117566-79-7Relevant academic research and scientific papers
Magnetostructural study of substituted α-nitronyl aminoxyl radicals with chlorine and hydroxy groups as crystalline design elements
Juergens, Oriol,Cirujeda, Joan,Mas, Montse,Mata, Ignasi,Cabrero, Araceli,Vidal-Gancedo, Jose,Rovira, Concepcio,Molins, Elies,Veciana, Jaume
, p. 1723 - 1730 (1997)
We present a new family of phenyl substituted α-nitronyl aminoxyl radicals which contain hydroxy- and chlorine-substituents as crystal engineering tools. The magnetic behaviour of these radicals strongly differs in dimensionality and strength, showing in all cases antiferromagnetic interactions. We have determined the X-ray crystal structure and analysed the crystal packings of these radicals. From this analysis all the observed magnetic properties can be conveniently rationalized by only considering the close contacts of NO groups of neighbouring molecules according to the generally accepted mechanisms for intermolecular magnetic interactions. Beside the strong O-H...O(-N) hydrogen bonds and the weaker C-H...O(-N) hydrogen bonds, weak Cl...H bonds also seem to play a significant role in determining the molecular arrangement in the solid state and, therefore, the magnetic properties. In only one case are close Cl...Cl contacts observed, pointing to attractive interactions between chlorine atoms.
SUBSTITUENT EFFECT ON THE REACTION OF 2-(SUBSTITUTED PHENYL)-4,5-DIHYDRO-4,4,5,5-TETRAMETHYLIMIDAZOL-1-OXYL 3-OXIDES WITH NITRIC OXIDE: AN EXPERIMENTAL AND MNDO STUDY
Shimomura, Osamu,Abe, Kazuhisa,Hirota, Minoru
, p. 795 - 798 (2007/10/02)
The relative rate constants of the oxygen transfer reaction of 2-(substituted phenyl)-4,5-dihydro-4,4,5,5-tetramethylimidazol-1-oxyl 3-oxides with nitric acid have been measured by using liquid chromatography (h.p.l.c.).The Hammett ρ value (-0.37) indicates that electron-donating substituents favour the reaction.This can be explained by a mechanism which includes electron transfer to nitric oxide and can be rationalised by frontier orbital energies and electron densities on the nitroxyl oxygen calculated by semiempirical MNDO methods.
