Quantum dots metallic precursors using

A number of zinc selenium complexes have now been characterized, with particular interest in the formation of zinc selenide semiconductors and quantum dots. In many cases analogous structures to those observed with thiol or thiolates are recorded. 77Se NMR is frequently used in characterization, and comparison with the sulfur equivalent is relevant. Zinc selenium compounds are of particular interest as precursors for metal/selenide materials and their relevance as models for selenocysteine-containing metalloproteins. 

To improve control over nanoparticle formation while using wet impregnation, several authors used consecutive impregnations (four to five times) with drying the material in between to insure that mesopores are completely filled with metal precursor [31,32]. In this case, the amount of precursor is fixed and determined by the pore size and volume the recipe is well reproducible as the final particle size is controlled by the precursor amount and in some cases by the pore size. This avenue led to a 3D quantum dot lattice inside the mesoporous silica film due to regular CdS particle formation, when impregnation was followed by precipitation with H2S and the procedure was repeated until the film satura-... 

Non-aqueous synthetic methods have recently been used to assemble mesoporous transition metal oxides and sulfides. This approach may afford greater control over the condensation-polymerization chemistry of precursor species and lead to enhanced surface area materials and well ordered structures [38, 39], For the first time, a rational synthesis of mesostructured metal germanium sulfides from the co-assembly of adamantanoid [Ge4S ()]4 cluster precursors was reported [38], Formamide was used as a solvent to co-assemble surfactant and adamantanoid clusters, while M2+/1+ transition metal ions were used to link the clusters (see Fig. 2.2). This produced exceptionally well-ordered mesostructured metal germanium sulfide materials, which could find application in detoxification of heavy metals, sensing of sulfurous vapors and the formation of semiconductor quantum anti-dot devices. 

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