Incommensurate nature of the multilayered molecular ferromagnetic metals based on bis(ethylenedithio)tetrathiafulvalene and bimetallic oxalate complexes.

The salt [ET]x[MnRh(ox)(3)].CH(2)Cl(2) (x = 2.526(1)) has been obtained and characterized. This paramagnetic metal is essentially isostructural to the ferromagnetic metal [ET]y[MnCr(ox)(3)].CH(2)Cl(2) (y approximately equal to 3) and provides a definite answer on the origin of the structural disorder present on such systems. As in the ferromagnetic analogue, this material shows high electrical conductivity at room temperature (13 S.cm(-1)) and metallic behavior.

Design of molecular materials combining magnetic, electrical and optical properties †

The possibilities offered by hybrid functional materials formed by two molecular networks in the context of crystal engineering are illustrated with two different examples: (i) hybrid magnets constructed from combination of an extended ferromagnetic or ferrimagnetic inorganic network, with a molecular paramagnetic metal complex acting as template. (ii) Hybrid organic–inorganic compounds combining an organic π-electron donor network that furnishes the pathway for electronic conductivity, with inorganic metal complexes that act as structural and/or magnetic components. These examples illustrate how this hybrid approach allows the design of molecular materials combining non-conventional magnet…

Polyoxometalates: From Magnetic Models to Multifunctional Materials

In this article we have presented some recent achievements of the polyoxometalates in the fields of molecular magnetism and functional molecular materials. In the context of the molecular magnetism we have shown that POMs provide ideal examples of magnetic clusters with coexisting ferro and antiferromagnetic exchange interactions which can be investigated using a variety of magnetic techniques, including the Inelastic Neutron Scattering spectroscopy, to get a thorough characterization of the magnetic levels in these large clusters, and to test the validity of the spin hamiltonians commonly used in magnetism.

Organic/inorganic molecular conductors based upon perylene and Lindquist-type polyoxometalates

The preparation, structures and physical properties of the organic/inorganic radical salts based upon perylene (per) and Lindquist type polyoxometalates (POMs) are reported. Three new hybrid salts have been prepared: (per)5[Mo6O19] (1), (per)5[W6O19] (2), and (per)5[VW5O19] (3). Only structures 1 (P, Z = 2) and 3 (P, Z = 2) were fully determined as compound 2 was found to have unit cell parameters practically identical to 1 and, therefore, is considered isostructural with the latter. The structures consist of interpenetrated organic and mixed organic/inorganic layers in the ac plane alternating along the a direction. The organic layers present a novel packing mode of the perylene molecules …

Hybrid materials containing organometallic cations and 3-D anionic metal dicyanamide networks of type [Cp*2M][M′(dca)3]

A new series of hybrid materials of type [Cp*2M][M′(dca)3] has been prepared by cation templation and structurally characterised (M = Fe(III), Co(III); M′ = Mn(II), Fe(II), Co(II), Ni(II), Cd(II); dca− = N(CN)2−). The crystallographic analysis of [Cp*2Fe][Cd(dca)3] showed that the [Cd(dca)3]− anionic framework is of a symmetrical 3-D α-polonium type, containing octahedral Cd nodes and μ1,5-dca bridging ligands. The [Cp*2Fe]+ cations occupy the cube-like cavities within the framework. The cationic and anionic-framework sublattices remain magnetically independent and display susceptibilities, over the range 300 to 2 K, of a Curie–Weiss nature obtained by adding a S = 1/2 (Cp*2Fe+) or a S = 0 …

New conducting radical salts based upon Keggin-type polyoxometalates and perylene

Three new radical salts, Per6[PMo12O40]·CH2Cl2 (1), Per6[PMo12O40]·CH3CN (2), and Per9(NBu4)4[SiW12O40]2 (3) (Per = perylene), have been synthesised and their electrical and magnetic properties characterised. These three salts are diamagnetic and they behave as semiconductors with room temperature conductivities of 69, 3.6 and 0.85 S cm−1. While salt 2 presents hole-type conduction and 3 exhibits electron-dominated electrical transport properties, salt 1 shows at 150 K an abrupt change in the thermal dependence of the electrical conductivity and the Seebeck coefficient suggesting a phase transition.

