Complexes of rhodium carbonylchloride and phosphorus(iii) cyanides in mediated electrochemical reduction of 2-carbomethoxy-2-methyl-1,1-dichlorocyclopropane

Electrochemical reduction of the complexes Rh(CO)ClL₂ [L = (EtO)₂PCN (1), Ph₂PCN (2)] and Rh₂(CO)₄L [L = P(CN)₃ (3), (4)] and their catalytic properties in electrochemical reduction of 2-carbomethoxy-2-methyl-1,1-dichloro-cyclopropane were studied. The catalytic electroreduction of a substrate at the reduction potentials of the central ion was developed for complexes2–4. This process is accelerated substantially for complexes2 and3 in the presence of anthracene.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1970–1972, October, 1995.     

Synthesis of formyl and carboxy derivatives of heterocycles by modification of 2-(2-aminovinyl)- benzofuran-5,6-dicarbonitriles

Procedures have been developed for the synthesis of 2-formylbenzofuran-5,6-dicarbonitriles, 5,6-dicyanobenzofuran-2-carboxylic acids, and formyldibenzo[b,d]furan-2,3-dicarbonitriles by modification of 2-(2-aminovinyl)benzofuran-5,6-dicarbonitriles with sodium periodate or Vilsmeier reagent.     

Synthesis of chalcones from 2-substituted 1-hydroxyindole-5,6-dicarbonitriles

Methods of synthesis of chalcones from 2-substituted 3-acetyl- and 3-formyl-1-hydroxyindole-5,6-dicarbonitriles under acidic conditions have been developed.     

Synthesis and Thermal Stability of Si-Containing Calcium Phosphates

Crystallography Reports - Si-containing calcium phosphates have been synthesized. The synthesized solid phases have been investigated by X-ray diffraction analysis, IR spectroscopy, and optical...     

Synthesis and structure of 2-phenylanthra[9,1-<Emphasis Type="Italic">bc</Emphasis>]pyrrol-6-one

Reduction of anti-1-benzoylanthraquinone oxime gave 2-phenylanthra[9,1-bc]pyrrol-6-one whose structure was determined by X-ray analysis. The molecule of 2-phenylanthra[9,1-bc]pyrrol-6-one is almost planar, and its crystalline structure is characterized by head-to-tail chains formed via intermolecular hydrogen bonds N-H ... O.     

X-ray photoelectron study of the structure and composition of organometal cluster systems

This paper gives the results of the study of the structure and composition of copper- and cobalt-containing complex compounds synthesized using acetylacetone and triethyleneglycoldimethacrylate as complexons. It was established by X-ray photoelectron, IR, UV, and ESR spectroscopy that the cluster nuclei differ in size from each other by about a factor of three. When acetylacetonate is used as a complexon, the nature of the metal determines the character of interactions during structure formation of cluster systems. In the case of triethyleneglycoldimethacrylate, the character of metal-complexon interactions is determined from the variation of the X-ray photoelectron spectrum of oxygen. Translated fromZhumal Struktumoi Khimii, Vol. 39, No. 6, pp. 1107–1112, November–December, 1998.     

Field electron emission form single-walled carbon nanotubes with deposited cesium atoms

It has been found that deposition g of cesium atoms on single-walled carbon nanotubes covered with potassium atoms not only drastically increases emission current but also considerably changes the shape of current-voltage characteristics of field electron emission, namely, the characteristics become nonlinear in Fowler-Nordheim coordinates. It has been assumed that this effect is associated with the fact that field electron emission in these layers comes from single-walled carbon nanotubes, which have p-type conductivity after potassium treatment, while deposition of cesium leads to the formation of p-n junctions near nanotube tips. Part of the applied voltage drops in p-n junction, thus causing a nonlinearity of current-voltage characteristics.     

Effect of the cesium and potassium doping of multiwalled carbon nanotubes grown in an electrical arc on their emission characteristics

The effect of cesium and potassium atoms deposited onto multiwalled carbon nanotubes grown in an electrical arc on their emission characteristics was studied. The current–voltage characteristics of the field electron emission of specimens with cesium or potassium doped multiwalled carbon nanotubes of this type were revealed to retain their linear character in the Fowler–Nordheim coordinates within several orders of magnitude of change in the emission current. The deposition of cesium and potassium atoms was shown to lead to a considerable increase in the emission current and a decrease in the work function φ of studied emitters with multiwalled nanotubes. The work function was established to decrease to φ ~ 3.1 eV at an optimal thickness of coating with cesium atoms and to φ ~ 2.9 eV in the case of doping with potassium atoms. Cesium and potassium deposition conditions optimal for the attainment of a maximum emission current were found.

     

Influence of Submicron Anthracite Particles on the Conditions of Aerosol Synthesis and the Properties of Carbon Nanotubes

Russian Physics Journal - Properties of single-walled carbon nanotubes (SWCNTs) obtained by the floating catalyst CVD method using ethyl alcohol and coal (anthracite and semi-anthracite) particles...