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Journal articles
Hexaphyrin-Cyclodextrin Hybrids: A Nest for Switchable Aromaticity, Asymmetric Confinement, and Isomorphic Fluxionality
Abstract : Conformational control over the highly flexible π-conjugated system of expanded porphyrins is a key step toward the fundamental understanding of aromaticity and for the development of molecular electronics. We have synthesized unprecedented hexaphyrin-cyclodextrin (HCD) capped hybrids in which the hexaphyrin part is constrained in a planar rectangular conformation in either a 26 or a 28 π-electron oxidation state ([26]/[28]HCD). These structures display strong aromaticity and antiaromaticity, respectively, exhibit markedly different chiroptical properties, and are interconvertible upon the addition of DDQ or NaBH(OAc)3 , thus affording a rare switchable aromatic-antiaromatic system with a free-base expanded porphyrin. Conformational analysis revealed discrimination of the two coordination sites of the hexaphyrin, one of which was coupled to a confined asymmetric environment, and fluxional behavior consisting of apparent rotation of the hexaphyrin cap through a shape-shifting mechanism.
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01231166
Contributor : Laurent Jonchère Connect in order to contact the contributor
Submitted on : Thursday, November 19, 2015 - 3:47:29 PM
Last modification on : Friday, December 10, 2021 - 3:52:09 PM
Contributor : Laurent Jonchère Connect in order to contact the contributor
Submitted on : Thursday, November 19, 2015 - 3:47:29 PM
Last modification on : Friday, December 10, 2021 - 3:52:09 PM
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