shifted UV–Vis absorptions compared to their core unsubstituted congeners. However, proton NMR spectroscopy demonstrated that these derivatives retained strong diamagnetic ring currents and the presence of the internal alkyl substituents had little effect on the global aromatic characteristics. Nevertheless, the UV–Vis spectra of N-methyl-oxybenzi- and N-methyl-oxypyriporphyrins were dramatically altered
麦克唐纳型“3 + 1”的的缩合Ñ -methyltripyrrane与得到一套匹配的一系列二醛的Ñ -methylporphyrins,Ñ -methylheteroporphyrins,Ñ -methyloxybenziporphyrin,Ñ -methyloxypyriporphyrin,Ñ -methyltropiporphyrin和Ñ -methylcarbaporphyrin醛。内消旋-未取代的杂
卟啉以前很少被探索,并且该策略也用于制备N-未取代的21-氧杂-,21-
硫杂和21-
硒杂
卟啉。在任何情况下,N与它们的核心未取代同类物相比,-甲基
卟啉类化合物显示出较弱的,红移的紫外可见吸收。然而,质子NMR光谱表明,这些衍
生物保留了强的抗磁性环电流,并且内部烷基取代基的存在对整体芳族特性几乎没有影响。但是,N-甲基-氧基苯并
卟啉和N-甲基-氧
吡啶并
卟啉的UV-Vis光谱发生了显着变化