Abstract
The six-membered cyclic 1,4-radical cation 2 •+ forms a “twisted π-space” due to noncoplanarity of the cumyl radical 3 • and cumyl cation 3 + originating from a chair conformation of the central cyclohexane ring system. The results of substituent effects on absorption wavelengths of 2 •+ indicate that both through-space (TS) and through-bond (TB) orbital interactions operate in a “twisted π-space” of 2 •+, resulting in the theoretically maximal orbital interactions between 3 • and 3 +. An operation of similar TS and TB orbital interactions is also suggested in the excited-state biradical 1 2 ••* by the results of substituent effects on thermoluminescence wavelengths.
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References
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Acknowledgments
H. I. gratefully acknowledges financial support from a Grant-in-Aid for Scientific Research on Priority Areas (Area No. 2007, Emergence of Highly Elaborated π-Space and Its Function) and others from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan.
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Ikeda, H., Matsui, Y., Ohta, E. (2015). Unique Orbital Interactions in the Ground and Electronically Excited States of Biradicals Brought about by the Existence of “Twisted π-Space”. In: Akasaka, T., Osuka, A., Fukuzumi, S., Kandori, H., Aso, Y. (eds) Chemical Science of π-Electron Systems. Springer, Tokyo. https://doi.org/10.1007/978-4-431-55357-1_18
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DOI: https://doi.org/10.1007/978-4-431-55357-1_18
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