- 公益社団法人 有機合成化学協会
- 有機合成化学協会誌 (ISSN:00379980)
- vol.79, no.3, pp.224-233, 2021-03-01 (Released:2021-03-10)
Nonalternant hydrocarbons, which involve odd-membered rings, are an intriguing family for investigations of the structure-property relationship of π-conjugated carbocycles. Bicyclic nonalternant hydrocarbons, azulene, pentalene and heptalene, are the most fundamental molecules in a series of nonalternant hydrocarbons. Over the last 15 years, the chemistry of nonalternant hydrocarbons has experienced a remarkable renaissance mainly thanks to advances in synthetic methodologies. Ring-annulated nonalternant π-systems, in which some benzenoid rings are attached into the nonalternant frameworks, are the key players in their resurgence. The ring annulation impacts the electronic structures of nonalternant subunits, which modulates the HOMO-LUMO gap and creates perturbations in their inherent (anti)aromatic nature. The tunable, narrow HOMO-LUMO gap has offered rich studies into the electronic properties of open-shell characters and into their potential applications as functional organic optoelectronic materials. This article describes our recent studies on the synthesis and characterization of π-extended nonalternant hydrocarbons, containing azulene, pentalene and heptalene frameworks.