2(5H)-Furanone and 5-Hydroxy-2(5H)-furanone: Reactions and Syntheses Based on Them

Russian Journal of General Chemistry - This review summarizes the data on 2(5H)-furanone, 5-hydroxy-2(5H)-furanone, and some substituted hydrofuranones with respect to their poorly studied or...     

Catalymetric Determination of Rhodium Based on the Reaction of the Oxidation of Triphenylamine-4-Sulfonic Acid by Sodium Periodate

The catalytic activity of rhodium(III) was studied in the reaction of the oxidation of triphenylamine-4-sulfonic acid by sodium periodate at pH 3. The dependence of the reaction rate on the technique of catalyst preparation, the presence of activators, the concentrations of the components, and the acidity and temperature of solutions was revealed. A sensitive and selective method for the catalymetric determination of rhodium(III) is proposed and tested with synthetic mixtures.     

Dynamics of Si-H vibrations in an amorphous environment

We present results of the first vibrational photon-echo, transient-grating, and temperature dependent transient-bleaching experiments on a-Si:H. Using these techniques, and the infrared light of a free electron laser, the vibrational population decay and phase relaxation of the Si-H stretching mode were investigated. Careful analysis of the data indicates that the vibrational energy relaxes directly into Si-H bending modes and Si phonons, with a distribution of rates determined by the amorphous host. Conversely, the pure dephasing appears to be single exponential, and can be modeled by dephasing via two-phonon interactions.     

2(5H)-furanone in the vilsmeier—haak reaction. Synthesis of β-substituted furans. Molecular structures of 3-dimethylaminomethylene-5-formyl-2(3H)-furanone and dimethylammonium 3,5-di(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidenemethyl)-2-furanolate

The reaction of 2(5H)-furanone with the Vilsmeier-Haak-Arnold reagent and subsequent addition of concentrated aqueous HClO₄ to the reaction mixture give (3-dimethylaminomethylen-2-oxo-3H-5-furanyl)methylenimmonium perchlorate, whose hydrolysis under various conditions leads to 3-dimethylaminomethylene-5-formyl-2(3H)-furanone or to the potassium salt of 5-hydroxy-2,4-furandicarbaldehyde. The reaction of these products with CH-acids was studied. The structures of the key compounds of this work have been proved by the method of X-ray diffraction analysis.Kuban State Technological University. 350072 Krasnodar, Russia; email:gemm18803@yahoo.com. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 24–34, January, 1999.     

Electrochemical dissolution of Co<Subscript>3</Subscript>O<Subscript>4</Subscript> in acidic solutions

The cyclic voltammetry method was used to study the regularities of the electrochemical behavior of cobalt cobaltite in an acidic medium. It is shown that cathodic reduction of Co₃O₄ in the studied range of potentials of +1.0 to −0.8 V is a multistage process occurring according to the scheme: