PHOTOINDUCED CATALYTIC DECOMPOSITION OF PYRUVIC ACID

Abstract— Electronic and catalytic properties of CuO doped by univalent or trivalent elements were investigated. Doping B or Sb into CuO was found to induce the decarboxylation reaction of pyruvic acid under irradiation with visible light. The decarboxylation reaction is accelerated by raising the temperature. The electronic conductivity of CuO is decreased by increasing the doping concentration of the trivalent element in the low concentration region and increased in the high concentration region. The doping concentration which gives the maximum production of the catalytic decarboxylation is well coincident with the concentration at the minimum electronic conductivity.     

Correlation between hydrophobic attraction and the free energy of hydrophobic hydration

We correlate the strength of the solvent-mediated attraction of a pair of hydrophobic solute molecules with the free energy of hydration of a single such molecule. This is done in the framework of a particular model but the results may be more general. When the model parameters are chosen to represent methane as the solute in water it is found that over the relevant temperature range the strength of the attraction, expressed as a multiple of the thermal energy kT, increases nearly linearly with increasing hydration free energy expressed in the same units. In the middle of the temperature range studied the strength of the attraction is roughly one-third of the hydration free energy.     

Preparation of water-soluble sodium deoxycellulosesulfonate from homogeneously prepared tosylcellulose

Water-soluble sodium deoxycellulosesulfonate (DCS-Na) was prepared by nucleophilic substitution of the p-toluenesulfonyl (tosyl) groups of cellulose p-toluenesulfonate (tosylcellulose) by a sulfonate group in aqueous Na2SO3 solution. In the substitution, the yield and degree of substitution (DS) by the sulfonate group (DSsul) were found to increase with increasing reaction temperature and with reaction time, and reached up to 80% and 0.28, respectively, at 100 °C for 72 h. Although the DS of the tosyl group (DStosyl) decreased with increasing reaction temperature and with reaction time, a respectable amount of tosyl group still remained even at 100 °C for 72 h. Furthermore, the intrinsic viscosity, [], of the DCS-Na obtained decreased considerably with increasing reaction temperature and with reaction time. The decreases in DStosyl and [] were very similar to each other in that increasing DSsul was independent of the reaction temperature and the reaction time. The similarity of the decreases suggests that the mechanisms of scission of the cellulose backbone and the leaving of the tosyl groups (from tosylcellulose) in the nucleophilic substitution were closely related to each other. The partial conversion of the tosyl group in the tosylcellulose to the sulfonate group, by the nucleophilic substitution, was also confirmed by the change in the IR absorption spectrum. The product could be considered to be a ter-polymer from the point of view of the AGU (anhydro glucose unit). Thus, we have AGU-co-DAGUS-Na-tosyl AGU as possible options