DOI del artículo: 10.1002/ejic.201600514

Entidad: Universitat Rovira i Virgili

Año de publicación de la revista: 2016

Tipo de publicación: Article Artículo Article