Electrochemical performance of LaNi0.6Co0.4O3-δ–Ce0.9Gd0.1O1.95 composite electrode and evaluation of its effective reaction length

Journal of Solid State Electrochemistry - The electrochemical properties of LaNi0.6Co0.4O3-δ–Ce0.9Gd0.1O1.95 composite electrodes as a function of temperature and p(O2) were investigated...     

Design of a Photocatalytic [2+2] Cycloaddition Reaction Using Redox-Tag Strategy

The design of photocatalytic processes is important for a sustainable society. Key to these photocatalytic reactions is electron transfer. This article is focused on titanium dioxide photocatalyzed organic synthesis and the design of a new [2+2] cycloaddition reaction based on the electron transfer process. Electron transfer - not only between the substrate and the photocatalyst but also inter- and intramolecularly – is crucial for the reaction design. Radical cations were generated by the photocatalyst and trapped by alkenes. The resultant cyclobutyl radical cations were immediately reduced by the aryl rings via intramolecular electron transfer to obtain cyclobutane rings. The outcome of the reaction was controlled by substitution of the aryl ring and the linker connecting the aryl ring to the enol ether. The carefully designed substrates were highly effective for photocatalytic cycloaddition.     

O- and N-Glycosidation of d-glycals using Ferrier rearrangement under Mitsunobu reaction conditions. Application to N-nucleoside synthesis

We have disclosed the reaction of 3-hydroxy free glycals with O- or N-nucleophiles under Mitsunobu reaction conditions proceeded to produce 2,3-unsaturated glycosides in good to high yield and moderate stereoselectivity. The reaction would take place via allyloxycarbenium ion.     

Carrier mobility of iron oxide nanoparticles supported on ferroelectrics studied by Mössbauer spectroscopy

⁵⁷Fe Mössbauer spectroscopy was performed on two types of Fe oxide nanoparticles supported on a typical ferroelectric, BaTiO3. It was found that the valence state of FeO nanoparticles changed to a mixed 2+/3+ state at high temperature where BaTiO₃ shows paraelectric behaviour. We attribute this phenomenon to the fluctuation of electric dipoles which realizes carrier injection into the Fe oxides. This is the first report which discusses a dynamical valence state of transition metal oxides supported on ferroelectrics.     

Unexpected chain length dependence on a chiral memory effect of ‘meta-ethynylpyridine’ oligomers

The chain length dependence involving a chiral memory effect of 2,6-pyridylene ethynylene oligomers ‘meta-ethynylpyridines’ was investigated. The meta-ethynylpyridine oligomers associated with octyl β-d-glucopyranoside form a helical complex giving induced CD; the induced chirality could be memorized with the help of Cu(OTf)₂ as an additive. Contrary to our expectations, the study of the length dependence revealed that the 12-meric oligomer showed a more sustainable chiral memory effect than those observed in both of the shorter 6-meric and longer 18-meric oligomers.     

Synthesis,crystal structures,spectral, electrochemical and magnetic properties of di-µ-phenoxido-bridged dinuclear copper(II) complexes with N-salicylidene-2-hydroxybenzylamine derivatives: axial coordination effect of dimethyl sulphoxide molecule

The template reaction of salicylaldehyde and its substituted derivatives and 2-hydroxy-5-bromobenzylamine or 2-hydroxy-5-chlorobenzylamine with copper(II) acetate in dimethyl sulphoxide (dmso) afforded eight dinuclear Cu(II) complexes, [Cu₂(L)₂(dmso)₂] (H₂ L = N-salicylidene-2-hydroxy-5-bromobenzylamine, N-salicylidene-2-hydroxy-5-chlorobenzylamine and their 5-bromo, 5-nitro and 5-methyl-substituted salicylidene derivatives). These Cu(II) complexes were characterised by IR and UV-VIS-NIR spectroscopy, electric conductivity, cyclic voltammetry, and temperature dependence of magnetic susceptibilities (4.5–300 K). In the THF solution, the complexes are nonelectrolytes and exhibit a characteristic CT band due to phenoxido-bridging at 360–384 nm. In the cyclic voltammograms, an irreversible reduction process was observed at ?1.18–1.54 V vs Fc/Fc⁺. Single-crystal X-ray crystallography revealed that two Cu(II) ions were bridged by the two phenoxido-oxygen atoms of the two Schiff-base ligands with axial coordination of dmso molecules forming a square pyramid with a Cu-Cu distance of 3.0628(8)–3.0931(6) °A. In accordance with the crystal structures, the magnetic interaction between the two Cu(II) ions is relatively anti-ferromagnetic with ?2J value of 386–575 cm^?1. The axial coordination effect of the dmso molecule was discussed in relation to the correlation between the Cu-O-Cu angle and the ?2J value.     

Development of convergent synthetic method for saccharide-linked ethynylpyridine foldamers by Huisgen reaction

Based on ‘click chemistry’, the new convergent synthesis to a variety of saccharide-linked 2,6-pyridylene ethynylene ‘ethynylpyridine’ foldamers was developed. Ethynylpyridine 6-, 9-, and 12-meric blocks were linked with 1,7-octadiyne linker block by Sonogashira reaction, and joined with azido group-introduced glucoside, galactoside, and mannoside templates by Huisgen reaction. The resulting saccharide-linked ethynylpyridine foldamers exhibited typical circular dichroism to indicate the formation of a helical structure by intramolecular hydrogen bonds.     

In situ Raman imaging of osteoblastic mineralization

Hydroxyapatite (HA) is synthesized at early stages of bone formation by osteoblasts. Nondestructive observation of early stages of osteoblastic mineralization provides crucial information for biological mechanism of bone formation. Raman microscopy serves as an ideal tool to observe the osteoblastic mineralization process because it shows the chemical information of the sample at a minimally invasive level. In addition, HA is a marker for osteoblastic mineralization, and HA Raman signal is strong enough to identify mineralized spots in osteoblasts. In this research, we visualized the distribution of HA in cultured mouse osteoblasts by Raman imaging and observed the location of the mineralized spots in the culture. We monitored HA Raman signal from osteoblast culture for 3 days after administrating the osteogenic differentiation medium and observed Raman signal associated with HA. We identified mineralized spots of KUSA‐A1 by Raman imaging constructed from the distribution of HA Raman signal. We successfully visualized the distribution of the mineralized spots in the culture of KUSA‐A1. We compared our Raman images with Alizarin red S staining assay, which was a conventional method to evaluate the mineralization process. Raman imaging of the KUSA‐A1 culture visualized the mineralized spots more accurately than Alizarin red S staining assay. Raman imaging of HA serves as a powerful tool to identify the mineralized spots in an in vitro culture of osteogenic lineage cells. Copyright © 2014 John Wiley & Sons, Ltd.