A series of 2,2'-bibenzimidazolium salts has been prepared by N,N'-bridging using dihaloalkanes. These salts may be reduced by either one or two electrons to the corresponding cation radical or neutral 2,2'-bibenzimidazolylidene. The latter species undergoes a chemiluminescent reaction with dioxygen to afford conformationally unique ureaphanes. Two benzimidazole molecules may be joined by N,N'-bridges to form bis(benzimidazolium) salts which may be deprotonated with sodium hydride. Subsequent intramolecular 2,2'-coupling leads to the same 2, 8'-bibenzimidazolinylidenes. The structural features of the ureaphane oxidation products have been studied by X-ray crystallography and NMR. An equimolar mixture of a 2,2'-bibenzimidazolium salt and the corresponding 2,2'-bibenzimidazolinylidene will coproportionate to form the analogous cation radical.
An aza-analogue of TTF1: 1,1′;3,3′-bistrimethylene-2,2′-diimidazolinylidine
作者:Zhiqiang Shi、Veronique Goulle、Randolph P. Thummel
DOI:10.1016/0040-4039(96)00290-0
日期:1996.4
Bulk electrolysis of 1,1′;3,3′-bistrimethylene-2,2′-biimidazolium dibromide at −1.6 V in acetonitrile provides the air sensitive 1,1′;3,3′-bistrimethylene-2,2′-diimidazolinylidine which was characterized by 1H and 13C NMR. The corresponding dinaphtho-fused species, prepared by deprotonation of a bis-trimethylene bridged bis-naphth[2,3]imidazolium dibromide, reacts readily with air to form a syn-ureaphane
1,1.6';; 3,3'-双三亚甲基-2,2'-二咪唑鎓二溴化物在乙腈中大量电解,对空气敏感的1,1'; 3,3'-双三亚甲基-2,2'-二咪唑啉基吡啶用1 H和13 C NMR表征。通过双三亚甲基桥联的双萘[2,3]咪唑鎓二溴化物的去质子化反应制得的相应的萘并噻吩与空气容易反应形成顺式脲基。