Buckybowl-Based Nanocarbons: Synthesis, Properties, and Applications

Area of Science:

• Materials Science
• Organic Chemistry
• Nanotechnology

Background:

• Introduction of five-membered rings into polycyclic aromatic hydrocarbons (PAHs) creates strain, resulting in bowl-shaped structures known as buckybowls.
• Buckybowls possess unique properties like pyramidalized sp2 carbon atoms, low-lying LUMO, and surface charge stabilization, driving interest in their applications.
• Functionalization and π-extension of buckybowls are key strategies for developing diverse nanostructures with tunable properties, but limited suitable frameworks and synthetic challenges hinder progress.

Purpose of the Study:

• To describe recent advancements in the synthesis of buckybowls and buckybowl-based nanocarbons.
• To explore the use of specific buckybowl units (DIP, PP, TPP, corannulene) as platforms for functionalization and π-extension.
• To investigate the impact of peripheral substituents on solubility, energy levels, and crystal packing, and their conversion into diverse nanocarbon structures.

Main Methods:

• Employed diindeno[4,3,2,1-fghi:4',3',2',1'-opqr]perylene (DIP), pyracyleno[6,5,4,3,2,1-pqrstuv]pentaphene (PP), tetracyclopenta[cd,fg,jk,mn]pyrene (TPP), and corannulene as core structural units.
• Utilized general bottom-up approaches to synthesize buckybowl derivatives functionalized with peripheral alkynyl and aryl groups.
• Converted functionalized buckybowls into π-extended nanocarbons, including doubly curved, rippled, and chiral structures.

Main Results:

• Synthesized a range of buckybowl derivatives and π-extended nanocarbons with diverse topologies, including chiral structures with high enantiomerization barriers.
• A rippled nanocarbon fused to the TPP core demonstrated attractive electronic, magnetic, and mechanical properties, amenable to further functionalization.
• Developed buckybowl-based nanocarbons that form highly ordered host-guest systems with fullerenes, showing tunable binding constants and potential for device applications.

Conclusions:

• The developed synthetic strategies enable access to a wider structural diversity of buckybowl-based nanocarbons, overcoming previous limitations.
• Buckybowl-based nanocarbons exhibit promising performance as organic semiconductors in organic field-effect transistors (OFETs) with high mobilities.
• These nanocarbons also show potential as photothermal materials with high conversion efficiencies, highlighting their versatility.