Norbiphenylene anions

When the bistrimethylammonium iodide 155 is treated with the dimeth-ylsulfoxide anion, a stable deep brown solution is obtained (146). Addition of water leads to two dimers, one of which was identified as 158. This result is consistent with the formation of the norbiphenylene anion 156, which upon protonation gives 157 and eventually the two dimers. 

The norbiphenylene anion (XXXIII) and homobiphenylene cation (XXXIV) are isoelectronic with biphenylene. 

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