Site‐Selective Iron(III) Chloride‐Catalyzed Arylation of 4‐Aryl‐4‐methoxy‐2,5‐cyclohexadienones for the Synthesis of Polyarylated Phenols

The iron(III) chloride‐catalyzed Friedel–Crafts arylation of 4‐aryl‐4‐methoxy‐2,5‐cyclohexadienones, which were easily prepared by the phenyliodine(III) diacetate (PIDA)‐mediated oxidation of 4‐arylphenols in methanol, proceeded site‐selectively to form meta‐terphenyl (2,4‐diarylphenol) derivatives in good yields. The subsequent PIDA‐mediated oxidation and iron(III) chloride‐catalyzed Friedel–Crafts arylation of the resulting products gave the corresponding 2,4,6‐triarylphenol derivatives. The present method provides useful highly substituted polyarylated compounds.

     

Alignment of a nematic liquid crystal on nano‐grooved material

We demonstrate the alignment characteristics of a nematic liquid crystal on the surface of a nanoimprinted material that is a functionally graduated composite suitable for the alignment of a liquid crystal on a groove surface processed by nanoimprinting lithography. With the electro‐optic characteristics shown in twisted nematic and in‐plane switching modes, the potential liquid crystal applications are examined. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Structural,Thermal and Magnetic Properties of Thin Metal Films and Adsorbate–Substrate Systems Studied by XAFS and XMCD

Thin metal films often exhibit interesting properties that are essentially different from the bulk ones. XAFS (X-ray absorption fine structure) and XMCD (X-ray magnetic circular dichroism) techniques are quite suitable to investigate structural, thermal and magnetic properties of thin metal films. In this proceeding, we will present following two topics concerning structural and magnetic properties of adsorbates on thin metal films. The first one is the adsorption geometry of SO₂ on a 1-monolayer (ML) Pd thin film grown on a Ni(111) single crystal. It was found by S K-edge XAFS that SO₂ is lying flat on 1-ML Pd/Ni(111). This result is not similar to the bulk Pd surface but to the bulk Ni one. This finding indicates significant modification of the electronic structure of the 1-ML Pd film compared to the bulk one. The second topic is the magnetic moment induced on CO adsorbed on Ni epitaxial films grown on Cu(001). The O K-edge XMCD results revealed that in the perpendicularly magnetized 10-ML Ni film the orbital moment of CO is parallel to the substrate Ni magnetization, while it is antiparallel in the in-planar magnetized 6-ML and thick (>100 ML) films. The origin of the induced orbital moment at CO is discussed.     

Spray-dry synthesis of β-Cu1.8Zn0.2V2O7 ceramic fine particles showing giant negative thermal expansion

We used spray-dry method to synthesize fine powder of β-Cu_1.8Zn_0.2V₂O₇ showing large negative thermal expansion (NTE) linearly to temperature over a wide temperature range. The NTE of β-Cu_1.8Zn_0.2V₂O₇ is produced by microstructures consisting of voids and anisotropic thermal deformation of crystal grains in ceramics. By reducing the size of the microstructures that produce NTE, large NTE equivalent to that of bulk was realized, even for ceramic particles of about 2 μm size. Comparison with particles produced using a conventional method demonstrates that the particle size distribution is narrow and that the particles are nearly spherical. This achievement is expected to pave the way to use of NTE materials in micrometer-scale control of thermal expansion.     

Profiling and Imaging of Phospholipids in Brains of Abcd1‐Deficient Mice

ABCD1 is a gene responsible for X‐linked adrenoleukodystrophy (X‐ALD), and is critical for the transport of very long‐chain fatty acids (VLCFA) into peroxisomes and subsequent β‐oxidation. VLCFA‐containing lipids accumulate in X‐ALD patients, although the effect of ABCD1‐deficiency on each lipid species in the central nervous system has not been fully characterized. In this study, each phospholipid and lysophospholipid species in Abcd1‐deficient mice brains were profiled by liquid chromatography‐mass spectrometry. Among the phospholipid and lysophospholipid species that are significantly more enriched in Abcd1‐deficient mice brains, VLCFA were present in 75, 15, 5, 4, and 1 species of phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, lysophosphatidylcholine, and lysophosphatidylethanolamine, respectively. Most VLCFA were incorporated at the sn‐1 position of phosphatidylcholine and phosphatidylethanolamine. Among the phospholipid species that are significantly less enriched in Abcd1‐deficient mice brains, odd‐numbered saturated or mono‐unsaturated fatty acyl moieties are contained in all phosphatidylcholine species. In addition, a number of phosphatidylglycerol, phosphatidylinositol, and phosphatidylserine species contained highly unsaturated fatty acyl moieties. Intriguingly, 44:1 phosphatidylcholine with VLCFA was mainly distributed in the gray matter, such as the cortex, but not in the white matter in the cerebrum and cerebellum. These results show that ABCD1‐deficiency causes metabolic alternation of long‐chain fatty acids and VLCFA. Moreover, our results imply a molecular mechanism for the incorporation of saturated or monounsaturated VLCFA into the sn‐1 position of phospholipids, and also indicate that the distribution of phospholipids with VLCFA may correlate with the development of X‐ALD.     

