Using Prussian blue analogue nanoparticles confined into ordered mesoporous silica monoliths as precursors of oxides

International audiencePowdered Prussian blue analogues (PBAs) and PBAs confined in ordered mesoporous silica monoliths were used as oxide precursors through thermal treatment under an oxidizing atmosphere. The study focuses on the transformation of the alkali cation-free CoCo PBA of chemical formula K0.1CoII4[CoIII(CN)6]2.7·20 H2O. The compounds were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), IR spectroscopy and small-angle X-ray scattering (SAXS), and the magnetic properties of the calcined samples were investigated. In both cases, powdered and confined PBAs, the coordination polymers are transformed into well-crystallized Co3O4 spinel oxide. In the case of the confined PBA, isolated Co3O4 single crystals confined within the ordered mesoporosity of the monoliths were evidenced by HRTEM. A preliminary study shows an effect of particle size and confinement on the magnetic properties of the confined oxide particles

Salts and Solvents Effect on the Crystal Structure of Imidazolium Dicarboxylate Salt Based Coordination Networks

International audienceThe solvothermal synthesis of novel metal–organic networks from the 1,3-bis(carboxymethyl)-imidazolium chloride ([H2L][Cl]) and cobalt or nickel salts (acetate or nitrate) in different solvents (water or ethanol and water/ethanol or water/ethylene glycol mixture) has been explored leading to four isotypic compounds of general formula [M(L)(H2O)4][Cl]·Solv with M = Ni or Co and Solv = H2O for 1 and 2, respectively, and M = Ni or Co and Solv = (EG)0.5 for 3 and 4, respectively, and two other isostructural compounds, namely, [Ni(L)(ox)0.5(μ2-H2O)0.5] (5) and [Co(L)(ox)0.5(μ2-H2O)0.5] (6) where the in situ formation of oxalate (ox) was observed. The structural characterizations evidence a significant influence of the solvent as well as of the metal salt on the structure and crystallinity of the final compounds, the former leading to observation of different magnetic behaviors. A one-dimensional antiferromagnetic behavior is thus observed in compounds 5 and 6 containing oxalate ligand while compounds 1–4 exhibited typical behavior of quasi-isolated magnetic species

Octahedral Hexachloro Environment of Dy3+ with Slow Magnetic Relaxation and Luminescent Properties

International audienceThe compound [BiCNIm]3[DyCl6] was synthesized from a nitrile-functionalized imidazolium ionic liquid [BiCNIm][Cl] and DyCl3 ⋅ 6H2O in acetonitrile using solvothermal conditions. Structural characterization reveals that the Dy3+ ions are in a quasi-regular octahedral environment, formed by six chloride anions. The magnetic study indicates that this mononuclear compound exhibits a Single Ion Magnet behaviour. This behaviour is compared to that of other mononuclear compounds containing Dy3+ ions in various octahedral environment

Noncentrosymmetric Cu(II) Layered Hydroxide: Synthesis, Crystal Structure, Nonlinear Optical, and Magnetic Properties of Cu 2 (OH) 3 (C 12 H 25 SO 4 )

International audienceSingle-crystals of the layered copper hydroxide dodecylsulfate Cu2(OH)3(C12H25SO4) have been obtained for the first time, by controlled hydrolysis of an aqueous copper acetate solution. Interestingly this compound crystallizes in a non-centrosymmetric space group (P21, a = 5.591(10) Å, b = 6.108(11) Å, c = 26.96(5) Å, = = 90°, = 92.76°), which is further confirmed by non-linear optical measurements. Within the course of the synthesis, a probable intermediat

Noncentrosymmetric Cu(II) Layered Hydroxide: Synthesis, Crystal Structure, Nonlinear Optical, and Magnetic Properties of Cu 2 (OH) 3 (C 12 H 25 SO 4 )

International audienceSingle-crystals of the layered copper hydroxide dodecylsulfate Cu2(OH)3(C12H25SO4) have been obtained for the first time, by controlled hydrolysis of an aqueous copper acetate solution. Interestingly this compound crystallizes in a non-centrosymmetric space group (P21, a = 5.591(10) Å, b = 6.108(11) Å, c = 26.96(5) Å, = = 90°, = 92.76°), which is further confirmed by non-linear optical measurements. Within the course of the synthesis, a probable intermediat