Exhaustive electro-oxidation of ZnOEP in the presence of pyridine and Et 4 NPF 6 affords in high yield the new tetracationic porphyrin in which the four meso protons of ZnOEP are replaced by four pyridinium groups linked via their nitrogens: [ Zn -5,10,15,20-tetrakis(N-pyridiniumyl)-2,3,7,8,12,13,17,18-octaethylporphyrin]4+[Formula: see text], 1. The compound has been characterized by elemental analysis, 1 H NMR, and crystallography. The latter confirms the preparative electrosynthetic methodology and molecular structure of 1, and shows the porphyrin skeleton to adopt a severely nonplanar saddle conformation which minimizes steric crowding between the 12 peripheral substituents. As a consequence of the nonplanarity (and the high charge) of the complex, 1 exhibits significant red-shifts of the visible and Soret bands as well as a considerable broadening and loss of intensity of the latter. 1 first undergoes four one-electron reduction steps at the four pyridinium sites before the normal one-electron reduction of the porphyrin π-system.

中文翻译：

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四阳离子 Zn-meso-tetrapyridiniumyl-β-octaethylporphyrin 的电合成、电化学和晶体结构

吡啶和 Et 存在下 ZnOEP 的彻底电氧化4NPF6以高产率提供新的四阳离子卟啉，其中 ZnOEP 的四个中间质子被四个通过它们的氮连接的吡啶鎓基团取代：[ Zn -5,10,15,20-四(N-吡啶鎓基)-2,3,7 ,8,12,13,17,18-八乙基卟啉]4+[公式：见正文]， 1. 化合物已通过元素分析表征，1H NMR和晶体学。后者证实了 1 的制备电合成方法和分子结构，并显示卟啉骨架采用严重的非平面鞍形构象，最大限度地减少了 12 个外围取代基之间的空间拥挤。由于复合物的非平面性（和高电荷），1 表现出可见和 Soret 带的显着红移以及后者的显着展宽和强度损失。1首先在卟啉π-系统的正常单电子还原之前在四个吡啶鎓位点经历四个单电子还原步骤。