Effect of the framework flexibility on the centricities in centrosymmetric In2Zn(SeO3)4 and noncentrosymmetric Ga2Zn(TeO3)4

The solid-state syntheses, crystal structures, and characterization of two stoichiometrically similar quaternary mixed metal selenite and tellurite, In(2)Zn(SeO(3))(4) and Ga(2)Zn(TeO(3))(4), respectively, are reported. While In(2)Zn(SeO(3))(4) crystallizes in the centrosymmetric monoclinic space group P2(1)/n (No. 14) with a = 8.4331(7) ?, b = 4.7819(4) ?, c = 14.6583(13) ?, and β = 101.684(6)°, Ga(2)Zn(TeO(3))(4) crystallizes in the non-centrosymmetric space group I-43d (No. 220) with a = b = c = 10.5794(8) ?. In(2)Zn(SeO(3))(4) exhibits a two-dimensional crystal structure consisting of distorted InO(6) octahedra, ZnO(6) octahedra, and SeO(3) polyhedra. Ga(2)Zn(TeO(3))(4) shows a three-dimensional framework structure that is composed of GaO(4) or ZnO(4) and TeO(3) polyhedra. An effect of the framework flexibility on the space group centricity is discussed. The SHG (second harmonic generation) efficiency of noncentrosymmetric Ga(2)Zn(TeO(3))(4), using 1064 nm radiation, is similar to that of KH(2)PO(4) (KDP) and is not phase-matchable (Type 1). Complete characterizations including infrared spectroscopy and thermal analyses for the reported materials are also presented, as are dipole moment calculations.     

Enantio- and diastereoselective Michael addition reactions of α-cyanoketones to nitroalkenes catalyzed by binaphthyl-derived organocatalyst

The catalytic enantioselective and diastereoselective Michael addition reactions promoted by chiral bifunctional organocatalysts are described. The treatment of α-cyanoketones with nitroalkenes under mild reaction conditions afforded the corresponding γ-niro α-cyanoketones with excellent diastereoselectivities (up to syn/anti >99/1) and excellent enantioselectivities (up to 99% ee).     

The investigation of molecular affinity involved in poly(ethylene glycol)-based polymer-dispersed liquid crystal display

Acrylic polyethylene glycol(PEG)-based polymer-dispersed liquid crystal (PDLC) films have been fabricated to investigate the effect of intermolecular interactions on PDLC performance. For this purpose, the amphiphilic liquid crystal and polymers are selected as PDLC composite materials. The acrylic PEG contents are varied from 0 to 66.66 mol wt.% in order to understand the effects of different levels of additions on the microstructure and electro-optical properties of the PDLC films. For this intention, polarized optical microscopy and UV–vis spectroscopy are used. The extent of phase separation and anchoring energy are also examined using Fourier transform infrared (FTIR) spectroscopy and contact angle measurements in consequence of acrylic PEG addition. The contrast ratio, threshold voltage, as well as saturation voltage, tended to increase with the addition of acrylic PEG. The molecular affinity involved in the polymer matrix and LC molecules affected the phase separation which is responsible for the formation of domain size; this accordingly changed the electro-optical properties of PDLC film.     

Self-organized anisotropic wrinkling of molecularly aligned liquid crystalline polymer

Anisotropic wrinkling which utilizes the anisotropic nature of liquid crystalline polymer (LCP) is demonstrated as a means of physical self-assembly to produce periodic microstructures. Through the plasma treatment on the molecularly aligned LCP film surface, one-dimensionally ordered wrinkle pattern was spontaneously formed on glass substrates without employing external thin-film deposition or prestrain control of the system. Experimental results indicate that the directionality of the wrinkle pattern can be tailored by the structural ordering of LCP molecules in the bilayer system of a hard skin layer on a soft substrate. Studies on process variables, such as the plasma treatment time and the film thickness, were conducted to figure out the effect on the wrinkling morphology. Due to its spatial periodicity over a large area and undemanding requirement of the process, this approach can be a candidate for the microfabrication in various applications.     

ChemInform Abstract: Single-Crystal Structure of Partially Dehydrated Partially Mg2+-Exchanged Zeolite Y (FAU), [Mg30.5Na14(H2O)2.5] [Si117Al75O384]-FAU.

