Systematic enantiomeric separation of [60]fullerene bisadducts possessing an inherent chiral addition pattern

The optical resolution of trans-2 and trans-3 [60]fullerene bisadducts with an inherent chiral addition pattern, modified by Bingel reaction, cycloaddition by benzyne, Prato reaction, and cycloaddition by o-quinodimethane, was systematically investigated by using chiral HPLC columns (Chiralcel OD and Chiralpak AD). The chiroptical properties of enantiomers separated were also examined.     

Photochemical Ionic-Conductivity Switching Systems of Photochromic Crown Ethers for Information Technology

Design of two types of ion-conducting systems using photochromic crown ethers as the photocontrol agents is described; one type is based on the phase transition of azobenzene derivatives induced by their photoisomerization and the other based on the molecular control of metal ion complexation by crowned spirobenzopyrans. The photoresponsive ion-conducting systems are applicable to electrostatic imaging and photorefractive materials.     

Addition of alkyl radicals, generated from carboxylic acids via photochemical decarboxylation, to glyoxylic oxime ether: a mild and efficient route to α-substituted α-aminoesters

Radical addition to a glyoxylic oxime ether was accomplished under mild conditions using an alkyl radical generated from a free carboxylic acid via photochemical decarboxylation. The photoreaction provided an efficient route to α-substituted α-aminoesters from carboxylic acids and oxime ether.     

Preparation of anisotropic silica nanoparticles via controlled assembly of presynthesized spherical seeds

A facile solution process for the preparation of anisotropic silica nanoparticles (ASNPs) is presented. ASNPs are prepared via controlled self-assembly of spherical silica seeds (22 nm) in alcohol-water mixed media, followed by their in situ fixation and overgrowth with tetraethoxysilane (TEOS). Ethanol and L-arginine (Arg) are used to modify the dielectric constant and ionic strength of the reaction media, by which seed assembly is controlled through the adjustment of electrostatic interaction. Ethanol and Arg also serve as a cosolvent and a catalyst for hydrolysis and condensation of TEOS, respectively, which enables us to produce ASNPs in a simple one-pot process. In addition to ASNPs with wormlike structures, different kinds of NPs (bimodal spherical NPs, monodisperse spherical NPs, and spherical aggregates) have also been obtained by changing the concentrations of ethanol and Arg. The length, thickness, or both of ASNPs are controlled systematically by varying the concentrations of Arg, seed NPs, and TEOS. Other alcoholic cosolvents, such as methanol, 1-propanol, 2-propanol, and t-butanol, are also effective to give ASNPs when the dielectric constant of the alcohol-water mixed media is properly adjusted, showing the versatility of the present method.     

Electrochemical performance of nanocomposite LiMnPO4/C cathode materials for lithium batteries

A LiMnPO₄/C composite cathode was prepared by a combination of spray pyrolysis and wet ball milling. The cathode showed stable performance at various cutoff voltages up to 4.9 V. The cutoff voltage increase up to 4.9 V allowed the achievement of a high discharge capacity in galvanostatic charge–discharge tests. The discharge capacities of 153 mAh g^?1 at 0.05 C and 149 mAh g^?1 at 0.1 C were achieved at room temperature; the trickle-mode discharge capacities at room temperature were 132, 120 and 91 mAh g^?1 at 0.1, 1 and 5 C discharge rates, respectively. The cell exhibited a good rate capability in the galvanostatic cycling up to 5 C discharge rates at both ambient temperature and 50 °C.     

Selective synthesis of organogold magic clusters Au54(C≡CPh)26

Organogold clusters Au(54)(C(2)Ph)(26) were selectively synthesized by reacting polymer-stabilized Au clusters (1.2 ± 0.2 nm) with excess phenylacetylene in chloroform.     

Photo-impulsive reactions in the electronic ground state without electronic excitation: non-photo, non-thermal chemical reactions

Allyl phenyl ether has an absorption band in the ultraviolet region (λ < 400 nm); therefore, irradiation with few-optical-cycle ultraviolet pulses (λ = 360-440 nm) causes a transition to the ultraviolet band, which leads to an electronic state and a photo-Claisen rearrangement (radical reaction) in the electronic excited state. However, the reaction scheme of allyl phenyl ether under irradiation with few-optical-cycle visible pulses (λ = 525-725 nm) was determined to be same as that of the thermal Claisen rearrangement ([3,3]-sigmatropic rearrangement), which is symmetry-allowed in the electronic ground state. Photo-excitation with few-optical cycle visible pulses below the absorption band induces a photo-impulsive reaction in the electronic ground state without electronic excitation, of which the trigger scheme is different from that of photoreaction or thermal-reaction. The photo-impulsive reaction in the electronic ground state is highly possible as a novel reaction scheme.     

Evidence of Nonelectrochemical Shift Reaction on a CO-Tolerant High-Entropy State Pt-Ru Anode Catalyst for Reliable and Efficient Residential Fuel Cell Systems

A randomly mixed monodispersed nanosized Pt-Ru catalyst, an ultimate catalyst for CO oxidation reaction, was prepared by the rapid quenching method. The mechanism of CO oxidation reaction on the Pt-Ru anode catalyst was elucidated by investigating the relation between the rate of CO oxidation reaction and the current density. The rate of CO oxidation reaction increased with an increase in unoccupied sites kinetically formed by hydrogen oxidation reaction, and the rate was independent of anode potential. Results of extended X-ray absorption fine structure spectroscopy showed the combination of N(Pt-Ru)/(N(Pt-Ru) + N(Pt-Pt)) ? M(Ru)/(M(Pt) + M(Ru)) and N(Ru-Pt)/(N(Ru-Pt) + N(Ru-Ru)) ? M(Pt)/(M(Ru) + M(Pt)), where N(Pt-Ru)(N(Ru-Pt)), N(Pt-Pt)(N(Ru-Ru)), M(Pt), and M(Ru) are the coordination numbers from Pt(Ru) to Ru(Pt) and Pt (Ru) to Pt (Ru) and the molar ratios of Pt and Ru, respectively. This indicates that Pt and Ru were mixed with a completely random distribution. A high-entropy state of dispersion of Pt and Ru could be maintained by rapid quenching from a high temperature. It is concluded that a nonelectrochemical shift reaction on a randomly mixed Pt-Ru catalyst is important to enhance the efficiency of residential fuel cell systems under operation conditions.