Site-specific phonon density of states discerned using electronic states

We have performed the measurement of the site-specific phonon densities of states (PDOS) discerned using electronic states. As far as we know, no general method could give the site-specific PDOS, although oscillating properties of the individual atoms in nonequivalent positions are not necessarily equivalent. However, the combination of the energy and time domain measurements of the nuclear resonant scattering of synchrotron radiation allows the identification of site-specific PDOS. We measured the site-specific PDOS of iron atoms in magnetite, which is a mixed valent compound, and the difference between partial phonon densities of the iron sites was clearly observed.     

Highly selective growth of vertically aligned double‐walled carbon nanotubes by a controlled heating method and their electric double‐layer capacitor properties

Vertically aligned double‐walled carbon nanotubes (DWCNTs) with the highest selectivity of 90% were synthesized by a controlled heating method and their electric double‐layer capacitor characteristics were evaluated. DWCNT arrays had a specific capacitance of 83 F/g, which is one of the highest values among CNT arrays in a nonaqueous solution and is almost equivalent to that for single‐walled CNT (SWCNT) arrays reported previously. At the same specific capacitance, DWCNTs with superior structural properties are more promising for practical capacitors than SWCNTs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis of compounds with juvenile hormone activity—XVII : A stereoselective synthesis of dl-C17-Cecropia juvenile hormone

A stereoselective synthesis of the title compound (2) was accomplished using a coupling reaction of a C₆-unit (4) with a C₁₀-unit (8) as the key-step.     

Application of long range j c-h resolved 2d spectroscopy (lrjr) in structural elucidation of natural products. The structure of oxirapentyn

The structure of a fungal metabolite, oxyrapentyn has been determined as shown in Fig. 7 by application of a new NMR technique, long range J C-H resolved 2D spectroscopy (LRJR).     

Structural studies of polyethers. IX. Planar zigzag modification of poly(ethylene oxide)

A new crystal modification was found in poly(ethylene oxide) stretched about two-fold after necking at room temperature. An x-ray diffraction analysis indicated that the planar zigzag molecule passes through a triclinic unit cell with parameters α = 4.71 Å, b = 4.44 Å, c (fiber axis) = 7.12 Å, α = 62.8°, β = 93.2°, and γ = 111.4°. The space group is P1 ?C_i¹. Packing of the molecule is very similar to that of monoclinic polyethylene.     

The [2,3]Wittig rearrangement of 2-alkenyloxyacetic acids and its applications to the stereocontrolled synthesis of β, γ-unsaturated aldehydes and conjugated dienoic acids

Dianions generated from 2-alkenyloxyacetic acids readily undergo the [2,3]sigmatropic rearrangement uhich can constitute the versatile synthetic sequences for the stereocontrolled synthesis of β,γ-unsaturated aldehydes and conjugated dienoic acids.     

Kinetic resolution of rac-phenylalanine by stereoselective complexation to a chiral cobalt complex through pi-pi stacking interaction

A cobalt(III) complex with chiral ligand, H2cpel (N-carboxymethyl-N-pyridylethyl-l-leucine), was prepared for chiral recognition of amino acids. Through the competitive coordination of racemic phenylalanine to the chiral cobalt complex, [Co(cpel)(CO(3))](-) (1), enantioselective recognition was achieved on the ternary complex, which was determined on the basis of HPLC analysis with a chiral column. The formation rate for the [Co(cpel)(l-phe)] complex (2) was 6-times superior to that of [Co(cpel)(d-phe)] (3). The preferential formation of 2 might be illustrated by the interligand pi-pi stacking interaction. Crystal structural analysis for 2 and 3 revealed that aromatic rings, pyridine ring of CPEL and phenylalanine sidechain, in 2 were very close each other but those in 3 were far apart. Such interligand aromatic interaction in 2 was also examined by the use of (1)H NMR spectra.     

An accurately-constructed structural model for an active site of Fe-containing superoxide dismutases (Fe-SODs)

A novel structural model, [Fe(bpga)(N(3))(OCH(3))] (1) (BPGA: bis(6-pivalamido-2-pyridylmethyl)(carboxy-methyl)amine), for an active site of Fe-containing SOD enzyme with N(3)(-) has been accurately designed and prepared, which has been characterized by X-ray structure analysis and UV-vis, ESR, and IR spectroscopies. Reaction of 1 with acid/base in methanol has shown that the superoxide-accessible site is the N(3)(-)-coordination site in the equatorial plane.     

A new type of bromide anion conducting solid

A new type of bromide anion conducting solid electrolyte was designed with the solid electrolyte based on oxybromide; the oxybromide lends unique characteristics of thermal stability and water insolubility (5.6 mg in 100 g of water at 25 degrees C) to the electrolyte which shows the highest Br- anion conductivity reported above 500 degrees C.