Belt‐Shaped Cyclonaphthylenes

Abstract

The recent development of cyclo-para-phenylenes has demonstrated the feasibility of radial π systems in nanohoop structures, especially in the crystalline state. However, in contrast to macrocyclic molecules with benzene units, which have a several-decades-long history, macrocycles composed solely of naphthylene units (the smallest acene) have been much less explored. Although two examples of cyclonaphthylenes have been reported to date, neither possesses a radial π system. We herein report the first example of belt-shaped cyclonaphthylenes with curved π systems. The molecule, [8]cyclo-amphi-naphthylene, is linked at the 2,6-positions of the naphthylene units, thus affording belt-shaped molecules. Although the molecular structures are flexible, which allows for rotation of the naphthylene units in solution, they can be rigidified with the aid of methylene bridges to afford persistent molecular structures in solution.

[4]Cyclo‐N‐ethyl‐2,7‐carbazole: Synthesis, Structural, Electronic and Charge Transport Properties

“…[30] As the synthesis of nanorings is ac entral point in the field, and particularly,i fa ne lectronic application is envisaged, synthetic investigations (screening of temperature, solventa nd reactiont ime, see Ta ble S1) for both the transmetallation and reductive elimination steps were performed. Thus, the reductivee limination step, which is unfavoured because of the strain energy,c an be assisted by increasing both the temperature (by using o-dichlorobenzene as previously reportedb yI sobe and co-workersf or cyclonaphthylene nanohoops [31] )a nd reactiont ime. Thus, the reductivee limination step, which is unfavoured because of the strain energy,c an be assisted by increasing both the temperature (by using o-dichlorobenzene as previously reportedb yI sobe and co-workersf or cyclonaphthylene nanohoops [31] )a nd reactiont ime.…”

Stereoisomerism in Nanohoops with Heterogeneous Biaryl Linkages of E/Z- and R/S-Geometries

“…11,13,20 Through our studies on the stereoisomerism and molecular shapes, we may now categorize the nanohoop structures into three major types: (1) cylinder/tube/belt shapes, (2) fluctuating shapes, and (3) non-belt shapes. 10−12,19,20 We hope that the unique cyclostereoisomerism found in this study may deepen our understanding of nanohoop structural chemistry and may also facilitate the expansion of its scope to allied fields of chemistry.…”

“…In the belt-shaped nanohoops, the restricted biaryl rotations originated from macrocyclic ring strains to result in anomalous atropisomerism: 10−13,19,20 in the absence of steric repulsions, the biaryl linkages possessing 2,2′-binaphthyl structures in [6]CaNAP have been constrained at the coplanar, E/Z geometries. Conventionally, however, atropisomerism of biaryls such as 1,1′-binaphthyl was generated by steric repulsions between ortho -substituents, and the chirality emerged from the non-coplanar, R/S biaryl geometries.…”

Narrowing Segments of Helical Carbon Nanotubes with Curved Aromatic Panels

“…[5] This study demonstrated that amethod to narrow the chiral cylinders can be devised by adopting curved arylene panels in the Pt-mediated macrocyclization. [10][11][12][13][14][15]24,31] Width variations of the chiral molecular cylinders allowed us to deepen our understanding of their unique chiroptical properties. [18] Notably,atransient cyclic current can be induced on the chiral cylinders upon photo-excitation, which intensifies current-induced magnetic dipole moments in aw idth-dependent manner.…”

“…[4] Contrarily,s egments with chiral angles other than q = 308 8 are much less explored and still scarce. [11,[13][14][15] We previously designed and synthesized the first helical CNT segments,that is,[4]cyclo-2,8-chrysenylenes ([4]CC), [11] and revealed the anomalous properties of helical (P)/(M)-(12,8)-congeners (q = 23.48 8), such as unique chiroptical behaviors (Figure 1). [5,16] However,e xamples of rigid chiral congeners are still scarce, [5] and to deepen our understanding of the unique cylinder chirality,aseries of congeners with varying cylinder widths and an identical chiral angle are indispensable.…”