Azoxy

Abstract: Partial table of contents: Electronic Structure of Hydrazo, Azo and Azoxy Compounds (H. Basch & T. Hoz). Mass Spectra of Hydrazo, Azo and Azoxy Compounds (T.-W. Chan & S. Tam). NMR Spectroscopy of Azo, Azoxy and Hydrazo Compounds (J. Mason). Acidity, Basicity and Complex Formation (T. Klap?tke). Electronic Effects of Hydrazo, Azo and Azoxy Groups (J. Shorter). The Photochemistry of the Hydrazo, Azo and Azoxy Groups (W. Horspool). Radiation Chemistry of Azo and Hydrazo Compounds (Z. Alfassi). Radical Reactions of Azo, Hydrazo and Azoxy Compounds (G. Koga, et al.). Biological Formation and Reactions of Hydrazo, Azo and Azoxy Groups (D. Banthorpe). Safety and Environmental Effects of Azo Compounds (V. Glezer). Indexes.

Abstract: Copper is a low-cost plasmonic metal. Efficient photocatalysts of copper nanoparticles on graphene support are successfully developed for controllably catalyzing the coupling reactions of aromatic nitro compounds to the corresponding azoxy or azo compounds under visible-light irradiation. The coupling of nitrobenzene produces azoxybenzene with a yield of 90 % at 60 °C, but azobenzene with a yield of 96 % at 90 °C. When irradiated with natural sunlight (mean light intensity of 0.044 W cm−2) at about 35 °C, 70 % of the nitrobenzene is converted and 57 % of the product is azobenzene. The electrons of the copper nanoparticles gain the energy of the incident light through a localized surface plasmon resonance effect and photoexcitation of the bound electrons. The excited energetic electrons at the surface of the copper nanoparticles facilitate the cleavage of the NO bonds in the aromatic nitro compounds. Hence, the catalyzed coupling reaction can proceed under light irradiation and moderate conditions. This study provides a green photocatalytic route for the production of azo compounds and highlights a potential application for graphene.

Abstract: Alignment by electric or magnetic fields of molecules comprising the liquid crystalline phase of a nematogenic material is manifested in proton magnetic resonance spectroscopy by the appearance of nuclear dipole‐dipole fine structure. Additionally, much larger splittings ranging up to 300 G are observed in the deuterium magnetic resonance spectrum of deuterium substituted nematogens. These latter splittings arise from perturbation of the Zeeman levels by the quadrupole coupling constant of deuterium and have been of value in elucidating structure and organization in nematic phases. Results of NMR studies on nematogens based on azoxy and carboxylic compounds are presented. Use of nematic phases as ordering matrices for molecules such as benzene, toluene, naphthalene, and stilbene are discussed. Some preliminary results on effects of electric fields and dissolved cholesteryl acetate on orientation and organization of nematogens also are presented. In addition, quadrupole coupling constants for deuterium bound to sp2 and sp3 carbon and for deuterium bound to oxygen in a carboxylic acid dimer were determined for a few selected compounds.