A novel aromatic alkylation of anilines with cyclic and acyclic ketones under hydrothermal conditions

A novel aromatic ring-alkylation was achieved by condensation between aniline·HCl salts and cyclic or acyclic ketones under hydrothermal conditions.     

Dodecylsulfate-coated monolithic octadecyl-bonded silica stationary phase for high-speed separation of hydrogen, magnesium and calcium in rainwater

The high-speed determination of hydrogen, magnesium and calcium ions by ion chromatography (IC) is demonstrated on a monolithic octadecyl-boned silica (ODS) column coated with lithium dodecylsulfate (Li-DS). This stationary phase, when used in conjunction with a 2 mM ethylenediamine and 0.1 mM Li-DS solution as eluent at pH 6.0, was found to be suitable for the rapid and efficient separation of hydrogen and magnesium and calcium in the order H+ < Mg2+ < Ca2+ within 4 min at a flow rate of 4.0 ml/min. Under the conditions, linear calibration plots of conductivity versus concentration were obtained for the cations over about three orders of magnitude, and the detection limits were 1 microM for H+, 2 microM for Mg2+ and Ca2+. Rainwater was analyzed directly using this IC system with satisfactory results.     

Analysis of guest—host and intra-guest transitions for hydronaphthyl radicals in naphthalene crystals

High resolution spectroscopic studies of optical absorption and emission around 539 nm and 636 nm for 1- and 2-hydronaphthyl radicals in naphthalene crystals have been made. For each radical several lines with the same polarization as the intra-guest OO vibrational lines were assigned as the vibrational progression, the separation being explained in terms of the intramolecular vibrations of naphthalene. About 20 other lines for each radical, including completely a- or b-polarized lines, were ascribed to the guest—host charge transfer transitions. Each line was assigned to the transition to specific molecules around the radical taking the polarization into consideration. The energy of the transition to a molecule at a distance r can be described by a coulombic relation with the dielectric constant ?: E = E_∞ ?e²/?r, where E_∞ is a constant. The phonon sidebands of the absorption and emission lines of the most intense charge transfer transition in the 1-hydronaphthyl radical was also analyzed and compared with phonon singularities in naphthalene crystals.     

Probing Electron Transfer in DNA – New Life Science with Muons

Using the method of labelled electrons with muons which was first applied to conducting polymers and recently extended to representative electron-transfer proteins, electron transfer phenomena in DNA were successfully studied, for the first time microscopically. The characteristic dependence of muon spin relaxation on inverse magnetic field between 80 and 4000 G strongly suggests an existence of topological one-dimensional (1D) electron transfer along the DNA strands in both A- and B-forms. The low-field behavior, on the other hand, showed remarkable dependence on the molecular conformations. This revised version was published online in August 2006 with corrections to the Cover Date.     

Radiation-induced chemical evolution of biomolecules

Chemical evolution in glycilglycine (Gly2) films irradiated with 146 nm vacuum ultraviolet light was studied. It is found that quantum efficiency of chemical evolution from Gly2 to glycilglycilglycine (Gly3) is smaller than that to glycilglycilglycilglycine (Gly4) due to the multiple step of reaction. Furthermore, we have carried out measurement of soft X-ray natural circular dichroism spectra for serine and alanine films in the energy region of oxygen 1s transition and we report the splitting of 1s→π* transitions.     

First observation of natural circular dichroism spectra in the extreme ultraviolet region using a polarizing undulator‐based optical system and its polarization characteristics

Natural circular dichroism (CD) spectra in the extreme ultraviolet (EUV) region down to a wavelength of 80 nm have been observed for the first time, using an alanine thin film deposited on sodium salicylate coated glass as a sample. Calibrated EUV‐CD spectra of l ‐alanine exhibited a large negative peak at around 120 nm and a positive CD signal below 90 nm, which were roughly predicted by theoretical calculations. A CD measurement system with an Onuki‐type polarizing undulator was used to obtain the EUV‐CD spectra. This CD system, the development of which took five years, can be used to observe even weak natural CD spectra. The polarization characteristics of this system were also evaluated in order to calibrate the recorded CD spectra.     

Retrieving angular distributions of high-order harmonic generation from a single molecule

We present a novel method to retrieve angular distributions of high-order harmonic generation from a single molecule. This technique uses an iterative procedure based only on experimental results of time and angle-dependent harmonic signals, and no actual shape of molecular orbital is assumed. The molecular axis distribution in a target gas can simultaneously be deduced in this procedure. The angle-dependent signal retrieved for a single N2 and O2 molecule is demonstrated to reflect the highest occupied molecular orbital, excluding the ambiguity due to the imperfect alignment.     

Hydrothermal crystallisation of anatase and characterisation of photocatalytic properties

Abstract

Hydrothermal processing has been used to prepare anatase powders from amorphous titania, for use as photocatalysts. There is a change in crystallisation mechanism from solid state to dissolution/precipitation at around 250°C, which has been shown to result in the removal of the brookite secondary product which normally occurs at lower temperatures. The use of a slightly basic solution has also been shown to eliminate brookite production. Photocatalysis experiments have shown that the hydrothermally produced powders have a high activity when compared to the commercial powder Degussa P25. The presence of the brookite phase in some samples reduces the activity.