Design of new catalysts for ecological high-quality transportation fuels by combinatorial computational chemistry and tight-binding quantum chemical molecular dynamics approaches

Recently, we introduced a concept of combinatorial chemistry to computational chemistry and proposed a new method called “combinatorial computational chemistry”, which enables us to perform a theoretical high-throughput screening of catalysts. In the present paper, we reviewed our recent application of our combinatorial computational chemistry approach to the design of new catalysts for high-quality transportation fuels. By using our combinatorial computational chemistry techniques, we succeeded to predict new catalysts for methanol synthesis and Fischer–Tropsch synthesis. Moreover, we have succeeded in the development of chemical reaction dynamics simulator based on our original tight-binding quantum chemical molecular dynamics method. This program realizes more than 5000 times acceleration compared to the regular first-principles molecular dynamics method. Electronic- and atomic-level information on the catalytic reaction dynamics at reaction temperatures significantly contributes the catalyst design and development. Hence, we also summarized our recent applications of the above quantum chemical molecular dynamics method to the clarification of the methanol synthesis dynamics in this review.     

NiZnCu Ferrite Thick Film with Nano Scale Crystallites Formed by the Aerosol Deposition Method

This paper describes the magnetic properties of NiZnCu ferrite film deposited at room temperature by an aerosol deposition method (ADM). The thickness of the film was 6 μm and the deposition rate was estimated as 2 μm/min. The microstructure of as-deposited at room temperature films consists of randomly oriented nanocrystallites with a size of 20 nm. As-deposited and annealed films exhibited the following magnetic properties: intensity of magnetization M _s= 0.147 T (117 emu/cm³), coercivity H _c= 40.58 kA/m (510 Oe); and M _s= 0.3 T (250 emu/cm³), H _c= 14.95 kA/m (188 Oe), respectively.     

Impact fracture behavior of ethylene ionomer and structural change after stretching

We carried out tensile impact test and very low speed tensile test on ethylene‐based Ionomers (E/15wt %MAA) to clarify the relation between impact toughness and high‐ordered structure. We also studied the changes in high‐ordered structure under deformation by observing Differential Scanning Calorimetory (DSC) and Small‐Angle X‐ray Scattering (SAXS) of fractured surface. Na Ionomers showed ductile fracture in both high speed tensile impact (3 m/s) and very low speed tensile (2 mm/min). The disappearance of secondary melting point (Ti) in Na Ionomers was due to the destruction of ordered structure surrounding the ionic aggregate. Similar behavior was observed in 60% (or less) neutralized Zn Ionomers. However, 80% neutralized Zn Ionomer showed brittle failure in high‐speed tensile impact, and Ti did not disappear. SAXS studies of Na and Zn Ionomers after fracture, show no change both after molding (no aging) and after aging. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1712–1720, 2001     

Nickel‐Catalyzed Suzuki–Miyaura Coupling of a Tertiary Iodocyclopropane with Wide Boronic Acid Substrate Scope: Coupling Reaction Outcome Depends on Radical Species Stability

We describe a nickel‐catalyzed Suzuki–Miyaura arylation of a tertiary iodocyclopropane with arylboronic acids; this is an efficient and convergent strategy for providing various enantioenriched arylcyclopropanes with a quaternary stereogenic center. This is the first metal‐catalyzed coupling between a tertiary alkyl electrophile and a wide range of aromatics, including heteroaromatics. We found that the outcome of the Ni‐catalyzed coupling with halides as electrophiles was dependent on the stability of the radical species formed during the reaction. The use of tert‐butyl alcohol (t‐BuOH) as the reaction solvent was very effective, because of its stability under the radical‐generating reaction conditions.

     

Direct Injection of CRISPR/Cas9-Related mRNA into Cytoplasm of Parthenogenetically Activated Porcine Oocytes Causes Frequent Mosaicism for Indel Mutations

