Oxidation

The unique properties associated with these dendrimers such as uniform size, high degree of branching, water solubility, multivalency, well-defined molecular weight and available internal cavities make them attractive for biological and drug-delivery applications. Commercialization of dendrimers is now forthcoming. A new dendrimeric ligand (L) was synthesized by the Michael addition of ethylenediamine to methyl methacrylate. The prepared ligand was complexed Cu (II) ions, the ligand and its complex were characterized by elemental analysis and spectroscopic studies (FT-IR, UV-Vis, 1H NMR and ESI-MS). Square pyramidal geometry was proposed for copper complexes, on the basis of UV-Vis spectroscopic data and molar conductance measurements. The dendrimer metal complex is active towards the oxidation of alcoholic substrates using molecular oxygen as substrate. The effect of various parameters on the rate of reaction is also explained.

Catalysis is an area of research which still continues to be a premier area of chemistry. It plays a key role in modern chemical technology. There are a large number of important organic transformations such as oxidation, hydrogenation, hydroformylation, carbonylation, polymerization and various coupling reactions. The majority of these novel catalysts are based on silica, primarily since silica displays many advantageous properties excellent stability (chemical and thermal), high surface area, good accessibility, and organic groups can be robustly anchored to the surface, to provide catalytic centers. However, it does have drawbacks it has limited stability in aqueous especially basic conditions, and it cannot easily be formed into membranes or into other forms which could be attached to novel reactors for use in intensive processing applications.

A novel complex of quadridentate ligand modified chitosan was synthesized by sequential attachment of Isatin (1H-indole-2, 3-Dione) copper chloride dehydrate to chitosan. Synthesized catalyst was characterized by different techniques like FTIR, ESI-MS, and Powder X-ray diffraction method. The biological activity was done using diffusion disc technique. It was found that the complex shows excellent activity towards fungi and bacteria. The catalytic activity of this catalyst was tested for the oxidation of 2-butanol by varying the temperature of system as well as concentration of substrate and catalyst. Values of activation energy have been evaluated from the kinetic data.

Four simple, accurate and highly sensitive spectrophotometric methods have been developed for the determination of Lansoprazole in both pure and in pharmaceutical preparations. The method A andB  are based on the ion associationcomplex formation between Lansoprazole and Supracen Violet 3B (method A) or Tropaeolin OOO (method B)  the third and fourth are indirect methods where the drug is oxidsed by a known excess of Chloramine T and determining the consumed Chloramine T with decrease in colour intensity of the dye Gallocyanine (method C ) or oxidation with excess of N-Bromosuccunimide in acid medium. followed by the determination of unreacted N-Bromosuccunimide with the dye Celestin Blue - (method D) .Regreesion analysis of Beer’s law plots showed good correlation in the concentration range of  5.0 - 40 μg ml−1, 5.0 -25 μg ml−1 , 2.5 – 12.5 μg ml−1, 1.0 – 6.0μg ml−1 for methods A, B ,C and D respectively, and the corresponding molar absorptivity values are 0.9232 x 104 , 1.0857 x 104 , 7.0997 x 104 and 2.3265 x 104 1mol−1cm−1. All variables have been optimized and the results were statistically compared with those of literature methods by employing the student’s t-test and F-test. No interference was observed from excipients normally added to the tablets.