The pKa of the over-all basicity of 4-aminoazobenzene and derivatives has been re solved in pKam and pK^, which represent the pKa of the two basic centers, the amino nitrogen and the /3-azo nitrogen. This resolution has made possible for the first time a comparison of the carcinogenic activity of these dyes with a property related to electron density at these centers. It appears that excessive ...

Azoheteroarene photoswitches offer functional advantages over their more conventional azobenzene counterparts by virtue of their heteroaromatic ring(s). Here we report that azobis(2-imidazole) functions as a photoswitchable base due to the additional proton stabilisation that is possible in the protonated Z isomer, facilitated by the basic imidazole nitrogens. This thermodynamic difference in s...

Desirability and good background of yogurt have led the manufacturers to use this product mostly for producing milk-based probiotic products. The aim of this study was to evalutate the effect of a mixture of prebiotics including oligofructose, lactulose, and inulin on physicochemical properties (pH value, acidity, and syneresis) of synbiotic yogurt containing lactobacillus casei. Pasteurized mi...

While pure rain is naturally slightly acidic, the higher level of acidity in acid rain makes it a threat to plant and aquatic life and to some manmade materials and structures. The slight natural acidity of pure rain is the result of carbon dioxide in the air dissolving in water to produce a weak carbonic acid solution. This natural acid in rainfall and snowmelt is partly responsible for the lo...

In this paper, the mechanism of ketone hydrogenation catalyzed by five Ru bifunctional catalysts with different structural frameworks was studied in detail using density functional theory (DFT). This mechanism contains hydrogen transfer, dehydrogenation of alcohol, and dihydrogen activation fundamental reactions. The involvement of alcohol is also discussed and found with different activities i...

Hydrothermally synthesized high silica borosilicates with the MFI structure was subjected to several characterization techniques. The effect of boron on the structure and acidity of HZSM-5 catalyst were studied by XRD, SEM, N2 adsorption, solid state NMR, NH3-TPD. It was confirmed that boron had entered the framework in the boron samples. The results also revealed that strong acidity was weaken...