Molecule-Based Magnetic Nanoparticles:  Synthesis of Cobalt Hexacyanoferrate, Cobalt Pentacyanonitrosylferrate, and Chromium Hexacyanochromate Coordination Polymers in Water-in-Oil Microemulsions

Abstract

Although considerable effort has been dedicated to the controlled synthesis of nanoparticles with classical inorganic structures, there are few reports on the formation of nanoscale materials based on supramolecular compounds such as transition metal coordination polymers. Here we describe the synthesis of crystalline nanoparticles of three different molecule-based magnetic materials, cobalt hexacyanoferrate, cobalt pentacyanonitrosylferrate, and chromium hexacyanochromate, by coprecipitation reactions involving mixtures of water-in-oil microemulsions. The cobalt-containing nanoparticles are regular in shape and size and have dimensions between 12 and 22 nm depending on the concentration of the reactants trapped within the water droplets. At sufficiently high particle concentrations, superlattice structures are formed by solvent evaporation. Growth of the nanoparticles occurs by interdroplet aggregation of primary clusters that are nucleated in the confined spaces of the microemulsion reaction field.

Regulations of silver halide nanostructure and composites on photocatalysis

“…Generally, microemulsions composited with various micelles and reverse micelles are the most common soft templates in nanoparticles synthesis of inorganic crystals, noble metals and metal oxides [116,[178][179][180][181][182][183][184][185]. The professional term of Bmicroemulsion^was proposed by J. H. Schulman, who introduced the Bmicro emulsion^systems describing a stable transition between oil-rich and water-rich mixture [186,187].…”

Magnetization Reversal in CsNiIICrIII(CN)6 Coordination Nanoparticles: Unravelling Surface Anisotropy and Dipolar Interaction Effects

“…[ 1 ] In the past 10 years, the synthesis and the magnetic behaviour of coordination nanoparticles based on cyanidebridged networks has been the subject of intense research effort because of their versatile physical properties and particularly because of their magnetic, optical and thermal bistability. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Among those networks are the bimetallic cyanide-bridged Prussian blue analogues (PBA) with face centred cubic structure ( Fm3m ) and general formula A x M y [M′(CN) 6 ] z , where M and M′ are divalent and trivalent metallic ions respectively and A is an alkaline ion. [19][20][21][22][23][24] The fi rst reports on PBA coordination nanoparticles using a bottom-up approach started in 1997 using different chemical processes that required the presence of an agent (organic or inorganic) to stabilize the particles, and thus precluded www.afm-journal.de www.MaterialsViews.com wileyonlinelibrary.combulk of the particles and thus induce relatively large local anisotropy on the surface.…”

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] We have reported an alternative surfactant-free synthesis that led, by adjusting the physico-chemical para meters, to the formation of stable colloidal aqueous solutions of nanocrystals with a narrow size distribution. [ 25,26 ] This stability originates from the negatively charged surface and has been exploited to set a versatile simple synthetic route for core-multishell heterostructured nanoparticles.…”

Synthesis and characterization of cobalt nitroprusside nano particles: Application to sulfite sensing in food and water samples

“…Metal nanoparticles as catalysts have been vigorously investigated because of their specific properties such as large surface area and their superior properties which are different from their bulk counterparts [15]. Inorganic nanoparticles are very useful candidates for electrochemical studies owing to their outstanding activity and catalytic power [16][17][18]. The large surface-to-volume ratio and the active sites of these nano-sized metal particles in electrocatalysis constitute a part of the driving force in developing the nanosized electrocatalysts.…”