title: EPR and ENDOR spectroscopic study of the reactions of aromatic azides with gallium trichloride.
abstract: 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 [ArNHC(6)H(4)NH(2)](+)˙ and trimers [ArNHC(6)H(4)NHC(6)H(4)NH(2)](+)˙ 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.
authors: Dipartimento di Chimica Organica A. Mangini, Università di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy.
authors: Giorgio
authors: G
authors: Bencivenni
authors: Riccardo
authors: R
authors: Cesari
authors: Daniele
authors: D
authors: Nanni
authors: Hassane
authors: H
authors: El Mkami
authors: John C
authors: JC
authors: Walton