Phosphorescence of 8-azasteroids and related compounds.
We have investigated the electron absorption, fluorescence and phosphorescence spectra of 8-azasteroids and model compounds containing enaminodicarbonyl fragment. It has been shown that the investigated compounds have absorption and phosphorescence spectra similar in form and position. The results obtained permit the conclusion that the main deactivation channel of the excited singlet state is the intersystem crossing. It is suggested that the investigated 8-azasteroids of enaminodicarbonyl series under light irradiation undergo phototransformations presumably into derivatives with a gamma-pyridone fragment.
Estimation of ecdysterone from sulfuric acid induced fluorescence.
Abstract The sulfuric acid induction of ecdysterone (2 β ,3 β ,14 α ,20R,22R,25-hexahydroxy-5 β -cholest-7-en-6-one) fluorescence was examined under various conditions of acid concentrations, acid diluents, reaction duration and reaction temperature. With appropriate conditions ecdysterone standards could be estimated in amounts from ca. 5 ng to in excess of 10 μ g. The similarity of the fluorescence spectra and yields of some other ecdysteroids suggested that the method is applicable to other compounds of this type.
The Chemistry of the Semiconductor Industry
Overview. Semiconductor silicon. Group III-V compounds. Group II-VI semiconductors. Chemical vapour deposition. Plasma-enhanced chemical vapour deposition. Metal-organic vapour phase epitaxy. Liquid-phase epitaxy of III-V compounds. Photoresists. X-ray and E-beam resists. Wet etching. Polyimides. Molecular electronics. Computer modelling. Plasma etching. Polymers in plasmas.