Kinetics and Mechanism of the Oxidative Regeneration of Carbonyl Compounds from Oximes by Cetyltrimethylammonium Permanganate

The oxidative deoximination of several aldo- and keto-oximes by cetyltrimethylammonium permanganate (CTAP), in dichloromethane, proceeding through the formation of a cyclic intermediate, in the rate-determining step, has been proposed.

Kinetics and mechanism of the oxidation of Substituted Benzylamines by Oxo(Salen)Manganese (V) Complexes

The oxidation of substituted benzylamines by oxo(salen) Mn(V) complexes, to the corresponding aldimine, proceeds through a hydride ion transfer from the amine to the oxidant.

Kinetics and Mechanism of the Oxidative Regeneration of Carbonyl Compounds from Oximes by Cetyltrimethylammonium Permanganate

The oxidative deoximination of several aldo- and keto-oximes by cetyltrimethylammonium permanganate (CTAP), in dichloromethane, proceeding through the formation of a cyclic intermediate, in the rate-determining step, has been proposed.

Unexpected Sequential NH3/H2O Solid/Gas Phase Ligand Exchange and Quasi-Intramolecular Self-Protonation Yield [NH4Cu(OH)MoO4], a Photocatalyst Misidentified before as (NH4)2Cu(MoO4)2

[NH₄Cu(OH)MoO₄] as active photocatalyst in the decomposition of Congo Red when irradiated by UV or visible light has been prepared in an unusual ammonia/water ligand exchange reaction of [tetraamminecopper(II)] molybdate, [Cu(NH₃)₄]MoO₄. [Cu(NH₃)₄]MoO₄ was subjected to moisture of open air at room temperature. Light blue orthorhombic [Cu(NH₃)(H₂O)₃]MoO₄ was formed in 2 days as a result of an unexpected solid/gas phase ammonia-water ligand exchange reaction. This complex does not lose its last ammonia ligand on further standing in open air; however, a slow quasi-intramolecular (self)-protonation reaction takes place in 2-4 weeks, producing a yellowish-green microcrystalline material, which has been identified as a new compound, [NH₄Cu(OH)MoO₄], ( a = 10,5306 Å, b = 6.0871 Å, c = 8.0148 Å, β = 64,153°, C2, Z = 4). Mechanisms are proposed for both the sequential ligand exchange and the self-protonation reactions supported by ab initio quantum-chemical calculations and deuteration experiments as well. The [Cu(NH₃)(H₂O)₃]MoO₄ intermediate transforms into NH₄Cu(OH)(H₂O)₂MoO₄, which loses two waters and yields [NH₄Cu(OH)MoO₄]. Upon heating, both [Cu(NH₃)₄]MoO₄ and [Cu(NH₃)(H₂O)₃]MoO₄ decompose, losing three NH₃ and three H₂O ligands, respectively, and stable [Cu(NH₃)MoO₄] is formed from both. The latter can partially be hydrated in boiling water into [NH₄Cu(OH)MoO₄. This compound can also be prepared in pure form by boiling the saturated aqueous solution of [Cu(NH₃)₄]MoO₄. All properties of [NH₄Cu(OH)MoO₄] match those of the active photocatalyst described earlier in the literature under the formulas (NH₄)₂[Cu(MoO₄)₂] and (NH₄)₂Cu₄(NH₃)₃Mo₅O₂₀.

Copper nanoparticles grafted on carbon microspheres as novel heterogeneous catalysts and their application for the reduction of nitrophenol and one-pot multicomponent synthesis of hexahydroquinolines

Carbon microsphere-supported Cu nanoparticles were fabricated, characterized, and applied for synthesis.

Alkane isomers: presence in petroleum ether and complexity

The presence and absence of alkane isomers in petroleum and petroleum derivatives depend on the complexity of these structures. It was assumed that the more complex the structure is the less probable it is that that the molecule can be detected in any petroleum derivative. Complexity is a vague concept, which has not been defined in quantitative terms yet, and therefore there is no experimental method, which could be used to determine 'complexity'. Mass spectrometry and infrared spectroscopy in combination with gas chromatography were used to identify the various structural isomers of alkanes in petroleum ether. The isomers were categorised in quantitative terms by using topological indices and linear discriminant analysis. It was found that alkanes possessing a more complex, highly branched structure are less probable to be detected in petroleum ether than isomers with a simpler backbone structure. It was proposed that the experimental 'measure' of the complexity of isomer(i) should be proportional to 1/C(i), where C(i), denotes the concentration of isomer(i) in a (primary) petroleum derivative.

In vitro study of elements in herbal remedies

Decreased glucose tolerance is a first sign of diabetes mellitus and therefore rigorous control must be taken in carbohydrate and lipid metabolisms. Herbal remedies (lyophilized extracts of Myrtilli folium and Phaseoli fructus sine seminibus (L1), Myrtilli folium, Phaseoli fructus sine seminibus, and Salviae folium (L2) are traditionally used in mid-European folk medicine and in common adjuvant therapy for the prevention of complications in type 2 diabetes. Significant iron (355.7 +/- 13.8 mg/kg) and zinc (84.73 +/- 1.83 mg/kg) concentration was found in L1 and chromium (3.82 +/- 2.71 mg/kg) in L2. Ion concentrations in teas made from L1 and L2 are relatively low because the quantities of metal ions in teas do not cover the daily need, although the teas are good sources for some elements. According to the Recommended Daily Allowances, the tea of L1 is a good source for iron and manganese, whereas for chromium, the tea of L2 is better. For evaluating the element bioavailability, an in vitro dialysis system was applied to determine the element transfer from tea of the lyophilized sample to the plasma (buffer pH=7.4). Measurements showed that the elements transferred between 6.90% (iron from tea of L2) and 90.05% (chromium from tea of L2) through the membrane from teas to the plasma. Metal ions in teas of herbal remedies might contribute to the favorable therapeutic effect of preventing complications, because they might transfer through the membranes in relatively high percentages.

Kinetics and mechanism of the Oxidative regeneration of Carbonyl Compounds from Phenylhydrazones by Tetramminecopper(2+) Bis (Permanganate)

The oxidation of aldo- and keto-phenylhydrazones by tetraamminecopper(2+) bis(permanganate) (TACP), in aqueous acetic acid, proceeds through a mechanism involving the formation of a cyclic activated complex, in the rate-determining step.