Switching between Aromatic and Antiaromatic 1,3-Phenylene-Strapped [26]- and [28]Hexaphyrins upon Passage to the Singlet Excited State

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• 作者：Young Mo Sung ; Juwon Oh ; Woojae Kim ; Hirotaka Mori ; Atsuhiro Osuka ; Dongho Kim
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：September 23, 2015
• 年：2015
• 卷：137
• 期：37
• 页码：11856-11859
• 全文大小：302K
• ISSN：1520-5126

文摘

We have demonstrated aromaticity reversal in the singlet excited states of internally 1,3-phenylene-strapped [26]- and [28]hexaphyrins (P26H and P28H). P26H displays a broad and reduced singlet-excited-state absorption spectrum, whereas P28H exhibits a sharp and intense singlet-excited-state absorption spectrum; both are in contrast to the ground-state absorption spectra, strongly indicating aromaticity reversal in the singlet excited state. Furthermore, magnetic and topological indices of aromaticity such as nucleus-independent chemical shift and harmonic oscillator model of aromaticity values for P26H and P28H also suggest that their singlet excited states become antiaromatic and aromatic, respectively.