Viscosity Measurement of La3Ga5SiO14 Melt

The viscosity of La₃Ga₅SiO₁₄ melt was measured by a fixed-crucible rotor technique in the range between 1520 and 1596 °C. The melt was found to be Newtonian. The viscosity data ranged between 73 and 97 mPa. s, decreasing with increasing temperature. The activation energy of the viscous flow and the volume of a viscous flow unit estimated from the measured data were 90 kJ/mol and 3 × 10⁻³ nm³, respectively.     

Growth and Characterization of Na2CaGe6O14 Single Crystals

Transparent, crack-free Na₂CaGe₆O₁₄ (NCG) single crystals were successfully grown using the Czcchralski technique. The largest crystal had 30 mm in total length and 18 mm in maximal diameter. Best crystal quality was achieved under low temperature gradient arrangement. The crystal structure of NCG has been refined from single crystal X-ray diffraction data. Some piezoelectric properties of NCG are reported.     

Enhanced Automatic Diameter Control System of Czochralski-grown Crystals

The automatic diameter control system with two ways of the crystal diameter determination is described. The correction of temperature oscillations during the growth process is applied in the describing system. Also, it allows to estimate the crystal quality already during the growth process. The control system is intended for the growth of crystals with different physical properties.     

New methodology for synthesizing polyolefinic graft block copolymers and their morphological features

This paper describes a new synthetic route for polyolefinic graft block copolymers by adopting coupling reaction between terminally hydroxylated polyolefins and maleic anhydride grafted polyolefins. Terminally hydroxylated polypropylene (PP-OH) was coupled with maleic anhydride modified polyethylene (PE-g-MAH) and such ethylene-propylene random copolymer (EPR-g-MAH) to give polyolefinic graft block copolymers (PE-g-PP and EPR-g-PP, respectively). The formation of PE-g-PP was confirmed by enhancement on molecular weight and it brought about distinctive decrease in size of dispersed domain in its phase separation morphology. Occurrence of coupling reaction to give EPR-g-PP was indicated by extreme decrease in its solubility to n-decane and it led to unique morphology demonstrating lamella microstructure that had never been reported for a comparable polyolefin composite.     

Polymacromonomers with polyolefin branches synthesized by free-radical homopolymerization of polyolefin macromonomer with a methacryloyl end group

Polymacromonomers with polyolefin branches were successfully synthesized by free-radical homopolymerization of polyolefin macromonomer with a methacryloyl end group. Propylene-ethylene random copolymer (PER) with a vinylidene end group was prepared by polymerization using a metallocene catalyst. Then, the unsaturated end group was converted to a hydroxy end group via hydroalumination and oxidation. The PER with the hydroxy end group was easily reacted with methacryloyl chloride to produce methacryloyl-terminated PER (PER macromonomer; PERM). The free-radical polymerization of thus-obtained PERM was done using 2,2′-azobis(isobutyronitorile) (AIBN) as a free-radical initiator. From NMR analyses, the obtained polymers were identified as poly(PERM). Based on gel permeation chromatography (GPC), the estimated degree of polymerization (D_p) of these polymers were about 30. Thus, new class of polymacromonomers with polyolefin branches was synthesized.     

AtTrxh3, a Thioredoxin,Is Identified as an Abscisic AcidBinding Protein in Arabidopsis thaliana

Abscisic acid (ABA, 1) is a plant hormone that regulates various plant physiological processes such as seed developing and stress responses. The ABA signaling system has been elucidated; binding of ABA with PYL proteins triggers ABA signaling. We have previously reported a new method to isolate a protein targeted with a bioactive small molecule using a biotin linker with alkyne and amino groups, a protein cross-linker, and a bioactive small molecule with an azido group (azido probe). This method was used to identify the unknown ABA binding protein of Arabidopsis thaliana. As a result, AtTrxh3, a thioredoxin, was isolated as an ABA binding protein. Our developed method can be applied to the identification of binding proteins of bioactive compounds.     

Kinetic resolution of primary amines via enantioselective N-acylation with acyl chlorides in the presence of supramolecular cyclodextrin nanocapsules

The non-enzymatic kinetic resolution of primary amines via enantioselective N-acylation with acyl chlorides was accomplished for the first time by using the selective sequestration of one enantiomer within a supramolecular cyclodextrin (CD) nanocapsule in nonpolar solvents. In addition, the first example of a crystalline structure for an inclusion complex between an acyl chloride and a CD derivative is reported.     

Strongly Luminous Tetranuclear Gold(I) Complexes Supported by Tetraphosphine Ligands,meso‐ or rac‐Bis[(diphenylphosphinomethyl)phenylphosphino]methane

A series of tetragold(I) complexes supported by tetraphosphine ligands, meso‐ and rac‐bis[(diphenylphosphinomethyl)phenylphosphino]methane (meso‐ and rac‐dpmppm) were synthesized and characterized to show that the tetranuclear Au^I alignment varies depending on syn‐ and anti‐arrangements of the two dpmppm ligands with respect to the metal chain. The structures of syn‐[Au₄(meso‐dpmppm)₂X]X′₃ (X=Cl; X′=Cl ( 4 a ), PF₆ ( 4 b ), BF₄ ( 4 c )) and syn‐[Au₄(meso‐dpmppm)₂]X₄ (X=PF₆ ( 4 d ), BF₄ ( 4 e ), TfO ( 4 f ); TfO=triflate) involved a bent tetragold(I) core with a counter anion X incorporated into the bent pocket. Complexes anti‐[Au₄(meso‐dpmppm)₂]X₄ (X=PF₆ ( 5 d ), BF₄ ( 5 e ), TfO ( 5 f )) contain a linearly ordered Au₄ string and complexes syn‐[Au₄(rac‐dpmppm)₂X₂]X′₂ (X=Cl, X′=Cl ( 6 a ), PF₆ ( 6 b ), BF₄ ( 6 c )) and syn‐[Au₄(rac‐dpmppm)₂]X₄ (X=PF₆ ( 6 d ), BF₄ ( 6 e ), TfO ( 6 f )) consist of a zigzag tetragold(I) chain supported by the two syn‐arranged rac‐dpmppm ligands. Complexes 4 d–f , 5 d–f , and 6 d–f with non‐coordinative large anions are strongly luminescent in the solid state (λ_max=475–515 nm, Φ=0.67–0.85) and in acetonitrile (λ_max=491–520 nm, Φ=0.33–0.97); the emission was assigned to phosphorescence from ³[d_σ*σ*σ*p_σσσ] excited state of the Au₄ centers on the basis of DFT calculations as well as the long lifetime (a few μs). The emission energy is predominantly determined by the HOMO and LUMO characters of the Au₄ centers, which depend on the bent ( 4 ), linear ( 5 ), and zigzag ( 6 ) alignments. The strong emissions in acetonitrile were quenched by chloride anions through simultaneous dynamic and static quenching processes, in which static binding of chloride ions to the Au₄ excited species should be the most effective. The present study demonstrates that the structures of linear tetranuclear gold(I) chains can be modified by utilizing the stereoisomeric tetraphosphines, meso‐ and rac‐dpmppm, which may lead to fine tuning of the strongly luminescent properties intrinsic to the Au^I₄ cluster centers.