Radical efficiency and ionic reactions of some unsymmetrical azo compounds

Abstract

Compounds with the structure R1-N=y-RZ $ecompose either thermally or photochemically to yield nitrogen and the radicals R' and R'. These radicals, under appropriate conditions, can either act as polymerization initiators or can be trapped by radical scavengers such as iodine. In the presence of suitable reagents the title compounds behave like diazonium salts and thus, since they are relatively stable, may provide a safe and readily available diazonium ion source.

Rapid mineralization of methyl orange by nanocrystalline-assembled mesoporous Cu2O microspheres

“…Corresponding with equations (6) and (7), the electrons are able to activate oxygen molecules and produce • -O 2 as well as H 2 O 2 , the amount of which has an observable increase under the illumination of visible light, demonstrated by EPR and PL. It is concluded that The XPS spectra of samples With what is known, the -N=Nbond could be decomposed by Cu (I) via the Sandmeyer reaction [13], during which the carbon center radicals are in situ generated (equation ( 8)) [2]. In this study, GC-MS results demonstrate that MO is decomposed to xylene and ethylbenzene, which is in good coordination with the results from former studies, that carbon center radicals such as methyl radical and phenyl radical have reconnected with each other, to produce xylene or ethylbenzene [2].…”

“…In system III (nitrogen/dark condition), the removal of MO in 40 min decreases to 40%. By Sandmeyer reaction [13], in the absence of visible light as well as oxygen, MO could still be partially removed by MCMs. The absorption ability of MCMs contribute to the removal ability of MO too.…”

“…It is demonstrated by previous studies, that MO can be effectively removed by Cu 2 O under the illumination of visible light, during the process. Reactive oxygen species (ROS) such as • -O 2 and H 2 O 2 play an important role in photofading, as well as mineralizing the intermediate products [8], while Cu (I) radical released by Cu 2 O could also decolorize MO via the Sandmeyer reaction [13]. The roles of ROS and Cu (I) radical in the degradation process of MO in the absence of light has been discussed by some studies [2,6,14] while to the best of our knowledge, the discrete roles of ROS and Cu (I) radical to the fading and mineralization of MO under the illumination of visible light, were still rarely reported.…”

Thermally stable, photoactive polymerizable diazenes. Applications in polymer technology

“…A prolific and creative research program in the general area of polymerizable diazenes has been Scheme 1. lead by Nuyken. Reactive azo groups pendent to a backbone of poly(styrene), 3 poly(methylacrylamide-co-methacrylate), 4 and polycarbonate 5 have been prepared and used to great advantage by Nuyken. Applications of these compounds by Nuyken include the preparation of graft copolymers, new crosslinked polymer systems, and coreshell polymers.…”