Volume 226, Issue 3 -

It is common to think of thiols as molecules that form self-assembled monolayers on gold or similar metals, they have also been used as corrosion inhibitors on copper and steel, but we show here that if the copper remains in thiol solution corrosion is accelerated and a thick layer of corrosion products with a very rough surface forms. The layer is superhydrophobic; repelling water so effectively that it rolls off leaving the surface completely dry. It is composed of a copper (I) thiolate complex and growth occurs quite rapidly under normal conditions. The film morphology depends upon the solvent and thiol used. The presence of organic amines in the solution alters the reaction leading to the formation of thinner layers by removing corrosion products into solution, allowing the removal of native oxide layers.

The viscosity of AOT/water/decane water-in-oil microemulsions exhibits a well-known maximum as a function of water/AOT molar ratio, which is usually attributed to increased attractions among nearly spherical droplets. The maximum can be removed by adding salt or by changing the oil to CCl 4 . Systematic small-angle X-ray scattering (SAXS) measurements have been used to monitor the structure of the microemulsion droplets in the composition regime where the maximum appears. On increasing the droplet concentration, the scattering intensity is found to scale with the inverse of the wavevector, a behavior which is consistent with cylindrical structures. The inverse wavevector scaling is not observed when the molar ratio is changed, moving the system away from the value corresponding to the viscosity maximum. It is also not present in the scattering from systems containing enough added salt to essentially eliminate the viscosity maximum. An asymptotic analysis of the SA XS data, complemented by some quantitative modeling, is consistent with cylindrical growth of droplets as their concentration is increased. Such elongated structures are familiar from related AOT systems in which the sodium counterion has been exchanged for a divalent one. However, the results of this study suggest that the formation of non-spherical aggregates at low molar ratios is an intrinsic property of AOT.

The reaction mechanism of Y + with CH 3 COCH 3 has been investigated with a DFT method. All the stationary points are determined at the UB3LYP/ECP/6-311 ++ G** level of the theory. Both the ground and the excited state potential energy surfaces are investigated in detail. The present results show that the title reaction starts with the formation of an O-attached complex (IM0) followed by C–O, C–H and C–C activation. The minimum energy reaction path is found to involve the spin inversion in the initial reaction step. The potential energy curve-crossing dramatically affects reaction exothermic. The present results may be helpful in understanding the mechanism of the title reaction and further experimental investigation of the reaction.

The oxidation of a anticholinergic drug, Atropine sulfate monohydrate (ASM) by diperiodatocuprate(III) (DPC) has been investigated spectrophotometrically in aqueous alkaline medium at a constant ionic strength of 0.50 mol dm -3 . The reaction between diperiodatocuprate(III) and atropine sulfate exhibits 1:2 stoichiometry (atropine sulfate: diperiodatocuprate(III)). The main oxidation products were identified and confirmed by spectral studies including IR, 1 H NMR and GC-MS. A suitable mechanism is proposed. The order with respect to diperiodatocuprate(III) concentration was unity, while the order with respect to atropine sulfate concentration was less than unity over the concentration range studied. The rates increased with an increase in alkali concentration and decreased with an increase in periodate concentration. The activation parameters with respect to slow step of the mechanism were calculated and the thermodynamic quantities we are also determined. Kinetic experiments suggest that [Cu(OH) 2 (H 3 IO 6 )] - is the reactive species of copper(III).