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Title: Reduction of π‐Expanded Cyclooctatetraene with Lithium: Stabilization of the Tetra‐Anion through Internal Li + Coordination
Abstract

The chemical reduction of a π‐expanded polycyclic framework comprising a cyclooctatetraene moiety, octaphenyltetrabenzocyclooctatetraene, with lithium metal readily affords the corresponding tetra‐anion instead of the expected aromatic dianion. As revealed by X‐ray crystallography, the highly contorted tetra‐anion is stabilized by coordination of two internally bound Li+, while two external cations remain solvent separated. The variable‐temperature7Li NMR spectra in THF confirm the presence of three types of Li+ions and clearly differentiate internal binding, consistent with the crystal structure. Density‐functional theory calculations suggest that the formation of the highly charged tetra‐reduced carbanion is stabilized through Li+coordination under the applied experimental conditions.

 
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Award ID(s):
1834750 2003411 1726724
NSF-PAR ID:
10236773
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Angewandte Chemie International Edition
Volume:
60
Issue:
7
ISSN:
1433-7851
Page Range / eLocation ID:
p. 3510-3514
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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