Calorimetric study of the cubic mesogen,ACBC(16)

The heat capacity of the cubic mesogen ACBC(16) was measured between 16 and 500?K by adiabatic calorimetry. As well as the known condensed phases, a new crystalline phase was found to undergo a glass transition at around 165?K. Phase transitions between crystal, SmC, cubic, and isotropic liquid phases took place at 399.16, 431.15, and 474.30?K, respectively. As in the case of ANBC, a broad hump was observed in the heat capacity of the isotropic liquid phase. The first order nature of the SmC–cubic phase transition was confirmed for the first time by the observation of supercooling of the cubic phase. The broad hump in the isotropic liquid phase was shown to extend to a low temperature side if the isotropic liquid was supercooled, suggesting that the event occurring at the hump is not directly related to the cubic–isotropic liquid phase transition.     

Mode-selective excitation of coherent surface phonons on alkali-covered metal surfaces

We demonstrate the mode-selective excitation of coherent phonons at Pt(111) surfaces covered with submonolayer caesium atoms. A burst of 150 fs laser pulses with the repetition rate of 2.0-2.9 THz was synthesized by using a spatial-light modulator, and used for the coherent surface phonon excitation. The coherent nuclear motion was monitored by time-resolved second harmonic generation. By tuning the repetition rate, we succeeded in controlling the relative amplitude of the vibrational coherence of the Cs-Pt stretching mode (2.3-2.4 THz) to that of the Pt surface Rayleigh phonon mode (2.6 or 2.9 THz, depending on the Cs coverage).     

Stereocontrolled synthesis of either (22S)- or (22R)-hydroxy-23-acetylenic steroid side chains via [2,3]-Wittig sigmatropic rearrangement

A unified approach to either (22$\text{S}$)- or (22$\text{R}$)-hydroxy-23-acetylenic steroid side chains is described which relies on the concept of the stereochemical transmission via the [2,3]-Wittig sigmatropic rearrangement.     

Comparison of thermal degradation products from real municipal waste plastic and model mixed plastics

The thermal degradation of real municipal waste plastic (MWP) obtained from Sapporo, Japan and model mixed plastics was carried out at 430 °C in atmospheric pressure by batch operation. The chlorinated hydrocarbons found in PE/PP/PS/PVC [poly(ethylene)/poly(propylene)/poly(styrene)/poly(vinyl chloride)] degradation liquid products were also observed in PE/PP/PS/PVC/PET (poly(ethylene terephalate)) and MWP degradation liquid products. The presence of PET in MWP produced the additional chlorinated hydrocarbons, which are similar to the chlorinated hydrocarbons observed during the PE/PP/PS/PVC/PET degradation liquid products. In addition, the presence of PET facilitated the formation of more organic chlorine content in liquid products and drastic decrease in the formation of inorganic chlorine content.     

Sensing capabilities of colloidal gold modified with a self-assembled monolayer of a glucose-carrying polymer chain on a glass substrate

A disulfide-carrying polymer with pendent glucose residues (poly(2-methacryloyloxyethyl D-glucopyranoside)) was obtained by using a benzyl N,N-diethyldithiocarbamoyl derivative which shows the abilities of initiation, chain transfer, and termination (iniferter). The disulfide-carrying polymer was accumulated on a colloidal Au-immobilized glass substrate, and the usefulness of the polymer as a sensing element of concanavalin A (Con A) was examined by using a UV-visible spectrophotometer with the help of surface plasmon resonance. The sensor showed a concentration-dependent specific binding of Con A with a detection limit of 1.9 nM, and furthermore, it had a very high stability at high ionic strength. The polymer-coated device examined here was not only useful as a simple biosensor chip but is also expected to expand our knowledge of interfacial phenomena by introducing various functional polymers on colloidal Au.     

Nickel-catalyzed regioselective synthesis of tetrasubstituted alkene using alkylative carboxylation of disubstituted alkyne

[Reaction: see text] Syntheses of alpha-silyl-beta,beta'-dialkyl alpha,beta-unsaturated carboxylic acids were achieved from silylated alkyne, carbon dioxide, and a zinc reagent using a catalytic amount of nickel complex in the presence of an excess amount of DBU. The regioselectivity of the introduction of CO2 into disubstituted alkyne is dependent on the electronic property of the substituent R on the alkyne because the thermodynamic stability of oxanickelacycle IV or V should be affected by conjugation of the substituent R with the carboxyl group in IV or V.