Kinetic studies on cobalt-borate catalysed decomposition of hydrogen peroxide

795-797Borax promotes cobalt(II) acetate catalysed decomposition of hydrogen peroxide. The rate constants are of the order 0.155-2.17x 10-3min-1  at 29°C. A cobalt borate catalyst, prepared by anion exchange reaction of cobalt(II) acetate with borax, can independently decompose hydrogen peroxide. Th"iscatalyst along with borax, decomposes hydrogen peroxide with a first order rate constant of 0.86x 10-3 min-1 at 29°C. The rate of decomposition of hydrogen peroxide in the presence of cobalt borate catalyst increases on addition of supporting substrates such as alumina and silica. However, triphenylphosphine decreases the rate of cobalt catalysed decomposition of hydrogen peroxide

Investigation on bindings of a binaphthoquinone derivative with serum albumin proteins by fluorescence spectroscopy

824-829Binding of a binaphthoquinone derivative namely, 5a,5b-dimethyldibenzo[b,h]biphenylene-5,6,11,12(5aH,5bH,11aH,11bH)-tetraone (L, C22H16O4) with bovine serum albumin (BSA) and human serum albumin (HSA) have been examined by using fluorescence spectroscopy. The fluorescence emission of the L is quenched upon addition of L to a solution of BSA or that of HSA, but the BSA has shown a higher affinity towards L over the HSA protein. A molecular docking study is also performed to suggest the sites of BSA for weak interactions to bind the L. The docking analysis, has revealed the N-H•••O hydrogen bonds of L with different amino acid residues. The L is located at about 7.7Å away from the Trp-213 which is the fluorescent unit of the BSA suggesting the role of environment of the tryptophan residue to be an important to have changed the emission intensities

Copper(l) promoted allylic nucleophilic substitutions: a synthetic and mechanistic study

Allylic alkylations and substitutions promoted by copper(l) have been studied. These reactions are very useful from the synthetic point of view, since a wide variety of allylic substrates such as halides, esters, carbonates and even alcohols are activated towards substitutions. They can be carried out under acidic conditions and hence complement the widely used palladium catalysed reaction. The driving force for the reaction is the exchange of the poorly coordinating anion on the copper, usually perchlorate or tetrafluoroborate, for a good ligating anion from the allylic substrate. The reaction proceeds through a highly reactive, symmetrical intermediate. The various possibilities include an $\eta^3-\pi$ allylic complex of copper, a fluxional $\eta^2$ complex of the allylic cation and a free cation. Experiments designed to distinguish between the possibilities are described

Allylic Aminatian Promoted by Copper

A mild method for the synthesis of allylic amines by using a mixture of copper(II)perchlorate and copper metal is described

Allylic Activation by Copper(I): Reactivity Comparable with Catalysis by Palladium

Allylic chlorides and acetates accelerate the reaction between copper(II) perchlorate and copper metal powder to form copper(I) perchlorate which in turn is an extremely good catalyst for the activation of these substrates towards nucleophilic substitution