The crystal structure and the distribution and coordination geometry of Mg²⁺ ions in the title zeolite are determined by single crystal XRD.     

Mesoporous Nickel Oxide Nanowires: Hydrothermal Synthesis,Characterisation and Applications for Lithium‐Ion Batteries and Supercapacitors with Superior Performance

Mesoporous nickel oxide nanowires were synthesized by a hydrothermal reaction and subsequent annealing at 400 °C. The porous one‐dimensional nanostructures were analysed by field‐emission SEM, high‐resolution TEM and N₂ adsorption/desorption isotherm measurements. When applied as the anode material in lithium‐ion batteries, the as‐prepared mesoporous nickel oxide nanowires demonstrated outstanding electrochemical performance with high lithium storage capacity, satisfactory cyclability and an excellent rate capacity. They also exhibited a high specific capacitance of 348 F g^?1 as electrodes in supercapacitors.     

Colloidal Interactions of Inorganic Nanoparticles Grafted with Zwitterionic Polymer Brushes and Gels by Surface‐Mediated Seeded Polymerization

A robust and straightforward approach is introduced to synthesize inorganic nanoparticles chemically grafted with a zwitterionic poly(2‐methacryroyloxyethylphosphorylcholine) (PMPC) thin layers. The synthesis method is based on the surface‐mediated seeded polymerization. In order to observe how the polymer chain architectures affect colloidal interactions, the zinc oxide nanoparticles are grafted with linear brushes and with a thin hydrogel layer, respectively. The thickness of PMPC shell layers spans a few nanometers. The studies on suspension rheology for the nanoparticles show that the nanoparticles with PMPC brushes show the stronger repulsive force than those with the PMPC gel shell due to the entropic stabilization. When the shear force is applied to the Pickering emulsion produced by assembly of the nanoparticles, it is noticeable that the presence of PMPC brushes on the particles rather enhances the drop‐to‐drop attraction, which presumably stems from the entanglement of polymer chains between the contacted interfacial planes of the emulsion droplets during shearing.

     

Influence of emulsion types on nucleation kinetics and growth habit in the cooling crystallization

Experiments on unseeded batch cooling crystallization were made to investigate the influence of emulsion [solution in non‐solvent (S/NS) emulsion and non‐solvent in solution (NS/S) emulsion] on crystal size and growth habit of various materials such as hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine, ammonium sulfate, potassium dihydrogen phosphate (KDP), and γ‐glycine. Size of crystals obtained from the S/NS emulsions was found to be significantly larger than that obtained from the NS/S emulsions. Those results were explained by broad induction time distribution of nucleation in the isolated solution droplets and subsequent seeding effect by free movement of early‐induced crystals by vigorous agitation. As a result, the population density of crystals was shown to be smaller in the S/NS emulsions than that in the NS/S emulsions. In the S/NS emulsions, desupersaturation rate should be slow and high supersaturation is subsequently generated during crystal growth stage. Therefore, it may be concluded that crystal morphology of the materials with supersaturation dependent growth habit, such as ammonium sulfate, KDP and γ‐glycine, can be controlled by selection of emulsion type.     

Thermally Cross‐Linkable Hole Transport Polymers for Solution‐Based Organic Light‐Emitting Diodes

Two thermally cross‐linkable hole transport polymers that contain phenoxazine and triphenylamine moieties, X‐P1 and X‐P2, are developed for use in solution‐processed multi‐stack organic light‐emitting diodes (OLEDs). Both X‐P1 and X‐P2 exhibit satisfactory cross‐linking and optoelectronic properties. The highest occupied molecular orbital (HOMO) levels of X‐P1 and X‐P2 are −5.24 and −5.16 eV, respectively. Solution‐processed super yellow polymer devices (ITO/X‐P1 or X‐P2/PDY‐132/LiF/Al) with X‐P1 or X‐P2 hole transport layers of various thicknesses are fabricated with the aim of optimizing the device characteristics. The fabricated multi‐stack yellow devices containing the newly synthesized hole transport polymers exhibit satisfactory currents and power efficiencies. The optimized X‐P2 device exhibits a device efficiency that is dramatically improved by more than 66% over that of a reference device without an HTL.