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RESEARCH PRODUCT

Magnetostructural correlations in CuII−NC−WV linkage: the case of [CuII(diimine)]2+−[WV(CN)8]3− 0D assemblies

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International audience; We report on the syntheses, crystal structures, and magnetic properties of two cyano-bridged molecular assemblies: [CuII(phen)3]2{[CuII(phen)2]2[WV(CN)8]2}(ClO4)2·10H2O (phen = 1,10-phenanthroline) (1) and {[CuII(bpy)2]2[WV(CN)8]} {[CuII(bpy)2][WV(CN)8]}·4H2O (bpy = 2,2′-bipyridyl) (2). Compound 1 consists of cyano-bridged [CuII2WV2]2− molecular rectangles and isolated [CuII(phen)3]2+ complexes. The molecular structure of 2 reveals cyano-bridged trinuclear [CuII2WV]+ and dinuclear [CuIIWV]− ions. Magnetic interactions in 1 are interpreted in terms of the model of a tetranuclear moiety consisting of two ferromagnetic CuII−NC−WV units (J1 = +39(4) cm−1) interacting antiferromagnetically (J2 = −1.6(4) cm−1). The analysis of the magnetic response of 2 reveals ferromagnetic interaction within the [CuII−NC−WV−CN−CuII]+ and [CuII−NC−WV]− isolated units, characterized by J = +35(7) cm−1 and antiferromagnetic coupling between them (4J′ = −0.30(8) cm−1). The discussion of the magnetic behavior and the correlation of the JCuW parameters with the geometry of cyano bridges at copper(II) centers of 1 and 2 is based on the DFT calculations, which yield Jav = +13.2 cm−1 for 1 and J = +31 cm−1 for 2. The domination of the ferromagnetic CuII−NC−WV interaction in 1 and 2 originates from the mutual orthogonality of natural magnetic orbitals in the case of coordination of cyano bridges at the equatorial sites of Cu(II) moieties.