Oxalate‐Based 3D Chiral Magnets: The Series [Z II (bpy) 3 ][ClO 4 ][M II Fe III (ox) 3 ] (Z II = Fe, Ru; M II = Mn, Fe; bpy = 2,2'‐Bipyridine; ox = Oxalate Dianion)

The synthesis, structure, and physical properties of the oxalate-based molecular magnets with the formula [ZII(bpy)3][ClO4][MIIFeIII(ox)3] (ZII = Fe, Ru; MII = Mn, Fe; bpy = 2,2'-bipyridine; ox = oxalate dianion) are presented here. All compounds are isostructural and crystallize in the chiral cubic space group P4132, and contain three-dimensional dimetallic networks formed by alternating MII and MIII ions that are connected by oxalate anions. These compounds exhibit strong antiferromagnetic interactions that give rise to magnetic ordering as ferrimagnets or weak ferromagnets, with critical temperatures of up to 20 K, which is twice as high as those found for the isostructural magnets based…

Multifunctional molecular materials

Magnetic properties of hybrid molecular materials based on oxalato complexes

Abstract The use of [MIII(ox)3]3− (MIII=Ru, Rh) complexes as building blocks for hybrid molecular materials is highlighted with two different synthetic approaches. The first strategy is the combination of organic donors and [RuIII(ox)3]3− units, resulting in the radical salt of formula TTF3[Ru(ox)3]·0.5EtOH·4H2O (1) which shows coexistence of paramagnetism and semiconducting properties. The second approach is the synthesis of extended 2D bimetallic oxalato-bridged networks of general formula [FeCp2 *][MIIRh(ox)3] in which paramagnetic layers of decamethylferricinium cations are alternated with paramagnetic bimetallic layers.

Layered Molecule-Based Magnets Formed by Decamethylmetallocenium Cations and Two-Dimensional Bimetallic Complexes [MIIRuIII(ox)3]−(MII=;Mn, Fe, Co, Cu and Zn; ox=oxalate)

Abstract A new series of hybrid organometallic-inorganic layered magnets with formula [Z III Cp * 2 ] [M II Ru III (ox) 3 ] ( Z III =Co and Fe; M II =Mn, Fe, Co, Cu, and Zn; ox=oxalate: Cp * =pentamethylcyclopentadienyl) has been prepared. All of these compounds are isostructural to the previously reported [ Z III Cp * 2 ] [ M II M III (ox) 3 ] ( M III =Cr, Fe) series and crystallize in the monoclinic space group C 2/ m , as found by powder X-ray diffraction analysis. They are novel examples of magnetic materials formed by bimetallic oxalate-based extended layers separated by layers of organometallic cations. The magnetic properties of all these compounds have been investigated (ac and dc m…

Metallic Conductivity in a Polyoxovanadate Radical Salt of Bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF): Synthesis, Structure, and Physical Characterization ofβ″-(BEDT-TTF)5[H3V10O28]·4H2O

CCDC 1484963: Experimental Crystal Structure Determination

Related Article: Eugenio Coronado , José R. Galán-Mascarós , Carlos J. Gómez-García , Eugenia Martínez-Ferrero , Sander van Smaalen|2004|Inorg.Chem.|43|4808|doi:10.1021/ic049424a

CCDC 1484964: Experimental Crystal Structure Determination

Related Article: Eugenio Coronado , José R. Galán-Mascarós , Carlos J. Gómez-García , Eugenia Martínez-Ferrero , Sander van Smaalen|2004|Inorg.Chem.|43|4808|doi:10.1021/ic049424a