24176-58-7Relevant academic research and scientific papers
EPR and ENDOR spectroscopic study of the reactions of aromatic azides with gallium trichloride
Bencivenni, Giorgio,Cesari, Riccardo,Nanni, Daniele,El Mkami, Hassane,Walton, John C.
supporting information; experimental part, p. 5097 - 5104 (2010/12/24)
The reactions of gallium trichloride with phenyl and deuterio-phenyl azides, as well as with 4-methoxyphenyl azide and deuterium isotopomers, were examined by product analysis, CW EPR spectroscopy and pulsed ENDOR spectroscopy. The products included the corresponding anilines together with 4-aminodiphenylamine type dimers, and polyanilines. Complex CW EPR spectra of the radical cations of the dimers [ArNHC6H4NH 2]+ and trimers [ArNHC6H4NHC 6H4NH2]+ were obtained. These EPR spectra were analysed with the help of data from the deuterium-substituted analogues as well as the pulse Davies ENDOR spectra. DFT computations of the radical cations provided corroborating evidence and suggested the unpaired electrons were accommodated in extensive π-delocalised orbitals. A mechanism to account for the reductive conversion of aromatic azides to the corresponding anilines and thence to the dimers and trimers is proposed.
A ceric ammonium nitrate N-dearylation of N-p-anisylazoles applied to pyrazole, triazole, tetrazole, and pentazole rings: Release of parent azoles. Generation of unstable pentazole, HN5/N5-, in solution
Butler, Richard N.,Hanniffy, John M.,Stephens, John C.,Burke, Luke A.
, p. 1354 - 1364 (2008/04/12)
(Chemical Equation Presented) The reaction of cerium(IV) ammonium nitrate (CAN) with a range of N-(p-anisyl)azoles in acetonitrile or methanol solvents leads to N-dearylation releasing the parent NH-azole and p-benzoquinone in comparable yields. The scope and limitations of the reaction are explored. It was successful with 1-(p-anisyl)pyrazoles, 2-(p-anisyl)-1,2,3-triazoles, 2-(p-anisyl)-2H-tetrazoles, and 1-(p-anisyl)pentazole. The dearylation renders the p-anisyl group as a potentially useful N-protecting group in azole chemistry. The azole released in solution from 1-(p-anisyl)pentazole is unstable HN5, the long-sought parent pentazolic acid. p-Anisylpentazole samples were synthesized with combinations of one, two, and three 15N atoms at all positions of the pentazole ring. The unstable HN 5/N5- produced at -40°C did not build up in the solution but degraded to azide ion and nitrogen gas with a short lifetime. The 15N-labeling of the N3- ion obtained from all samples proved unequivocally that it came from the degradation of HN 5 (tautomeric forms) and/or its anion N5- in the solution.
Effect of Molecular Motion and Solvent Interactions on Nitrogen-15 Relaxation in Anilines
Lambert, Joseph B.,Daniel Stec, III
, p. 301 - 307 (2007/10/02)
Dipolar relaxation of 15N in anilines and anilinium ions is influenced by overall motion of the molecule, by rotation about the aryl-nitrogen bond, by inversion of the aniline nitrogen and by interactions of the NH2 or NH3+ group with the solve
