Doubly Strapped Redox-Switchable 5,10,15,20-Tetraaryl-5,15-diazaporphyrinoids: Promising Platforms for the Evaluation of Paratropic and Diatropic Ring-Current Effects
作者:Hikari Ochiai、Ko Furukawa、Haruyuki Nakano、Yoshihiro Matano
DOI:10.1021/acs.joc.0c02433
日期:2021.2.5
position of the methylene units; it decreased with increase in separation from the π-plane and central axis of the porphyrin ring. The NMR experiments also revealed that the degree of the diatropic ring currents was clearly related to the π-electron density of the porphyrin ring; the ring-current effects decreased as the charge increased from 0 to +2. These findings are also qualitatively supported by
本文提出了一系列新的化学稳定且可氧化还原转换的20π,19π和18π5,10,15,20-四芳基-5,15-二氮杂卟啉类化合物(TADAP),在二氮杂卟啉环的上方和下方都有两个烷基链带。三种类型的双重捆扎TADAPs的制备为使用镍(II)络合物内消旋- ñ - (2,6-二羟基苯基) -取代的TADAP和相应的脂族二酸作为前体。理论计算表明,无论其氧化态如何,所有捆绑的TADAP都具有基本平坦的π平面。发现烷基链带对DAP环的光学和电化学性质有轻微影响,特别是在氧化形式下。1个1 H NMR光谱用于评估20πTADAP的抗芳烃特性和18πTADAP指示剂的芳烃特性,并且观察到它们分别对亚甲基质子的化学位移表现出副热带和变径环电流效应。在空间上分开的烷基链。屏蔽和脱屏蔽的程度取决于亚甲基单元的位置。随着与卟啉环的π平面和中心轴的分离的增加,它降低。NMR实验还表明,变径环电流的程度与卟啉环的