Dipartimento di Chimica Organica A. Mangini, Università di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy.
Org Biomol Chem. 2010 Nov 21;8(22):5097-104. doi: 10.1039/c0ob00084a. Epub 2010 Aug 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 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.
三氯化镓与苯和氘代苯叠氮化物，以及 4-甲氧基苯叠氮化物和氘同位素物的反应通过产物分析、连续波 EPR 光谱和脉冲 ENDOR 光谱进行了检查。产物包括相应的苯胺以及 4-二苯胺基二聚体和聚苯胺。通过氘取代类似物以及脉冲 Davies ENDOR 光谱的数据，获得了二聚体[ArNHC(6)H(4)NH(2)]+˙和三聚体[ArNHC(6)H(4)NHC(6)H(4)NH(2)]+˙自由基阳离子的复杂连续波 EPR 光谱。DFT 计算为自由基阳离子提供了佐证，并表明未配对电子被容纳在广泛的π离域轨道中。提出了一个解释芳香族叠氮化物还原转化为相应苯胺，然后转化为二聚体和三聚体的机制。
