Cylindrical and Conical Conjugated Nanobelts by Longitudinal Extension of Cycloparaphenylene and Their Double-Walled Assembly.

Constructing carbon nanotubes and related segments with atomic precision remains challenging, despite significant advances, including cycloparaphenylene (CPP), carbon nanobelts, and phenine nanotubes. Here, we report three conjugated nanobelts (-) constructed by longitudinal π-extension of CPP with rings of the same, smaller, or larger size. Each nanobelt comprises three fused aromatic units bridging two axial CPP rings, which mediate the intermolecular assembly.

π-Extension of a Multiple Resonance Core: Double Helical and Heptagon-Embedded Nanographenes.

Multiple resonance (MR) boron-nitrogen doped polycyclic aromatic hydrocarbons (BN-PAHs) have shown compelling thermally activated delayed fluorescence (TADF), surpassing those of their hydrocarbon analogues. However, the structural variety of π-extended BN-PAHs remains narrow. In this study, we synthesized three double helical BN-doped nanographenes (BN-NGs), 2 a-2 c, and three heptagon-embedded BN-NGs, 1 a-1 c, by π-extension of the MR core.

Helical Nanographenes Bearing Pentagon-Heptagon Pairs by Stepwise Dehydrocyclization.

The incorporation of pentagon-heptagon pairs into helical nanographenes lacks a facile synthetic route, and the impact of these pairs on chiroptical properties remains unclear. In this study, a method for the stepwise construction of pentagon-heptagon pairs in helical nanographenes by the dehydrogenation of [6]helicene units was developed. Three helical nanographenes containing pentagon-heptagon pairs were synthesized and characterized using this approach.

Nanographene with a Nitrogen-Doped Cavity.

Nitrogen-doped cavities are pervasive in graphenic materials, and represent key sites for catalytic and electrochemical activity. However, their structures are generally heterogeneous. In this study, we present the synthesis of a well-defined molecular cutout of graphene featuring N-doped cavity.

Phenylene segments of zigzag carbon nanotubes synthesized by metal-mediated dimerization.

Well-studied cycloparaphenylenes (CPPs) correspond to the simplest segments of armchair CNTs, whereas the corresponding macrocyclic oligophenylene strip of zigzag CNTs is still missing. Herein, we present two series of conjugated macrocycles (CM2PP and CN2PP) containing two -phenylene or 2,7-naphthylene units facing each other in the strip. CM2PP and CN2PP can be regarded as the shortest cyclic primitive segments of zigzag CNTs.

Nanographene with Multiple Embedded Heptagons: Cascade Radical Photocyclization.

Although heptagons are widely found in graphenic materials, the precise synthesis of nanocarbons containing heptagons remains a challenge, especially for the nanocarbons containing multiple-heptagons. Herein, we show that photo-induced radical cyclization (PIRC) can be used to synthesize multi-heptagon-embedded nanocarbons. Notably, a nanographene containing six heptagons (1) was obtained via a six-fold cascade PIRC reaction.

Efficient resolution of venlafaxine and mechanism study via X-ray crystallography.

Numbers of resolving factors were investigated to improve resolution of venlafaxine 1. An effective resolving agent, O,O'-di-p-toluoyl-(R, R)-tartaric acid 2, was screened using similar method of 'Dutch resolution' from tartaric acid derivatives. The resolution efficiency was up to 88.