Experimental study of water-ice catalyzed thermal isomerization of cyanamide into carbodiimide: implication for prebiotic chemistry.

CATALYTIC REFORMING OF n-HEPTANE ON PLATINUM-TUNGSTEN SUPPORTED ON GAMMA-ALUMINA

The mono-metallic and bi-metallic catalysts have been prepared by impregnating with solutions containing a compound of H2PtCl6,WO3 and 1ml HCl (0.1 mol). It should be noted that the catalysts’ activity and selectivity have been determined under these conditions : 450-5000C ,and 15-25atm by H2. For converting n-heptane , the molar ratio H2/C7H16 is 5 , and LHSV is 1.5ml/h. It has been proved tha...

Base Catalyzed Cyclization and Isomerization of 3-Propargylmercapto-1, 2,4-Triazine to Thiazolo [3,2-b][1,2,4]-Triazines

Transformation of 3-propargylmercapto-6 methyl-1, 2,4-triazin- 5 (2H)- one (1; R=CH3) to 3,6- dimethyl-7H- thiazolo [3,2-b] [1, 2, 4] triazin -7- one (2) is performed under basic condition. The formation of (2) may be mainly due to the high reactivity of acetylenes towards nucleophiles and isomerization of the intermediate. 

Thermal regeneration and decoking optimization of chlorinated platinum/alumina catalysts for the isomerization process

The samples of spent chlorinated Pt/Al2O3 catalysts that were used in the isomerization process were decoked at elevated temperatures under airflow and different oxygen concentrations. The surface of the catalyst was characterized by thermal gravimetric analysis, differential scanning calorimetry, Brunauer-Emmett-Teller analysis, attenuated total reflection fast Fourier in...

alkali-catalyzed isomerization of lactose lactulose: study of reaction parameters and purification method

Thermal properties of rhodopsin: insight into the molecular mechanism of dim-light vision.

Rhodopsin has developed mechanisms to optimize its sensitivity to light by suppressing dark noise and enhancing quantum yield. We propose that an intramolecular hydrogen-bonding network formed by ∼20 water molecules, the hydrophilic residues, and peptide backbones in the transmembrane region is essential to restrain thermal isomerization, the source of dark noise. We studied the thermal stabili...