Fabrication of Small Fluorescence Scale Patterns by Electron Beam Drawing Using Polymer Film Containing Fluorescence Dye

We report the fabrication of a resolution–evaluation chart and a scale for a fluorescence microscope. Small fluorescence patterns were fabricated by irradiating an electron beam (EB) in a thin film prepared by dispersing fluorescence dye (rhodamine 590) in poly(methyl methacrylate) (PMMA) and by development to remove EB-irradiated parts. As a result, the fluorescence emission pattern of nanometer order (a line width of 110 nm and a line interval of 370 nm) with sufficient fluorescence intensity was obtained, and a 1 μm bright fluorescence scale for the laser scanning fluorescence microscope was fabricated. These fluorescence patterns are handled easily and are effective for measurement using a fluorescence microscope.     

Influence of AgCl precipitates on the precipitation titration of sodium chloride by constant-current coulometry.

The precipitation titration of sodium chloride with electrogenerated silver ion was studied. The production of a precipitate of silver chloride had a significant effect on the titration results because the precipitate involved unreacted chloride or unreacted silver ion. The accuracy of the method was investigated by changing the introduction time of a sodium chloride solution to the coulometric cell during the process of electrolysis, and examining the dependency on the sample size. The accuracy of the measurement of the precipitation titration is discussed.     

Photosensitized cyclodimerizations of 4-vinylpyridine, 2-vinylpyridine,and 2-vinylquinoline

Irradiations of 4-vinylpyridine and of 2-vinylpyridine in either f-butyl alcohol or benzene, with benzophenone, yielded a single photodimer, which, on the basis of the nmr and mass spectral data, was assigned the trans-head-to-head structure (I). Upon irradiation in either t-butyl alcohol or benzene, in the presence of benzophenone, 2-vinylquinoline gave a single photodimer whose structure and stereochemistry were also determined from the nmr and mass spectral evidence as (V). Irradiation of 2-vinylquinoline in benzene, in the absence of benzophenone, also gave rise to the same photodimer, but, when t-butyl alcohol or methanol was used as a solvent, no dimer formation was observed.     

Bimolecular reaction via the successive introduction of two substrates into the crystals of networked molecular cages

Two substrates, 4-hydroxydiphenylamine (3) and ethyl isocyanate (4), were successively introduced into the crystals of networked M(6)L(4) cages 1. Because of the encapsulation effect, most of the initially introduced substrate 3 remained within the crystals during immersion in a solution of 4. X-ray analysis revealed that before the reaction, the nucleophilic NH group of 3 is effectively protected by tight packing within the cage units while the OH group is exposed to the incoming second substrate. Successive introduction of 4 into the crystal results in the chemoselective acylation of 3 at the less nucleophilic OH group. The observed chemoselectivity is consistent with that exhibited by discrete M(6)L(4) cage 2 in solution.     

Preparation of La2O3-TiO2-SiO2 Inorganic-Organic Hybrid Materials and Their Optical Properties

Inorganic-organic hybrid materials in La₂O₃-TiO₂-SiO₂ system were prepared from La(NO₃)₃, titanium tetraisopropoxide, and silicon alkoxides. Ternary transparent materials prepared from glycidyloxypropyltrimethoxysilane (GPTS) were obtained in a wide composition region (La₂O₃ 50 mol%, TiO₂ 40 mol%). Hybrid materials prepared using methyltrimethoxysilane (MTMS) at MTMS/TMOS = 1 were transparent in the composition of La₂O₃ 30 mol% and TiO₂ 25 mol%. La(NO₃)₃ crystallines or TiO₂ small particles were precipitated in translucent materials. La₂O₃ content strongly affected the bulk density compared with TiO₂ content. Absorption edge of the hybrid materials was shifted to longer wavelength as TiO₂ and La₂O₃ contents increased. Partial coefficient of refractive index for the three metal oxides increased in the order SiO₂ < TiO₂ < La₂O₃ for both hybrid materials.     

Syntheses of AM-toxin III and its analogs using the Hofmann degradation

Syntheses of cyclotetradepsipeptides, AM-toxin III and two analogs, were achieved, in which the Hofmann degradation method was used in order to derive a dehydroalanine residue from a 2,3-diaminopropionic acid residue in cyclodepsipeptide precursors.     

Selective chemisorption of end-functionalized conjugated polymer on macro- and nanoscale surfaces

Linear and conjugated poly(p-phenylene ethynylene)s (PPEs) with three different types of functionalized end groups (thiolacetate, isocyanide, and carboxylic acid groups) were synthesized, and their selective chemisorption behavior on various substrate surfaces were investigated using UV/vis transmission absorption spectroscopy. The UV/vis spectra of the PPEs were clearly dependent on the chemical affinity between the PPE end group and the solid surfaces. Furthermore, regarding the chemisorption of thiolacetate modified polymer on a nanoscopic gold particle surface, we visualized novel polymer-colloid nanoarchitectures such as a barbell-type nanohybrid and interconnected polymer nanowire structures that are successively linked through gold nanoparticles.