Some reports demonstrated successful genome editing in pigs by one-step zygote microinjection of mRNA of CRISPR/Cas9-related components. Given the relatively long gestation periods and the high cost of housing, the establishment of a single blastocyst-based assay for rapid optimization of the above system is required. As a proof-of-concept, we attempted to disrupt a gene (GGTA1) encoding the α-1,3-galactosyltransferase that synthesizes the α-Gal epitope using parthenogenetically activated porcine oocytes. The lack of α-Gal epitope expression can be monitored by staining with fluorescently labeled isolectin BS-I-B₄ (IB4), which binds specifically to the α-Gal epitope. When oocytes were injected with guide RNA specific to GGTA1 together with enhanced green fluorescent protein (EGFP) and human Cas9 mRNAs, 65% (24/37) of the developing blastocysts exhibited green fluorescence, although almost all (96%, 23/24) showed a mosaic fluorescent pattern. Staining with IB4 revealed that the green fluorescent area often had a reduced binding activity to IB4. Of the 16 samples tested, six (five fluorescent and one non-fluorescent blastocysts) had indel mutations, suggesting a correlation between EGFP expression and mutation induction. Furthermore, it is suggested that zygote microinjection of mRNAs might lead to the production of piglets with cells harboring various mutation types.     

Possibilities of the Formation of Enol-Ethers in Lignin by Soda Pulping

In the alkaline decomposition of a β-O-4 type lignin model compound (erythro-guaiacylglycerol-β-guaiacyl ether, compound 1), an isomeric pair of C₆C₂ enol-ether (2-methoxy-4-[2-(2-methoxyphenoxy)-vinyl]-phenol, compound 2) was detected as the main decomposition product with no trace of C₆C₃ enol-ether (4-[3-hydroxy-1-(2-methoxyphenoxy)-propenyl]-2-methoxy-phenol, compound 3) or other dimers. In contrast, compound 2 was not detected in the alkaline decomposition products of compound 3. Under alkaline conditions, the γ-hydroxymethyl group of compound 3 was reduced to form 2-methoxy-4-[1-(2-methoxyphenoxy)-propenyl]-phenol (compound 4). In the HSQC analysis of soda lignin, the formation of substructures of C₆C₂ type enol-ether (related to compound 2) was confirmed. However, no substructures related to compound 4, which could be formed if a substructure of C₆C₃ type enol-ether was formed under alkaline conditions, were detected. Therefore, it could be concluded that C₆C₃ type enol-ethers could not be intermediates of alkaline decomposition products of lignin.     

125Te, 27Al, and 71Ga NMR Study of M2O3–TeO2 (M = Al and Ga) Glasses

The structures of M₂O₃–TeO₂ (M = Al and Ga) glasses have been investigated by means of ¹²⁵Te, ²⁷Al, and ⁷¹Ga NMR spectroscopies. The structural units of respective cations in M₂O₃–TeO₂ glasses were quantitatively analyzed. The fractions of TeO₄ trigonal bipyramid, AlO₆ and GaO₆ octahedra decreased and those of TeO₃ trigonal pyramid, AlO₄, AlO₅, and GaO₄ polyhedra increased with increasing M₂O₃ content. Based on the local structures around Te, Al, and Ga atoms, the structure models of M₂O₃–TeO₂ glasses were proposed.     

Measurement of High-Temperature Elastic Properties of Ceramics Using a Laser Ultrasonic Method

Young's modulus and Poisson's ratio of SiC ceramics at temperatures >1400°C were obtained using a laser ultrasonics method that included a Fabry-Pérot interferometer (LUFP). At temperatures <1000°C, Young's modulus and Poisson's ratio measured using the LUFP method agreed well with those measured using standard contact methods, such as the resonance method and the ultrasonic pulse method. These results showed that the LUFP method is a powerful tool for measuring high-temperature elastic properties of advanced ceramics in a noncontact manner.     

Acceleration of the Rate of Silver Nanoparticle Formation Using Microbubbles in a Sonochemical Process

The effect of the addition of microbubbles on the formation of silver nanoparticles produced in an ultrasonic radiation-mediated process was investigated. The addition of microbubbles with an area-based median diameter of 26.0?µm and a bubble volume density of 0.18?cm³/L significantly increased the silver nanoparticle formation rate during the sonochemical process. The size distribution of the silver nanoparticles was largely unaffected by the addition of the microbubbles. The influence of changes in the microbubble volume density on the formation of the silver nanoparticles was also investigated; it was confirmed that the rate of formation of the silver nanoparticles increased moderately with increasing volume density. The gradient in absorption spectra was approximately 30 times larger for the case when microbubbles (median diameter: 28.3?µm) were added at 0.74?cm³/L, compared with the case without microbubbles. The results suggested that the microbubbles provided reaction sites similar to cavitation bubbles in the ultrasonic reaction.