Catalytic Asymmetric α-Alkylation of Ketones with Unactivated Alkyl Halides.

A catalytic, enantioselective method for direct α-alkylation of ketones with unactivated alkyl halides is realized by employing an α-enolizable ketone in a nickel-catalyzed C(sp)-C(sp) cross-coupling reaction. The key to the success is attributed to a unique bimetallic ligand. A variety of acyclic ketones and unactivated alkyl iodides can serve as suitable substrates under mild conditions to generate chiral ketones with α-quaternary carbon stereocenters in high yields with good enantioselectivities.

Continuous programmable mid-infrared thermal emitter and camouflage based on the phase-change material InSbTe.

InSbTe (IST), a new non-volatile phase-change material (PCM), promises highly tunable infrared optical properties and offers a distinct path to the significant modulation of its optical scattering fingerprint, suggesting tremendous applications. In this Letter, we demonstrate and optimize a four-layer emitter based on IST, achieving an ultra-wide average emissivity variation of more than 94% in the middle-infrared region (MIR, 3-5 µm). This remarkable emissivity difference can be further continuously modified by changing the structural composition in terms of the amorphous and crystalline states of the IST layers.

Effect of Heat Treatment Temperature on the Spectral Properties of Cu-Ni Coating.

Cu-Ni coatings were prepared on the surface of nickel by electrodeposition method, and Cu-Ni coatings were heat-treated in 25-900 °C. Heat-treated Cu-Ni coatings were characterized with scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDAX) and X-ray diffraction (XRD) techniques, respectively. Effects of heat treatment temperature on the spectral properties of Cu-Ni coatings were studied.

Multiple interfaces in self-assembled breath figures.

This feature article describes the multiple interfaces in the breath figure (BF) method toward functional honeycomb films with ordered pores. If a drop of polymer solution in a volatile solvent such as carbon disulphide is placed in a humid environment, evaporative cooling leads to self-assembled arrays of condensed water droplets. After evaporation of the solvent and water, patterned pores can be formed.

Polystyrenes with hydrophilic end groups: synthesis, characterization, and effects on the self-assembly of breath figure arrays.

We report the synthesis and characterization of a series of hydroxyl-end-functionalized polystyrenes (PS-OH) and the formation of patterned porous films. The polymers were synthesized by chain end reaction of polystyrene having a bromide end group (PS-Br) with hydramines including ethanolamine, diethanol amine, 2-amino-1,3-propanediol, and 2-(2-aminoethoxy) ethanol. The polymers were characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), and differential scanning calorimetry (DSC).