Molecular bilayer-based superstructures of a fullerene-carrying ammonium amphiphile: structure and electrochemistry

The synthesis of a water-soluble C60-carrying single-chain ammonium amphiphile, 10- (N-methyl-2-fulleropyrrolidyl)decyltrimethylammonium bromide (1) as well as the characterization of aqueous solutions and cast films of 1 are described. X-ray diffraction study suggests that cast films of 1 form a multilayer structure based on biomembrane-like molecular bilayers. Electron microscopy has revealed that 1 produces both fibrous and disk-like aggregates with 10-12 nm of thickness through self-organization of 1 in aqueous solution. Differential scanning calorimetry, dynamic light scattering, FTIR, and UV-visible absorption studies were also carried out to characterize aqueous solutions and cast films of 1. Electrochemistry for an aqueous solution and for cast films of just 1 and 1 incorporated in lipid films on electrodes was conducted. It was found that films of just 1 and of 1/lipid cast on electrodes showed electron transfer reactions leading to the generation of the fullerene dianion or trianion. In contrast, electrochemistry of aqueous solution of 1 at a bare electrode gives a cathodic current near -0.5 to -0.6 V against SCE; however, an anodic current for the solution did not appear.     

The reaction of 0,0-dialkyl dithiophosphoric acid—VI : Reaction of carbostyril with 0,0-dialkyl or 0,0-diphenyl dithiophosphoric acid

In the reaction between carbostyril (1 mol) and 0,0-diethyl dithiophosphoric acid (3 mol) in refluxing C₆H₆ for 130 hr 30% of thiocarbostyril and 60% of 2-ethylthioquinoline were isolated, but under the different reaction conditions the ratio of 2-ethylthioquinoline to thiocarbostyril changed. The reaction of carbostyril with 0,0-di-n-propyl or 0,0-di-i-propyl dithiophosphoric acid gave similar results with different product ratio. Meanwhile, in the reaction of carbostyril with 0,0-diphenyl dithiophosphoric acid or N-methylcarbostyril with 0,0-diethyl dithiophosphoric acid the corresponding thiocarbostyril or N-methylthiocarbostyril were obtained in good yields.     

Four-center-type photopolymerization in the crystalline state. IX. Characteristic features of topochemical process and polymer properties thus obtained

Changes in TG-DSC diagrams and X-ray diffraction patterns in the course of four-center-type photopolymerization of 2,5-distyrylpyrazine (DSP) and thermal depolymerization of poly-DSP were investigated. It has been found that as-polymerized poly-DSP crystal with high molecular weight does not melt but depolymerizes into the oligomer in the crystalline state. The crystal change found in the depolymerization was just the reverse of that in the polymerization. From the results a reversible topochemical process, which comprises monomer lattice-controlled photopolymerization and polymer lattice-controlled thermal depolymerization, has been established between DSP and poly-DSP. Quantitative thermal analysis reveals that both of the two endotherms of poly-DSP crystal include the heat of crystallization as well as that of depolymerization. Several specific properties of a topochemical product of as-polymerized poly-DSP crystal, such as nonreproducibility of the original crystal structure by recrystallization and superior stabilities to thermal depolymerization and photooxidation, are discussed in comparison with natural cellulose.     

Global stability of the rarefaction wave of a one-dimensional model system for compressible viscous gas

This paper is concerned with the asymptotic behavior toward the rarefaction wave of the solution of a one-dimensional barotropic model system for compressible viscous gas. We assume that the initial data tend to constant states atx=±, respectively, and the Riemann problem for the corresponding hyperbolic system admits a weak continuous rarefaction wave. If the adiabatic constant satisfies 12, then the solution is proved to tend to the rarefaction wave ast under no smallness conditions of both the difference of asymptotic values atx=± and the initial data. The proof is given by an elementaryL ²-energy method.     

Spectral decomposition of path space in solvable lattice model

We give thespectral decomposition of the path space of the vertex model with respect to the local energy functions. The result suggests the hidden Yangian module structure on the levell integrable modules, which is consistent with the earlier work [1] in the level one case. Also we prove the fermionic character formula of the levell integrable representations in consequence.     

Direct Obtention of Pure Compounds from Crude Plant Extracts by Preparative Liquid Chromatography

It has been possible to submit the crude hexane extract of the barks of a medicinal plant directly to preparative liquid chromatography. A two step solvent elution gave 6 peaks, four of which readily afforded crystalline material. The entire process required 2–3 hours whereas conventional chromatography required ca. 2 weeks.