High‐performance fluorine‐containing BDT‐based copolymer for organic solar cells with a high open circuit voltage

A new donor–acceptor (D‐A) conjugated copolymer (PBDTT(ff)‐ttTPD) based on fluorine‐substituted benzodithiophene (BDT) and 6‐alkylthienothienyl thieno[3,4‐c]pyrrole‐4,6‐dione (ttTPD) has been synthesized via a Stille cross‐coupling reaction. As a control, the nonfluorinated BDT‐based ttTPD copolymer (PBDTT‐ttTPD) was also synthesized by using the same polymerization method. The number‐average molecular weights (M _n) of PBDTT(ff)‐ttTPD and PBDTT‐ttTPD were found to be 48,000 g/mol (? = 2.2) and 43,000 g/mol (? = 2.1), respectively. The HOMO levels of PBDTT(ff)‐ttTPD and PBDTT‐ttTPD were calculated to be ?5.65 and ?5.45 eV, respectively. The inclusion of fluorinated BDT units is a very effective approach to lowering the polymer's HOMO level. The SCLC mobilities of PBDTT(ff)‐ttTPD and PBDTT‐ttTPD were determined to be 5.9 × 10^?4 and 3.0 × 10^?4 cm²/Vs, respectively. Polymer solar cell devices prepared with PBDTT(ff)‐ttTPD and PBDTT‐ttTPD as their active layers were found to exhibit power conversion efficiencies of 7.45 and 6.79% with open circuit voltages of 0.98 and 0.84 V, respectively. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 2506–2512     

Short synthesis of phenylpropanoid glycosides calceolarioside-B and eutigoside-A

A convenient 4-step synthesis of calceolarioside-B 1 and eutigoside-A 2 in high overall yield is described. The key step involved the regioselective, Me₂SnCl₂-catalyzed O-6 acylation of unprotected 2-phenylethyl-β-d-glucosides 5a–b with cinnamoyl chlorides 6a–b in excellent yields. Acylation at O-6 is selective with the acid chlorides used. This work serves as a model for the convenient synthesis of phenylpropanoid glycosides acylated at O-6.     

The Ni3Al–Al2O3/TiC cermet formation behavior with TiH2 base ball-milled powders with Ni,Al, and C during spark plasma sintering

Research on Chemical Intermediates - The development of new binder matrices and a fine hard phase have been studied in order to improve the properties of cermet material because TiC has a low...     

Stereoselective lithiation and alkylation and aldol reactions of chiral 5-methyl-3-(o-aryl)-oxazolidinones

Alkylation and aldol reactions carried out on axially chiral, diastereoenriched oxazolidinedione derivatives were found to be highly stereoselective with respect to substitution at the 5-position of the oxazolidindione ring. Thus, diastereoenriched 5-methyl-3-(o-iodophenyl)-2-thioxo-4-oxazolidinone and 5-methyl-3-(o-aryl)-2,4-oxazolidinediones were prepared and lithiated at C-5 of the oxazolidine ring and the subsequent electrophilic quench with alkyl halides or benzaldehyde yielded products with the same diastereomer ratios as the starting materials.     

Identification of novel ligands for the Z-DNA binding protein by structure-based virtual screening

We describe the first discovery of small molecules that bind to the Z-DNA binding domain of human ADAR1 (Adenosine Deaminase Acting on RNA 1) by structure-based virtual screening of chemical database. These molecules bind to Z-DNA binding domain to inhibit the interaction with the Z-DNA. Many viruses have Z-DNA binding proteins, which are structurally similar to Z-DNA binding domain of human ADAR1, and the ability of Z-DNA binding protein to bind the Z-DNA is essential for their pathogenicity. Therefore, the molecules identified in this study may serve as novel leads for the design of agents that inhibit biological functions of those pathogenic viruses.     

Preparation and characterization of antimicrobial polycarbonate nanofibrous membrane

Electrospinning of polycarbonate (PC)/chloroform solution with quaternary ammonium salt (benzyl triethylammonium chloride, BTEAC) was investigated to develop antimicrobial nanofibrous membranes for ultrafiltration. With BTEAC additive, ultrafine PC fibers were continuously generated and densely mounted without the blockage of spinning tip on electrospinning. When small amounts of BTEAC were added to the PC solution, the average diameter was also decreased from several micrometers to submicron range. It was found that the conductivity of the PC solution was a major parameter affecting the morphology and diameter of the electrospun PC fibers as well as the electrospinnability of PC. The nanofibrous membranes electrospun from the PC solution with BTEAC exhibited better excellent antimicrobial activity than those prepared without BTEAC. The PC nanofibrous filter shows a good filtration efficiency to satisfy the criterion of HEPA filter, and the pressure drop of the PC filters are within the normal range. Therefore, PC nanofibrous membrane showed a great potential as a candidate for ultrafiltration, compared to a commercial HEPA filter.     

