The oxidative dehydrocyclization of the 3-(indolizin-2′-yl)-2-oxoquinoxaline monopodand performed either electrochemically or under the action of molecular iodine affords new redox-active heterocyclophane consisting of the redox-switchable biindolizine fragment combined with the polyether-bridged π-deficient quinoxaline systems. The single-crystal X-ray diffraction study showed that the trioxaundecane chain of heterocyclophane adopts an extended conformation, and one of the phenyl substituents of the molecule closes the pseudocavity formed by the spacer from one of the sides. The cyclic voltammetric study of heterocyclophane in MeCN and DMF showed the three-step oxidation of the indolizine fragments accompanied by the single-electron transfer in each step. The first and third steps are reversible, and the second step is irreversible. The oxidation at potentials of the first peak gives rise to stable radical cations detected by the ESR method (g = 2.0024, a 2N = 0.26 mT).
通过电
化学或在分子
碘的作用下对 3-(
吲哚利嗪-2′-基)-2-氧代
喹喔啉单链进行氧化脱氢环化,可得到由氧化还原可切换的
生物吲哚利嗪片段与聚醚桥接的π缺陷
喹喔啉系统组成的具有氧化还原活性的新杂环烷。单晶 X 射线衍射研究表明,杂环烷的三氧杂
十一烷链呈延伸构象,分子中的一个苯基取代基从一侧封闭了由间隔物形成的假腔。杂环烷在 MeCN 和
DMF 中的循环伏安研究表明,
吲哚利嗪片段的氧化分为三步,每一步都伴随着单电子转移。第一步和第三步是可逆的,第二步是不可逆的。通过 ESR 方法检测,在第一峰电位下的氧化反应会产生稳定的自由基阳离子(g = 2.0024,a 2N = 0.26 mT)。