Planar Subporphyrin Borenium Cations

Subporphyrin borenium cations with a carborane counterion have been prepared by treatment of B-methoxy subporphyrins with the silylium reagent Et3Si(CH6B11Br6). In contrast to the distinctly domed subphthalocyanine borenium cation, a nearly planar structure with sp2 hybridized boron is found in the X-ray structure of the triphenylsubporphyrin borenium cation. The cations exhibit absorption and fluorescence spectra that are quite similar to those of B-methoxy subporphyrins. B-phenyl subporphyrins were prepared in good yield by reaction of subporphyrin borenium cations with phenyllithium.带有碳硼烷反离子（carborane counterion）的亚卟啉硼鎓阳离子（Subporphyrin borenium cations），可通过用硅鎓试剂（silylium reagent）Et3Si(CH6B11Br6)处理B-甲氧基亚卟啉（B-methoxy subporphyrins）制得。与结构明显呈穹顶状的亚酞菁硼鎓阳离子（subphthalocyanine borenium cation）不同，三苯基亚卟啉硼鎓阳离子（triphenylsubporphyrin borenium cation）的X射线晶体结构（X-ray structure）显示，其具有近乎平面的构型，且硼原子为sp²杂化（sp2 hybridized boron）。该类阳离子的吸收光谱与荧光光谱与B-甲氧基亚卟啉颇为相似。B-苯基亚卟啉（B-phenyl subporphyrins）可通过亚卟啉硼鎓阳离子与苯基锂（phenyllithium）的反应以高产率制得。