Hydrothermal Synthesis of a New Vanadium Tellurate(VI) with a Novel Chain Structure: (NH4)4{(VO2)2[Te2O8(OH)2]}·2H2O

A new ammonium vanadium tellurate, (NH₄)₄{(VO₂)₂[Te₂O₈(OH)₂]}·2H₂O ( 1 ) was hydrothermally synthesized and characterized by elemental analyses, IR spectrum, TG analysis, and single crystal X–ray diffraction. Compound 1 crystallizes in the monoclinic system, space group P2₁/n, a = 7.3843(15) Å, b = 17.111(3) Å, c = 7.3916(15) Å, β = 118.88(3)°, V = 817.9(3) ų, Z = 2, R1 (I>2σ(I)) = 0.0235, wR2 (all data) = 0.0462. The structure of 1 consists of infinite anionic chains, {(VO₂)₂[Te₂O₈(OH)₂]}^4? which contain octahedral VO₆ and TeO₅OH units. Each octahedral VO₆ and TeO₅OH unit is connected by sharing an edge to form V₂O₁₀ and Te₂O₈(OH)₂ binuclear units. The V₂O₁₀ and Te₂O₈(OH)₂ binuclear units are alternatively connected to one another, creating complete infinite {(VO₂)₂[Te₂O₈(OH)₂]}^4? chains along the c direction. The anionic chains are separated by ammonium cations and water molecules that link the chains through a network of hydrogen bonds. In addition, the structure contains an extended network of O–H·····O hydrogen bonds between the chains.     

The control of structure in emulsion polymerization

Free-radical addition polymerization can be carried out using four different processes: mass or bulk, solution, suspension, and emulsion polymerization. Of these four processes, emulsion polymerization is unique because it is a heterogeneous process, in which the polymerization reactions can take place in three different sites: in the continuous aqueous phase, on the surface of growing particles, and within the growing particles. This unique feature of emulsion polymerization offers many possibilities for designing different polymers and latexes: e.g., high-molecular-weight polymers, uniform copolymers, copolymers of difficult-to-copolymerize monomers, functionalized (surface-modified) latexes, uniform size latex particles, grafted latexes, and structured latexes having core-shell, microdomain structures, interpenetrating polymer networks, etc. This paper will describe several aspects of the control of structure in emulsion polymerization.     

Modeling of Adsorption in Finite Cylindrical Pores by Means of Density Functional Theory

Adsorption of argon at its boiling point in finite cylindrical pores is considered by means of the non-local density functional theory (NLDFT) with a reference to MCM-41 silica. The NLDFT was adjusted to amorphous solids, which allowed us to quantitatively describe argon adsorption isotherm on nonporous reference silica in the entire bulk pressure range. In contrast to the conventional NLDFT technique, application of the model to cylindrical pores does not show any layering before the phase transition in conformity with experimental data. The finite pore is modeled as a cylindrical cavity bounded from its mouth by an infinite flat surface perpendicular to the pore axis. The adsorption of argon in pores of 4 and 5 nm diameters is analyzed in canonical and grand canonical ensembles using a two-dimensional version of NLDFT, which accounts for the radial and longitudinal fluid density distributions. The simulation results did not show any unusual features associated with accounting for the outer surface and support the conclusions obtained from the classical analysis of capillary condensation and evaporation. That is, the spontaneous condensation occurs at the vapor-like spinodal point, which is the upper limit of mechanical stability of the liquid-like film wetting the pore wall, while the evaporation occurs via a mechanism of receding of the semispherical meniscus from the pore mouth and the complete evaporation of the core occurs at the equilibrium transition pressure. Visualization of the pore filling and empting in the form of contour lines is presented.     

Sorption Equilibria and Kinetics of Hydrocarbons onto Activated Carbon Samples Having Different Micropore Size Distributions

This paper deals with the prediction of adsorption equilibrium and kinetics of hydrocarbons onto activated carbon samples having different micropore size distribution (MPSD). The microporous structure of activated carbon is characterised by the distribution of slit-shaped micropores, which is assumed to be the sole source of surface heterogeneity. The interaction between adsorbate molecule and pore walls is described by the Lennard-Jones potential theory. Different adsorbates have access to different pore size range of activated carbon due to the size exclusion, a phenomenon could have a significant influence on both multicomponent equilibria and kinetics. Activated carbons with three different MPSDs are studied with ethane and propane as the two model adsorbates. The Heterogeneous Macropore Surface Diffusion model (HMSD) is employed to simulate adsorption kinetics. The simulation results show that the MPSD is an important factor affecting both the multicomponent equilibria and kinetics.