Chitosan membrane exhibited a good visible light photocatalytic activity over tetracycline hydrochloride degradation. The corresponding degradation mechanism was investigated as shown above.
Many mass-transfer applications have used chitosan membrane in separation processes. This research applied crosslinked chitosan membrane to sterillize bacterial growth media. Chitosan membranes having 79 % DD were produced by casting and drying chitosan solution. The images of the membrane were characterized by SEM and other characterizations such as permeability, permselectivity and tensile strength were investigated. The flux increased with longer submersion period but the rejection decreased. Otherwise, the flux decreased and rejection increased in line with an increase in curing temperature. Tensile strength increased with the increase of submersion period and curing temperature. The optimum conditions of crosslinking process are 2 hours of submersion periods and curing temperature at 90 oC. It gives flux 5.8930 L/jam.m2, rejection 97.47 % and tensile strength 49640 kN/m2
Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.
<p>Herein we
report a sulfur (IV) mediated cross-coupling for facile synthesis of heteroaromatic
substrates. Addition of heteroaryl nucleophiles onto a simple,
readily-accessible alkyl sulfinyl (IV) chloride allows formation of a trigonal
bipyramidal sulfurane intermediate. Reductive elimination therefrom provides bis-heteroaryl
products in a practical and efficient fashion. <br></p>
We have described simple, high-yield, protocols, which require only commonly accessible equipment, to synthesize a wide range of β-CD derivatives mono-substituted at the secondary face. These derivatives may be useful in their own right, and they are also scaffolds for further modification, and examples of the far broader array of derivatives that may be accessed by these procedures.