Reductive Ring‐Opening Reaction of 2,3‐Epoxy‐1,4‐butanediones with SbCl3‐Bu4NI in the Presence of Na2S2O3·5H2O

1,4‐Disubstituted 2,3‐epoxy‐1,4‐butanediones were converted to 1,4‐disubstituted 2‐hydroxy‐1,4‐butanediones with SbCl₃‐Bu₄NI in the presence of Na₂S₂O₃ · 5H₂O. The ring opening of terminal epoxides can also be accomplished to afford the corresponding haloalcohol with SbCl₃ and tetrabutylammonium halides, Bu₄NX (X=Cl, Br, I) under the same reaction conditions.     

Far-infrared spectroscopy by synchrotron radiation at the UVSOR Facility

At the UVSOR Facility, Institute for Molecular Science, the practical use of the synchrotron radiation as a far-infrared light source has started. A spectroscopic system has been constructed at the beam line BL6A1 of UVSOR storage ring, which covers the wavenumber region from 5 to 250 cm^–1. The cross sectional diameter of the light beam at the sample position is as small as 3 mm with the angular divergence of about 100 mrad. The system has been made mainly for the transmission and reflection measurements of small samples with small angular divergence by the use of the high brightness of the synchrotron radiation. Examples of observed transmission and reflectivity spectra are shown.     

Amplitude Statistics of Sea-Ice Clutter Using a Millimeter Wave Radar

Sea-ice clutter was measured using a millimeter wave radar with frequency of 34.86GHz and pulse length of 30ns. To determine the sea-ice clutter amplitude statistics, we investigated the log-normal, Weibull, log-Weibull and K-distributions using the Akaike Information Criterion (AIC), which is more rigorous fit of the distribution to the data than the least-squares method. It is shown that the amplitude of sea-ice clutter obeys almost a log-Weibull distribution.     

Novel High Precision Optoelectronic Device Fabrication Technique Using Guided Fluidic Assembly

High precision assembly of laser diodes (LDs) on silicon wafer substrates for use in advanced optoelectronic devices is an important issue from a mass production point of view. An acceptable alternative to replace an obsolete pick and place flip chip bonding robotic technology with a simple, low cost and high speed technique is desired for industrial applications. We have investigated a novel assembling technique with micrometer order accuracy for LDs and other microchips. Its feasibility for rapidly assembling a large number of high power edge emitting LDs is practically demonstrated. A 150 $mUm thick nickel metal mask is used to confine as well as guide the unassembled LDs into the recesses by its restricted displacements. This technique is based on guiding the LDs within a suitable fluidic medium and the assembling process is performed in two steps: (i) coarse precision with a confinement mask to bring LDs near the recesses to achieve high assembling efficiency and (ii) fine precision due to the electrode patterns on the base surface of LDs, under fluidic as well as gravitational force. The assembly of 80 red LDs of the same size and of 40 pairs of red and infrared LDs of two different sizes is successfully demonstrated within less than ±2 $mUm precision and 100% efficiency in a few seconds after transferring them into a confinement mask region.     

Effect of electric fields on the surface profiles of electrorheological suspensions

The surface deformation induced in electric fields is studied on the comb pattern electrodes for silica suspensions. On the application of electric fields, a fine pattern with a waveform is developed from the smooth surface. The surface profiles can be approximated by single sinusoidal waves or their superposition depending on the sample thickness. In electric fields, the silica suspensions shows the viscosity decrease in steady shear and yield stress in the limit of zero shear rates. The viscosity decrease can be attributed to electrophoretic migration of particles to one electrode and the development of yield stress to eletrorheological effects due to chain formation of particles between electrodes. In thick liquid films, the dielectric polarization forces are predominant and the sinusoidal profiles with a wavelength of pitch of electrodes are formed. In thin films, the electrophoretic forces are predominant and the wavelength coincides with twice the pitch of electrodes. At intermediate thicknesses, the surface profiles can be expressed by a superposition of two sinusoidal waves.     

High-resolution characterization of liquid-crystalline [60]fullerenes using solid-state nuclear magnetic resonance spectroscopy

Liquid-crystalline materials containing fullerenes are valuable in the development of supramolecular switches and in solar cell technology. In this study, we characterize the liquid-crystalline and dynamic properties of fullerene-containing thermotropic compounds using solid-state natural abundance (13)C NMR experiments under stationary and magic angle spinning sample conditions. Chemical shifts spectra were measured in isotropic, liquid-crystalline nematic and smectic A and crystalline phases using one-dimensional (13)C experiments, while two-dimensional separated local-field experiments were used to measure the (1)H- (13)C dipolar couplings in mesophases. Chemical shift and dipolar coupling parameters were used to characterize the structure and dynamics of the liquid-crystalline dyads. NMR data of fullerene-containing thermotropic liquid crystals are compared to that of basic mesogenic unit and mesomorphic promoter compounds. Our NMR results suggest that the fullerene-ferrocene dyads form highly dynamic liquid-crystalline phases in which molecules rotate fast around the symmetry axis on the characteristic NMR time scale of approximately 10 (-4) s.     

A practical route for synthesizing a PET ligand containing [F]fluorobenzene using reaction of diphenyliodonium salt with [F]F

The aim of this study was to develop a practical route for preparing a fluorine-18 ([¹⁸F]) labelled ligand ([¹⁸F]1) containing [¹⁸F]fluorobenzene ring by employing the reaction of diphenyliodonium salt with [¹⁸F]F⁻. Diphenyliodonium tosylate (2) was synthesized from tributylphenylstannyl compound (6) with [hydroxy(tosyloxy)iodo]benzene (7). Using this method, [¹⁸F]DAA1106 ([¹⁸F]3a), a positron emission tomography ligand for imaging peripheral-type benzodiazepine receptor, was prepared.     

Ni(0)-promoted hydroxycarboxylation of 1,2-dienes by reaction with CO2 and O2

[structure: see text]. A novel method for the preparation of hydroxy carboxylic acid derivatives has been developed by O2-oxidation of pi-allylnickel intermediates generated by Ni(0)-mediated coupling of 1,2-dienes with CO2.     

Development of a scanning microscopy by total internal reflection coupled with thermal lens spectroscopy

Non-destructive measurement of a small region on a solid/liquid interface is of great importance in physical chemistry and biochemistry, especially in the research of thin films and cell membranes. Optical methods for surface analysis with high lateral resolution are suitable methods for monitoring them. We now report a new scanning optical microscopic method to which total internal reflection coupled with a thermal lens technique was introduced. Its lateral resolution was estimated both experimentally and theoretically. To experimentally estimate the resolution, the grid patterns of thin photoresist films with well-defined lateral structures were measured. The experimental resolution was about 45 microm, which was almost same as the diameter of the excitation beam at a glass/sample interface. From this result, it was verified that this new scanning microscopy ideally worked.