Oxygenation of substituted 2′-hydroxyacetophenone 4-bromophenylhydrazones promoted by cobalt(II) schiff base complex

Substituted 2′-hydroxyacetophenone 4-bromophenylhydrazones are oxygenated readily in the presence of Co(Salpr) in ethanol to give 2-(4-bromophenylazo)-1,3-benzodioxoles in good yield. The results are rationalized in terms of the decomposition of a peroxy cobalt(III) complex intermediate by a mechanism similar to the Darkin oxidation.     

Multielement photon activation analysis of biological materials.

A non-destructive photon activation procedure with 30-MeV bremsstrahlung followed by high-resolution γ-spectrometry is proposed for multielement analysis of biological materials. The materials tested were the NBS SRM Orchard Leaves and Bovine Liver, Bowen′s kale and Kentucky 1R1 tobacco standards. Simultaneous irradiation of the sample with synthetic multielement standards containing 25 elements showed that up to 12 elements can be determined in a single sample. The method is quite simple and gives good reproducible results. Agreement of the results with published data is excellent.     

Photoconductivity of poly(N-acryloylcarbazole)

The photoconductivity of poly(N-acryloylcarbazole) (PACz), with the pendant carbazolyl group only a short distance from the skeletal chain of the polymer but separated from it by a carbonyl group, is investigated and compared with that of poly(N-vinylcarbazole) (PVCz). There is no significant difference between PACz and PVCz in the temperature, light intensity, and spectral dependences of the photocurrent. The photoconductivity of PACz, however, is much inferior to that of PVCz and even to that of poly(N-carbazolylethylvinylether), a representative vinyl polymer with pendant carbazolyl groups far from the skeletal chain. The poor photoconductivity of PACz is discussed in relation to the intensity of the electronic interaction between neighboring carbazolyl groups in the polymer chain and to singlet exciton migration. It is attributed mainly to an extremely low efficiency of extrinsic carrier generation via a singlet exciton, which is due to the poor electron-donating character and the extremely short lifetime of a singlet exciton in the presence of the carbonyl group.     

FEM study of NOW and NO2W adsorption system

Nitric oxide adsorption on tungsten and nitric dioxide adsorption on tungsten have been investigated by the FEM method. When NO or NO₂ adsorbs gradually on W at 300 K and at 80 K, the FEM patterns which appear at first are found to be similar to those which appear in N₂ adsorption on W. In the case of NO adsorption on W at 80 K, with further exposure, no further change of the FEM patterns is observed. However, in the cases of NO adsorption on W at 300 K, NO₂ adsorption on W at 300 K, and NO₂ adsorption on W at 80 K, further changes of the FEM patterns are observed with further exposure, and the FEM pattern which is obtained at the saturated state is found to be similar to the FEM pattern which appears at the saturated state of O₂ adsorption on W. From the above results it is suggested that NO and NO₂ dissociate on W at 300 and at 80 K.