Characteristics and Reactivity of Lignin in Acacia and Eucalyptus Woods

The chemical characteristics of lignin, including the Klason lignin content, acid-soluble lignin content, proportion of the aromatic ring types [syringyl ratio = syringyl/(syringyl + guaiacyl)], and proportion of the diastereomeric forms for the β-O-4 structure [erythro ratio = erythro/(erythro + threo)], and pulpability were investigated for 28 wood samples belonging to the genera Acacia and Eucalyptus. Although the lignin characteristics of these 28 woods varied widely, the chemical characteristics of the two genera could be categorized in two clearly distinguished groups on the basis of the syringyl ratio. Clear negative correlations were observed between both the syringyl and erythro ratios and the total lignin content (sum of the Klason and acid-soluble lignin contents) within each genus. In addition, the syringyl ratio correlated positively with the erythro ratio and acid-soluble lignin content, regardless of the genus. The existence of a clear, high correlation between the syringyl and erythro ratios supports the hypothesis that the aromatic ring type (syringyl ratio) is a decisive factor for controlling the diastereomeric forms of the β-O-4 structure (erythro ratio). Each of the wood samples was also subjected to Kraft pulping, and it was demonstrated that the woods with higher syringyl ratios were easier to delignify. This tendency is reasonably attributed to the high reactivity of the erythro-rich and syringyl-rich β-O-4 structures, and the low lignin content of these syringyl-rich woods.     

Evaluation of hydrogen absorption properties of Ti–0.2 mass% Pd alloy in fluoride solutions

The hydrogen absorption properties of Ti–0.2 mass% Pd (Ti–0.2Pd) alloy in 2.0% and 0.2% acidulated phosphate fluoride (APF) and neutral 2.0% NaF solutions (25 °C) has been evaluated by hydrogen thermal desorption analysis. During the early stage of immersion (120 h) in the 2.0% APF solution, the amount of absorbed hydrogen was lower than 500 mass ppm. A thermal desorption of hydrogen primary appearing with a peak at 500–600 °C and a broad desorption ranging from 100 to 400 °C were observed. In the 0.2% APF solution, the amount of absorbed hydrogen saturated at 100–200 mass ppm; the thermal desorption of hydrogen appeared with a single peak at 550 °C. In the 2.0% NaF solution, hydrogen absorption was negligible even after 1000 h of immersion, although corrosion pits were observed. The results of the present study suggest that the hydrogen absorption of Ti–0.2Pd alloy, as compared with commercial pure titanium, is suppressed in fluoride solutions.     

Rapid separation of shikimic acid from Chinese star anise (Illicium verum Hook. f.) with hot water extraction

Shikimic acid can be rapidly separated (ca. 5 min) from Chinese star anise with hot water extraction at temperatures of 120 °C or higher to obtain recoveries of 100%. Extraction recoveries of shikimic acid close to 97% can be obtained with water at 70 °C using slightly longer extraction times (ca. 10 min) than those at 120 °C. A semi-batch flow apparatus was used to study the effect of temperature, average particle size, water flow rate, and extraction time on the experimental recoveries. For 0.5 g Chinese star anise raw material that contained ca. 8% shikimic acid, 100% recoveries of shikimic acid could be obtained with 60 g water at 150 °C at 15 MPa in 4 min for star anise material having a particle size range from 355 to 600 μm. A one-site kinetic model was found to provide good correlation of the data and the kinetic parameters of the model could be written in terms of linearized contributions in temperature, average particle diameter and flow rate.