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Hideyuki Nishizawa

Publications and source records attributed to Hideyuki Nishizawa.

2 recordsLinked to original sources
PubMed2003

Improved apparatus for solid-liquid multi-stage counter-current extraction.

An improved apparatus for solid-liquid multi-stage counter-current extraction (SLME) was developed. The apparatus has a set of 24 extraction vessels. Each extraction vessel unit is composed of a piston-cylinder in which the solid phase is placed, and a cup-cylinder in which the liquid phase is set. Of the 24 extraction vessels, 20 were used for the separation stage, and the other 4 were used for the back-extraction stage. (+/-)-Troger's base was selected as a racemic model compound for the continuous enantioseparation by the apparatus, and a cellulose derivative was used as the chiral separator. After 50 cycles of the operation (in 9 h), 0.1 g of (-)-enantiomer (85% in purity) was recovered from the solid phase by back-extraction with ethanol, whereas 1.1 g of (+)-isomer (75% in purity) was collected from the liquid phase (ethanol).

Chromatography, High Pressure Liquid↗
PubMed2003

Photoinduced electron transfer and electron-mediating systems from aromatic amines to triplet states of C60 and C70 in the presence of a viologen dication.

Photoinduced electron transfer between fullerenes (C60 and C70) and various aromatic amines (AA's) in the absence and presence of a viologen dication has been studied by the transient absorption method in the visible and near-IR regions. Electron-transfer takes place from AA's to the triplet states of fullerenes (3C60* and 3C70*) giving the anion radicals of fullerenes (C60*- and C70*-) and the radical cations of AA's (AA*+). The rate constants and efficiencies of electron transfer are quite high, because of the high electron-donor abilities of AA's as their low oxidation potentials indicate. The absorption bands of AA*+ appeared also in the near-IR region indicating that the radical-cation center (hole) delocalizes over the entire region of each AA. On addition of an octylviologen dication (OV2+) to C60/C70-AA systems, the electron-mediating process from C60*- and C70*- to OV2+ occurs yielding the viologen radical cation (OV*+) with longer lifetime.

Journal Article↗