An Oxygen‐
<i>peri</i>
‐Bridged Quinolinium Cation and Its Monoradical Counterpart
作者:Raghavendhar R. Kotha、John J. Nash、Hilkka I. Kenttämaa
DOI:10.1002/ejoc.201601572
日期:2017.3.17
inium cation, the cyclization is calculated to be exoergic by 8.7 kcal mol-1 with a free energy barrier of 14.0 kcal mol-1. The cyclized product is the first experimentally observed oxygen-peribridged naphthalene derivative. It displays low reactivity. However, it's monoradical counterpart is highly reactive and undergoes typical radical reactions.
摘要:通过离子阱质谱仪中 2,4-二碘-5-硝基喹啉鎓阳离子的两个碘原子和 NO● 自由基的碰撞激活解离 (CAD) 尝试生成 σ,σ,π-三自由基。然而,产物的反应性与单自由基而非三自由基一致。对其形成机制进行了探讨。在第一个 CAD 步骤中,失去一个碘原子以生成 2-iodo-5-nitro-4-dehydroquinolinium 阳离子。量子化学计算表明,在第二个 CAD 步骤中,C-4 处的自由基位点与相邻的 NO2 基团相加,然后失去 NO●,生成 2-iodo-4-oxyl-5-dehydroquinolinium 阳离子。计算还表明,在第三个 CAD 步骤中,该阳离子环化形成氧周桥连的 2-碘喹啉鎓阳离子,然后失去剩余的碘原子,生成异张力 4,5-氧周桥连 2-脱氢喹啉鎓阳离子。对于类似的 4-oxyl-5-dehydroquinolinium 阳离子,环化计算为放热 8.7