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Polymer blends are broadly important in chemical science and chemical engineering and have led to a wide range of commercial products, however their precise structure and phase morphology is often not well understood. Here we show for the first time that π-conjugated polytellurophenes and high-density polyethylene form blends that can serve as active layers in field-effect transistor devices and can be characterized by a variety of element-specific imaging techniques such as STEM and EDX. Changing the hydrocarbon content and degree of branching on the polytellurophene side-chain leads to a variety of blend structures, and these variations can be readily visualized. Characterization by electron microscopy is complemented by topographic and X-ray methods to establish a nano- to micro-scale picture of these systems. We find that blends that possess microscale networks function best as electronic devices; however, contrary to previous notions a strong correlation between nanofiber formation and electrical performance is not observed. Our work demonstrates that use of organometallic polymers assists in clarifying relevant structure–property–function relationships in multicomponent systems such as semiconductor:insulator blends and sheds light on the structure development in polymer:polymer blends including crystallization, phase separation, and formation of supramolecular arrangements. [ABSTRACT FROM AUTHOR]

A photoactive manganese carbonyl complex namely, fac-[Mn(pqa)(CO)3]ClO4 (abbreviated as {Mn-CO}, pqa = (2-pyridylmethyl)(2-quinolylmethyl)amine) has been incorporated in the pores of 60 nm mesoporous Al-MCM-41 nanoparticles. Strong electrostatic interactions with the negatively charged walls of the aluminosilicate host entrap the cationic carbonyl complex in the resulting material {Mn-CO} @Al-MCM-41 which has been characterized by various physical techniques and chemical analysis. The sample morphology and microstructure of the material have been established by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results of powder X-ray diffraction (PXRD) data and the SEM-EDX elemental maps of Si, O, Al and Mn confirm that the carbonyl complex is within the pores of the nanoparticles. The 2% manganese content of {Mn-CO}@Al-MCM-41, determined by acid digestion followed by inductively coupled plasma-optical emission spectroscopy (ICP-OES), indicates efficient loading of the carbonyl complex in the nanoparticles. In biological buffer solutions, less than 2% leaching of {Mn-CO} from the nanoparticles was noted within a period of 24 h. When exposed to a broadband visible light source (A > 350 nm), {Mn-CO}@Al-MCM-41 rapidly releases CO, as confirmed by the reduced myoglobin assay. The utility of light-induced CO delivery by {Mn-CO}(aAl-MCM-41 has been established by its capacity to relax rat aorta muscle rings in tissue bath experiments. [ABSTRACT FROM AUTHOR]

A photoactive manganese carbonyl complex namely, fac-[Mn(pqa)(CO)[sub 3]]ClO[sub 4] (abbreviated as {Mn-CO}, pqa = (2-pyridylmethyl)(2-quinolylmethyl)amine) has been incorporated in the pores of 60 nm mesoporous Al-MCM-41 nanoparticles. Strong electrostatic interactions with the negatively charged walls of the aluminosilicate host entrap the cationic carbonyl complex in the resulting material {Mn-CO} @Al-MCM-41 which has been characterized by various physical techniques and chemical analysis. The sample morphology and microstructure of the material have been established by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results of powder X-ray diffraction (PXRD) data and the SEM-EDX elemental maps of Si, O, Al and Mn confirm that the carbonyl complex is within the pores of the nanoparticles. The 2% manganese content of {Mn-CO}@Al-MCM-41, determined by acid digestion followed by inductively coupled plasma-optical emission spectroscopy (ICP-OES), indicates efficient loading of the carbonyl complex in the nanoparticles. In biological buffer solutions, less than 2% leaching of {Mn-CO} from the nanoparticles was noted within a period of 24 h. When exposed to a broadband visible light source (λ > 350 nm), {Mn-CO}@Al-MCM-41 rapidly releases CO, as confirmed by the reduced myoglobin assay. The utility of light-induced CO delivery by {Mn-CO}@Al-MCM-41 has been established by its capacity to relax rat aorta muscle rings in tissue bath experiments. [ABSTRACT FROM AUTHOR]

