"Broken-hearted" carbon bowl via electron shuttle reaction: energetics and electron coupling

• Published in: Chemical science (Cambridge) Vol. 12; no. 19; pp. 6600 - 6606
• Main Authors: Leith, Gabrielle A, Rice, Allison M, Yarbrough, Brandon J, Kittikhunnatham, Preecha, Mathur, Abhijai, Morris, Nicholas A, Francis, Megan J, Berseneva, Anna A, Dhull, Poonam, Adams, Richard D, Bobo, M Victoria, Vannucci, Aaron A, Smith, Mark D, Garashchuk, Sophya, Shustova, Natalia B
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 08-04-2021; The Royal Society of Chemistry
• Subjects: Carbon; Charge transfer; Chemistry; Coupling; Crystallography; Electrons; Polycyclic aromatic hydrocarbons; Tetracyanoquinodimethane; Topology
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d0sc06755e

Unprecedented one-step C[double bond, length as m-dash]C bond cleavage leading to opening of the buckybowl (π-bowl), that could provide access to carbon-rich structures with previously inaccessible topologies, is reported; highlighting the possibility to implement drastically different synthetic routes to π-bowls in contrast to conventional ones applied for polycyclic aromatic hydrocarbons. Through theoretical modeling, we evaluated the mechanistic pathways feasible for π-bowl planarization and factors that could affect such a transformation including strain and released energies. Through employment of Marcus theory, optical spectroscopy, and crystallographic analysis, we estimated the possibility of charge transfer and electron coupling between "open" corannulene and a strong electron acceptor such as 7,7,8,8-tetracyanoquinodimethane. Alternative to a one-pot solid-state corannulene "unzipping" route, we reported a nine-step solution-based approach for preparation of novel planar "open" corannulene-based derivatives in which electronic structures and photophysical profiles were estimated through the energies and isosurfaces of the frontier natural transition orbitals.