Phase Control in the Synthesis of Magnetic Iron Sulfide Nanocrystals From a Cubane-Type Fe−S Cluster

Abstract

Phase control has been achieved in the synthesis of magnetic iron sulfide nanocrystals by the use of a single source precursor, a cubane type Fe-S cluster, bis(tetra-n-butylammonium) tetrakis[benezenethiolato-mu3-sulfido-iron]. This cluster cleanly decomposes in alkylamines to yield nanocrystals whose composition, structure, and dimensions are dependent on the temperature employed. At low temperatures, pyrrhotite type Fe7S8 nanocrystals with an average diameter of 5.6 nm are obtained. Higher temperatures yield griegite-Fe3S4 nanocrystals whose dimensions are tunable in the range 2.5-4.5 nm. All the obtained nanocrystals are superparamagnetic at room temperature.

Pyrite nanocrystals: shape-controlled synthesis and tunable optical properties via reversible self-assembly

“…24,25 For iron sulfide, the large number of crystal phases 20,26,27 has complicated the synthesis of phase-pure colloidal nanomaterials. So far, phase-pure iron disulfide nanocrystals, with only few exceptions, 23,[28][29][30] have been prepared with hydrothermal methods. 22,31,32 Shape-control, to the best of our knowledge, has only been reported in one occasion for a hydrothermal method based on different ligands and controlled concentrations of additives.…”

Magnetic greigite (Fe3S4) nanomaterials: Shape-controlled solvothermal synthesis and their calcination conversion into hematite (α-Fe2O3) nanomaterials

“…Fe 3 S 4 and FeS 2 nanoparticles were selectively prepared via the toluenethermal method [15]; Yu and co-workers reported the in situ magnetic-field-assisted hydrothermal route to prepare microrods of Fe 3 S 4 and FeS 2 [16]; O'Brien and Vanitha prepared magnetic iron sulfide nanocrystals including Fe 3 S 4 and Fe 7 S 8 from a cubanetype Fe-S cluster [17]. Furthermore, we have developed a simple hydrothermal method to controllably prepare Fe 3 S 4 samples using FeCl 3 ·6H 2 O or FeSO 4 ·7H 2 O and thioacetamide as raw materials, in which the reaction temperature plays the crucial role for preparing pure Fe 3 S 4 [18].…”

Shape-controlled synthesis of iron sulfide nanostructures via oriented attachment mechanism

“…In recent years, various methods have been proposed for the synthesis of iron sulfide nanostructures such as nanoparticles [14], nanowires [15], nanorods [16], nanosheets [17], nanoplates [18], and other complex morphologies [19] using vapor, solutionliquid-solid, vapor-liquid-solid [20,21], solvothermal [22,23], or template-directed [24] techniques. These methods generally use some form of the organic-phase synthesis technique to enhance the stability of the resulting nanostructure and to ensure a high monodispersity.…”

“…These methods generally use some form of the organic-phase synthesis technique to enhance the stability of the resulting nanostructure and to ensure a high monodispersity. For instance, in [14], monodisperse iron sulfide nanocrystals were prepared via the thermolysis of a sulfurcontaining single source precursor (SSP). SSPs containing preformed metal-sulfur bonds provide a convenient reactant for the growth of high-quality iron sulfide nanomaterials and are generally prepared in advance of the organic-phase synthesis process.…”