From π-conjugated macrocycles to heterocycloarenes based on benzo[2,1-:3,4-']dithiophene (BDTh): size- and geometry-dependent host-guest properties.

π-Conjugated macrocycles have been highly attractive due to their challenging synthesis, fascinating aesthetic structure and unique physical and chemical properties. Although some progress has been made in synthesis, the study of π-macrocycles with different structural characteristics and supramolecular interactions still faces major challenges. In this paper, two new single-bond linked macrocycles (MS-4T/MS-6T) were reported, and the corresponding vinyl-bridged heterocycloarenes (MF-4T/MF-6T) were synthesized by the periphery fusion strategy.

From closed-shell edge-extended kekulenes to open-shell carbonylated cycloarene diradicaloid.

The precise synthesis of cycloarenes remains a challenging topic in both organic chemistry and materials science due to their unique fully fused macrocyclic π-conjugated structure. Herein, a series of alkoxyl- and aryl-cosubstituted cycloarenes (kekulene and edge-extended kekulene derivatives, K1-K3) were conveniently synthesized and an unexpected transformation of the anthryl-containing cycloarene K3 into a carbonylated cycloarene derivative K3-R was disclosed by controlling the temperature and gas atmosphere of the Bi(OTf)-catalyzed cyclization reaction. All their molecular structures were confirmed by single-crystal X-ray analysis.

Size-dependent properties and unusual reactivity of novel nonplanar heterocycloarenes.

The solution-phase synthesis of (hetero)cycloarenes with a well-defined size and geometric structure remains a challenging topic in organic chemistry and materials science. Herein, two novel nonplanar N,S-heterocycloarenes (PTZ1 and PTZ2) containing two/three alternate phenothiazine--phenanthrene units were conveniently synthesized. The smaller size heterocycloarene PTZ1 adopts a unique butterfly-shaped geometry and shows moderate supramolecular host-guest interactions with both fullerenes C and C; whereas the higher homologue PTZ2 has a saddle-shaped conformation and demonstrates no obvious encapsulation with C or C.