Macrocycles composed of biphenylene and butadiyne units with antiaromatic character.

ABSTRACT: Herein, we report the synthesis and characterization of π-conjugated macrocycles, with diameters over 2.4 nanometers, composed of biphenylene and butadiyne units. Specifically, biphenylene-2,7-diyl-butadiyne-1,4-diyl (BB) macrocycles were synthesized via the intermolecular Hay coupling reaction of a 2,7-diethynylbiphenylene derivative. The BB macrocycles exhibited absorption bands extending up to ∼600 nm and emitted red luminescence. Moreover, scanning tunneling microscopy observations revealed that the BB macrocycles formed self-assembled molecular networks at the liquid-graphite interface, showing higher tunneling efficiency. The BB macrocycles exhibited high energy levels of the highest occupied molecular orbitals and narrow energy gaps due to the elongated π-electron conjugation

SUBMITTER: Nagayama S 

PROVIDER: S-EPMC12394915 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature