Corannulene

Corannulene is a polycyclic aromatic hydrocarbon with the chemical formula C₂₀H₁₀. It is notable for its unique bowl-shaped structure, making it a subject of interest in the field of organic chemistry and materials science. Corannulene is one of the first discovered fragments of fullerene, molecules composed entirely of carbon, in the form of a hollow sphere, ellipsoid, or tube. Fullerenes, including corannulene, have been studied for their potential applications in various fields such as organic electronics, photovoltaics, and nanotechnology.

Structure and Properties

Corannulene consists of a five-membered ring surrounded by five six-membered rings, forming a concave bowl shape. This curvature distinguishes it from the planar structures of other polycyclic aromatic hydrocarbons (PAHs) like naphthalene, anthracene, and pyrene. The unique geometry of corannulene introduces strain into the molecule, which affects its electronic and physical properties.

The bowl depth of corannulene is approximately 0.5 nm, and it has a diameter of about 1.2 nm. Its bowl-shaped structure can undergo a process known as "bowl-to-bowl inversion," which is a dynamic process where the molecule inverts to an equivalent geometry, akin to an umbrella turning inside out in a strong wind.

Synthesis

The synthesis of corannulene involves multiple steps, starting from readily available organic compounds. The first successful synthesis was reported by Barth and Lawton in 1966. Since then, various synthetic routes have been developed to improve the yield and efficiency of corannulene production. These methods often involve cyclodehydrogenation reactions, where precursor molecules are fused together and hydrogen atoms are removed to form the corannulene structure.

Applications

Due to its unique structure and properties, corannulene has potential applications in various fields. In organic electronics, it can be used as a component of organic semiconductors due to its ability to transport charge. In nanotechnology, corannulene molecules can serve as building blocks for constructing larger nanostructures. Additionally, its bowl-shaped structure is of interest for the development of molecular containers that can encapsulate smaller molecules, potentially useful in drug delivery systems.

Research

Research on corannulene is ongoing, with scientists exploring its properties, synthesis, and potential applications. Studies have investigated its ability to form supramolecular assemblies, interact with fullerenes, and its behavior in organic electronic devices. The understanding of corannulene and related molecules continues to expand, contributing to the development of new materials and technologies.

See Also

• Fullerene
• Polycyclic aromatic hydrocarbon
• Organic electronics
• Nanotechnology