Chemical Reduction of a Nanosized [6]Cyclo-2,7-naphthylene Macrocycle

Zheng Zhou; Zheng Wei; Koki Ikemoto; Sota Sato; Hiroyuki Isobe; Marina A Petrukhina

doi:10.1002/anie.202100942

Chemical Reduction of a Nanosized [6]Cyclo-2,7-naphthylene Macrocycle

Angew Chem Int Ed Engl. 2021 May 10;60(20):11201-11205. doi: 10.1002/anie.202100942. Epub 2021 Apr 8.

Authors

Zheng Zhou¹, Zheng Wei¹, Koki Ikemoto², Sota Sato², Hiroyuki Isobe², Marina A Petrukhina¹

Affiliations

¹ Department of Chemistry, University at Albany, State University of New York, 1400 Washington Ave, Albany, NY, 12222, USA.
² Department of Chemistry, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033, Japan.

PMID: 33617079
DOI: 10.1002/anie.202100942

Abstract

Chemical reduction of a naphthylene macrocycle, [6]cyclo-2,7-naphthylene ([6]CNAP, 1), with alkali metals, Li and K, revealed the accessibility of the doubly-reduced state of 1. The macrocyclic 1^2- anion was isolated in different coordination environments and crystallographically characterized. The single-crystal X-ray diffraction confirmed the formation of contact-ion complexes with one Li⁺ and two K⁺ ions in THF, and a "naked" dianion in the solvent-separated ion product with K⁺ ions in the presence of 18-crown-6 ether. The detailed structural analysis of 1^2- showed that the π-conjugation over the biaryl linkages between naphthylene panels were enhanced upon two-fold reduction, which was rationally explained by theoretical calculations.

Keywords: X-ray diffraction; alkali metals; chemical reduction; macrocycles; structural study.

Abstract

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