The 13C magnetic resonance of some N-aryl 2-ethoxycarbonyl 2-methyl benzo(e)indoxyles and N-aryl 2-methyl benzo(e)indoles have been investigated. Attribution of each signal was performed (except only one indetermination).
M. Ramah, G. Schmitt, J. Vebrel, B. Laude
Stereospecific synthesis of heterosubstituted 1,5 hexadienes is realised. These diethers rearrange preferentially through a chair transition state. The contribution of the boat transition state is detected. The Z/E olefinic bond ratio of the dienol ethers obtained reveals that the reaction is not governed by the free energy change for the conversion of a substituent from the equatorial to the axial position but rather by the relative thermodynamic stability of the isomers Z.Z. and E.E.
R. Abdelhedi, M.L. Bouguerra, J.C. Pommelet, J. Chuche
Adsorption isotherms and isosteric heats of adsorption were measured, at three temperatures in the range 293-373 K, for the interaction of carbon monoxide with a prereduced Fe2O3/Al2O3 catalyst. A decrease in heat of adsorption with increasing surface coverage was observed, and the isotherms conformed well at low coverage to the Freundlich equation, indicating an energetically heterogeneous catalyst surface. Entropy calculations indicate that the surface species are extremely mobile, even at low coverages. Consideration of previous infrared studies of CO adsorption on iron catalyst suggest that the adsorbed layer is entirely of CO-type structure, formed by interaction of CO with surface ionic sites.
E.S.R. study of oriented V2O5 (1.6 ± 0.2) H2O gel film shows anisotropy. Physical properties and particularly electrical conductivity depend to a far extent on this anisotropy. On the other hand, this work shows that local order around V (IV) sites does not depend neither on oriented not on disoriented species. Percentages of oriented species as well as of disoriented ones have been determined by calculated experimental spectra.
N. Gharbi, J. Livage
A series of experiments are designed to show the effects of temperature, catalysts, ionic strength and reactant concentrations on the rate of persulfate ion-iodide ion reaction. The experiments can be devised to take varying lengths of time depending on the accuracy desired. The experiment as described in this paper is brief, and uses commonly available equipment. It is suitable for a short laboratory period and also can be very successful as a lecture demonstration experiment.