Here, the surface functionalization of CdSe and CdSe/CdS core/shell nanocrystals (NCs) with compact chloride and indium-chloride-complex ligands is reported. The ligands provide not only short interparticle distances but additionally control doping and passivation of surface trap states, leading to enhanced electronic coupling in NC-based arrays. The solids based on these NCs show an excellent electronic transport behavior after heat treatment at the relatively low temperature of 190 degrees C. Indeed, the indium-chlorido-capped 4.5 nm CdSe NC based thin-film field-effect transistor reaches a saturation mobility of = 4.1 cm(2) (V s)(-1) accompanied by a low hysteresis, while retaining the typical features of strongly quantum confined semiconductor NCs. The capping with chloride ions preserves the high photoluminescence quantum yield (approximate to 66%) of CdSe/CdS core/shell NCs even when the CdS shell is relatively thin (six monolayers). The simplicity of the chemical incorporation of chlorine and indium species via solution ligand exchange, the efficient electronic passivation of the NC surface, as well as their high stability as dispersions make these materials especially attractive for wide-area solution-processable fabrication of NC-based devices

Polycrystalline Cu3-xP was successfully synthesized in different ionic liquids comprising imidazolium and phosphonium cations. The reaction of elemental copper and red phosphorus in trihexyltetradecylphosphonium chloride at 200 °C led to single-phase Cu3-xP (x = 0.05) within 24 h with a quantitative yield (99%). Liquid-state nuclear magnetic resonance spectroscopy of the ionic liquids revealed degeneration of the imidazolium cations under the synthesis conditions, while phosphonium cations remain stable. The solid products were characterized with X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, solid-state nuclear magnetic resonance spectroscopy, and elemental analysis. A reinvestigation of the electronic transport properties of Cu2.95(4)P showed metallic behavior for the bulk material. The formation of CuP2 during the synthesis of phosphorus-rich Cu3-xP (x ≥ 0.1) was observed.

After suspensions of micellar casein or nonmicellar sodium caseinate had been heated, respectively, in the presence and absence of glucose for 0-4 h at 100 °C, glycation compounds were quantitated. The formation of Amadori products as indicators for the "early" Maillard reaction were in the same range for both micellar and nonmicellar caseins, indicating that reactive amino acid side chains within the micelles are accessible for glucose in a comparable way as in nonmicellar casein. Significant differences, however, were observed concerning the formation of the advanced glycation end products (AGEs), namely, N(ε)-carboxymethyllysine (CML), pyrraline, pentosidine, and glyoxal-lysine dimer (GOLD). CML could be observerd in higher amounts in nonmicellar casein, whereas in the micelles the pyrraline formation was increased. Pentosidine and GOLD were formed in comparable amounts. Furthermore, the extent of protein cross-linking was significantly higher in the glycated casein micelles than in the nonmicellar casein samples. Dynamic light scattering and scanning electron microscopy showed that glycation has no influence on the size of the casein micelles, indicating that cross-linking occurs only in the interior of the micelles, but altered the surface morphology. Studies on glycation and nonenzymatic cross-linking can contribute to the understanding of the structure of casein micelles.

Keywords: In situ spectroscopy / Ionic liquids / Nanoparticles / NMR spectroscopy / PhosphorusRed phosphorus is far less reactive than the white allotrope. On the other hand, it is easier to handle and not as toxic as white phosphorus. In the Lewis-acidic ionic liquid (IL) [BMIm]Cl·2AlCl 3 ([BMIm] = 1-butyl-3-methylimidazolium), red phosphorus and elemental iodine form several iodides at moderate temperature. 31 P liquid-and solid-state NMR spectroscopy was used to rationalize the reaction at various tem- [a]3991 peratures and ratios of the starting materials. Monitoring of the reaction revealed nanoscale red-phosphorus particles. In addition to this top-down formation, phosphorus nanoparticles were also obtained in a bottom-up synthesis by dissociation of P 2 I 4 in the IL. Depending on the ratio of red phosphorus and iodine, as well as the reaction temperature, P 2 I 4 , PI 3 , or P 2 I 5 + dominate.

Much effort has been put into the characterization of the final superstructures and the investigation of the NP assembly by many groups. We know from these studies that the particles can arrange into fcc, bcc, or hcp superlattices showing a long-range ordering of the primary building units. [8] These supracrystals show a high symmetry and well-defined facets yielding octahedra, [7] hexagonal plates, [6] five-armed stars, [9] and more complex twinned structures. [10] Furthermore, there are a lot of investigations dealing with the self-assembly of nanoparticles and the corresponding mechanism. Different models have been developed ranging from a hard sphere model, [11,12] where the NPs are assumed to be spherical objects of similar size, to soft sphere models, where the kind of ligand determines the self-assembly. [13,14] Also the driving force and the assembly probability on steps, holes, or edges have been calculated. [15] Nevertheless, the formation process itself, which takes place in solution, has yet to be fully understood.In this study, we achieved insight into the formation process in solution by investigating the morphology of the resulting supracrystals. Due to the large variety of reported morphologies, we decided to examine one of the most frequently observed symmetrical crystal shapes, which will be called trigonal supracrystal (see Figure 1) in the following. Additionally, we surveyed the influences of different preparation parameters on the resulting superstructures.Trigonal Ag supracrystals have been prepared via gas-phase destabilization techniques (details can be found in the Supporting Information). On the basis of high-resolution scanning electron microscopy (HRSEM), small angle X-ray scattering (SAXS), and transmission electron microscopy (TEM) measurements, the concept of substrate-affected growth is introduced to explain the formation of trigonal shaped supracrystals yielding the size of the supracrystals, which are formed in solution. We will show that the self-assembly can be influenced by the preparation parameters such as concentration, temperature, NP size, and size distribution leading to a control of the size of the supracrystals formed in solution. In order to evaluate the concept of substrate-affected growth, the investigations have been extended toward Au.From the literature, we can conclude that trigonal supracrystals occurred, if there is on the one hand a fcc arrangement of the NPs and on the other hand a plane (substrate) surface. The Formation and Morphology of Nanoparticle SupracrystalsDanny Haubold, Annett Reichhelm, Alexander Weiz, Lars Borchardt, Christoph Ziegler, Lydia Bahrig, Stefan Kaskel, Michael Ruck, and Alexander Eychmüller* Supracrystals are highly symmetrical ordered superstructures built up from nanoparticles (NPs) via self-assembly. While the NP assembly has been intensively investigated, the formation mechanism is still not understood. To shed some light onto the formation mechanism, one of the most common supracrystal morphologies, the trigonal structures, ...