Molecular orbital calculations on copper chloride complexes

The M.O. calcn. is of the Wolfsberg-Helmholtz type. However, in contrast to the usual empirical detn. of the H11 integrals, these integrals are computed from the wave functions of the free ions. The calcn. is performed on Cu in a tetrahedral, sq. planar and octahedral environment of Cl, the results being compared subsequently. [on SciFinder (R)

Bismuth molybdate catalysts : Preparation, characterization and activity of different compounds in the Bi---Mo---O system

The influence on oxidation activity of the method of preparation of Bi---Mo catalysts and in particular the circumstances during the wet stage (precipitation, slurry reactions between preprecipitated oxyhydrates) have been investigated. It was found that active Bi/Mo = 2/1 catalysts have to be prepared by a slurry reaction starting from what is essentially (BiO) (NO3). Even the application of powdered crystals of compounds with this composition leads to active catalysts. Contrary to previous work, active 1/1 catalysts can only be prepared by precipitation but the phase formed is not stable against prolonged heating at temperatures around 500 °C

Sulfided Supported Tungsten and Molybdenum Catalysts Promoted by Nickel or Cobalt. An ESR Study

The ESR signals related with the sulfide phase present in W(Mo)/SiO2(y-Al2O3) are found to disappear as reasult of nickel or cobalt introduction. Consequently Ni(Co)-W(Mo)/SiO2(y-Al2O3) catalysts showed less complex ESR spectra in wich only two different ESR signals could be analyzed. This 'promotor' effect is discussed in terms of surface reorganization due to the incorporation od NI2+(Co2+)ions in the WS2(MoS2)phase. Absorption of carbonmonoxide is found to affect the ESR spectra of W/SiO2 and Ni-W/SiO2 in different ways, indicating that nickel influences the absorptive and electronic properties of the catalyst. The effects of CO absorption can be explained by means of electron transfer from CO to the catalyst