Molecular Ionics in Supramolecular Assemblies with Channel Structures Containing Lithium Ions

A novel trilithium compound, Li₃[B(C₆H₄O₂){O(CH₂CH₂O)₃CH₃}₂][N(SO₂CF₃)₂]₂ ( 1 ‐2.0), with solid‐state ionic conductivity was synthesized. The crystal structure of 1 ‐2.0 consists of the one‐dimensional ionic conduction paths. The paths were afforded as a result of the self‐assembled stacking of the component molecules of 1 ‐2.0 with channel structures containing lithium ions. In this supramolecule, one lithium ion holds the component molecules in specific positions to construct a supramolecular structure with thermally stable ionic conduction paths and the others behave as carrier ions exhibiting selective lithium‐ion conductivity. Owing to the existence of both roles for the lithium ions, this electrolyte shows selective lithium‐ion conductivity.     

Proton acceleration to 40 MeV using a high intensity, high contrast optical parametric chirped-pulse amplification/Ti:sapphire hybrid laser system

Using a high-contrast (10(10):1) and high-intensity (10(21) W/cm(2)) laser pulse with the duration of 40 fs from an optical parametric chirped-pulse amplification/Ti:sapphire laser, a 40 MeV proton bunch is obtained, which is a record for laser pulse with energy less than 10 J. The efficiency for generation of protons with kinetic energy above 15 MeV is 0.1%.     

Recent progress in environmental catalytic technology

Recent progress and trends in environmental catalytic technology in Japan are described with emphasis on the catalysts having hybridized functions. In addition to automobile exhaust cleaning, use of environmental catalysts such as titanium oxide photocatalysts is rapidly growing for the control of residential environments, e.g., antimicrobial activity and odor control, as life styles change gradually and the living environment is deteriorating considerably. Many new catalysts are evolving through hybridization of functions. The market of environmental catalyst products in 2005 is estimated 2,000 billion yen/year (photocatalyst: 1,100 billion yen/year).     

Efficient photocleavage of DNA utilising water-soluble lipid membrane-incorporated [60]fullerenes prepared using a [60]fullerene exchange method

Various types of lipid membrane-incorporated C60 with high C60 concentrations can be prepared easily in several hours using the C60 exchange method and the photocleaving activity of cationic lipid membrane-incorporated C60 was appreciably higher than that of the C60.gamma-CDx complex.     

Processing of β-BaB2O4 Thin Films Through Metal Organics

β-BaB₂O₄ (β-BBO) thin films were successfully synthesized by the sol-gel method using metallo-organic compounds. A stable BBO precursor solution was prepared from barium metal and boron triethoxide or 2,4,6-triethoxycyclotriboroxane in a mixture solvent of ethanol and 2-ethoxyethanol. As-precipitated powder formed by hydrolysis of the precursor solutions crystallized to ψ phase, which was transformed to β phase at higher temperatures. The transformation temperatures of powders from ψ to β phase of the ethoxide system and the boroxane system were 600 and 680°C, respectively. The calcination of precursor films in a mixture gas of water and oxygen was found to decrease the crystallization temperature of β-BBO films on Pt sheet substrates. The precursor films prepared from the ethoxide system and the boroxane system crystallized to β-BBO on Pt (111)/glass substrates at 500 and 550°C, respectively. The BBO films on Pt(111)/glass substrates showed the strong (006) preferred orientation. The β-BBO films on Pt(111)/glass substrates showed the second harmonic generation (SHG) of the 532 nm light on irradiation with 1064 nm light. The SH power from the BBO films was correlated with the fundamental power through the square-law proportionality based on the theory. The SHG efficiency of the BBO films was dependent upon the film thickness.     

Design and synthesis of N-terminal cyclic motilin partial peptides: a novel pure motilin antagonist

Motilin antagonist was designed and synthesized on the basis of the structure-activity relationship analysis of porcine motilin that we reported recently. The drug design was performed on a specific concept to reduce a flexibility of peptide conformation of porcine motilin partial peptide by its cyclization. The cyclic peptide was synthesized using Boc (tert-butyloxycarbonyl) solid phase methodology, followed by cyclization using the azide procedure, and tested for the binding activity to motilin receptor and smooth muscle contractile activity. The cyclic peptides 3, 4, and 5 showed antagonistic property on contraction assay (pA2 [the negative logarithm of molar concentration of antagonist causing a 2-hold shift to the right of the concentration-response curve for motilin]: 4.5, 4.34, and 4.04, respectively, in rabbit duodenum) and no contractile activity even at high concentration.     

Reaction of trimethylsilylpropargyl phenyl ether with organoboranes in the presence of sodium methoxide

Silylallenes ($\text{4}$) are selectively prepared from trimethylsilylpropargyl phenyl ether and trialkylboranes by treatment with sodium methoxide.     

Highly permeable mesoporous silica membranes synthesized by vapor infiltration of tetraethoxysilane into non-ionic alkyl poly(oxyethylene) surfactant films

Mesoporous silica membranes were prepared on porous alumina substrates by a vapor infiltration of tetraethoxysilane (TEOS) into a non-ionic poly(oxyethylene) (Brij56) surfactant film. Periodic mesostructured silica membranes were formed on both α- and γ-alumina substrates pre-treated with polystyrene. The polystyrene polymer plugged the pores of the alumina substrates and inhibited the deposition of silica in the alumina pores, resulting in the formation of a very thin silica membrane without a silica/alumina composite layer at the interface between mesoporous silica and the alumina substrates. The calcined mesoporous silica membrane showed very high nitrogen permeance (>10⁻⁶ mol m⁻² s⁻¹ Pa⁻¹). The single gas permeation was governed by the Knudsen diffusion mechanism. The durability of the mesoporous silica membrane against moisture in air was improved by a silylation with trimethylethoxysiliane.