Synthesis, aromatization and cavitates of an oxanorbornene-fused dibenzo[de,qr]tetracene nanobox.

Han Chen,Zeming Xia,Qian Miao

doi:10.1039/d1sc06553j

Abstract

Oxanorbornene-fused double-stranded macrocycles, represented by kohnkene, are not only synthetic precursors toward short segments of zigzag carbon nanotubes but also typical cavitands processing an intrinsic cavity. However, their capability to bind guest molecules in solution remained unexplored. Herein we report a new member of oxanorbornene-fused double-stranded macrocycles, which is named a nanobox herein because of its shape. Reductive aromatization of this oxanorbornene-fused nanobox leads to observation of a new zigzag carbon nanobelt by high resolution mass spectroscopy. The fluorescence titration and NMR experiments indicate that this nanobox encapsulates C70 in solution with a binding constant of (3.2 ± 0.1) × 106 M−1 in toluene and a high selectivity against C60 and its derivatives. As found from the X-ray crystallographic analysis, this nanobox changes the shape of its cross-section from a rhombus to nearly a square upon accommodating C60.

Highlights

Oxanorbornene-fused double-stranded macrocycles, represented by kohnkene (Fig. 1a), have received considerable attention because they are synthetic precursors toward short segments of zigzag carbon nanotubes[1,2,3,4,5,6] and because they are typical cavitands processing well de ned cavities as a result of the intrinsic curvature of the oxanorbornene moieties.[7]
We report a new member of oxanorbornene-fused double-stranded macrocycles, which is named a nanobox because of its shape. Reductive aromatization of this oxanorbornene-fused nanobox leads to observation of a new zigzag carbon nanobelt by high resolution mass spectroscopy
Kohnkene was synthesized by Kohnke, Stoddart and coworkers in 1987 during the targeted synthesis of [12]cyclacene,[8,9] and named a er its creator

Summary

Introduction

Oxanorbornene-fused double-stranded macrocycles, represented by kohnkene (Fig. 1a), have received considerable attention because they are synthetic precursors toward short segments of zigzag carbon nanotubes[1,2,3,4,5,6] and because they are typical cavitands processing well de ned cavities as a result of the intrinsic curvature of the oxanorbornene moieties.[7]. Reductive aromatization of this oxanorbornene-fused nanobox leads to observation of a new zigzag carbon nanobelt by high resolution mass spectroscopy.

Results

Conclusion