Using our transfer hydrogenation (TH) pre-catalyst trans-(R,R)-[Fe(NCMe)CO(PPhCHCH=NCHPh-)][BF] ( 1) we investigated the reverse reaction, oxidative kinetic resolution, and were able to achieve turn-over frequencies up to 335 h and s-values in favour of the (R)-alcohol up to 10.2. Using racemic 1-phenylethanol we optimized reaction conditions to maximize enantioselectivity and turn-over frequency (TOF) and studied the effect of different proton/hydride acceptors, temperatures, and bases. Using KOtBu as the base and benzophenone in THF as the solvent and acceptor at 45 °C, we tested a series of substrates with varying electronic and steric factors. By increasing the steric bulk at the alcohol, the enantioselectivity increased, however the TOF decreased dramatically. Varying the electronics of the substrates using electron withdrawing and donating substituents showed a less significant effect. We propose that the active species in catalysis is zero-valent iron nanoparticles (Fe NPs), a postulate that we support with microscopy imaging, sub-stoichiometric poisoning experiments, and analysis of the reaction profile. Further support is given in terms of a polymer-supported substrate experiment whereby the active species in catalysis is too large to permeate the pores of a functionalized polymer. To the best of our knowledge, we propose that this is the first reported example of using a nanoparticle surface for oxidative kinetic resolution. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

We report on the synthesis of optically transparent, mesoporous, monolithic diamond from periodic mesoporous carbon CMK-8 at a pressure of 21 GPa. The phase transformation is already complete at a mild synthesis temperature of 1,3000C without the need of a catalyst. Surprisingly, the diamond is obtained as a mesoporous material despite the extreme pressure. X-ray diffraction, SEM, transmission electron microscopy, selected area electron diffraction, high-resolution transmission electron microscopy, and Z-contrast experiments suggest that the mesoporous diamond is composed of interconnected diamond nanocrystals having diameters around 5-10 nm. The Brunauer Emmett Teller surface area was determined to be 33 m2 g' according Kr sorption data. The mesostructure is diminished yet still detectable when the diamond is produced from CMK-8 at 1,600 O( and 21 GPa. The temperature dependence of the porosity indicates that the mesoporous diamond exists metastable and withstands transformation into a dense form at a significant rate due to its high kinetic inertness at the mild synthesis temperature. The findings point toward ultrahard porous materials with potential as mechanically highly stable membranes. [ABSTRACT FROM AUTHOR]

The tyrosine kinase receptor Tie2 is expressed on endothelial cells, and together with its ligand angiopoietin-1 (Ang1), is important for angiogenesis and vascular stability. Upon activation by Ang1, Tie2 is rapidly internalized and degraded, a mechanism most likely necessary to attenuate receptor activity. Using immunogold electron microscopy, we show that on the surface of endothelial cells, Tie2 is arranged in variably sized clusters containing dimers and higher order oligomers. Clusters of Tie2 were expressed on the apical and basolateral plasma membranes, and on the tips of microvilli. Upon activation by Ang1, Tie2 co-localized with the clathrin heavy chain at the apical and basolateral plasma membranes and within endothelial cells indicating that Tie2 internalizes through clathrin-coated pits. Inhibiting cellular endocytosis by depleting cellular potassium or by acidifying the cytosol blocked the internalization of Tie2 in response to Ang1. Our results suggest that one pathway mediating the internalization of Tie2 in response to Ang1 is through clathrin-coated pits. [ABSTRACT FROM AUTHOR]

Reports the rational synthesis of a family of metal germanium sulphide mesostructured materials prepared by a non-aqueous surfactant-templated assembly of adamantanoid [Ge4S10]4- cluster precursers. Self-organization of anions in formamide solution with metal cations to create well ordered hexagonal metal germanium sulphide mesostructures; Significance of discoveries in applications as diverse as detoxification of heavy metals in polluted water streams.

Discusses the morphogenesis of shapes and surface patterns in mesoporous silica. The use of scanning electron microscopy to catalogue the basic topologies and surface patterns, and transmission electron microscopy; The proposition that the morphogenesis of shapes and surface patterns can be rationalized in terms of growth of a silicate liquid-crystal embryo 15,16 with a hexagonal cross-section that under different initial reaction conditions, is subject to increasing degrees of curvature.

Describes a surfactant-templated synthesis of oriented mesoporous silica films grown at the mica-water interface. Methodology of the synthesis of the surfactant assembly; Demonstration that such films can be grown without a solid substrate; Potential applications in catalysis, separation technology and biomedicine.

Gold-plated silver nanoparticles (Au@AgNPs, shell@core) with high stability in various environments detrimental to AgNPs have been produced with preserved plasmonic and sensing properties. [ABSTRACT FROM AUTHOR]