Probing the binding sites and coordination limits of buckybowls in a solvent-free environment: Experimental and theoretical assessment

Synthesis of Sumanene and Related Buckybowls

“…In contrast, Amaya et al reported a Fe(© 6 -sumanene) complex as the first example of an endo-coordinated metal complex at a concave face ( Scheme 14). 15 In the presence of Al powder and AlCl 3 , heating of sumanene (1) and ferrocene at 120°C without solvent, followed by exchange of the counter anion with NH 4 PF 6 , gives [CpFe(© 6 -endo-sumanene)]PF 6 53a in 91% yield. X-ray crystallographic analysis of 53a shows that iron is bound on the side benzene ring at the concave face.…”

“…Higashibayashi et al further advanced this synthetic strategy in 2008 to generate a selective synthesis of C 3 symmetric trisubstituted sumanene, as well as the first enantioselective synthesis of a chiral buckybowl. 5 As mentioned in the next chapter, in the preparation of C 3 symmetric derivatives, the contamination by regioisomers is difficult to avoid in the selective introduction of substituents at aromatic positions of sumanene (1). The synthesis of these derivatives is based on the transformation of a C 3 symmetric syn-tris(norborneno)benzene with functional groups that enable introduction of substituents (Scheme 3).…”

“…Recent advances in buckybowl chemistry have also led to the application of buckybowls to novel materials. This review summarizes the recent developments in the synthesis of sumanene (1) and its derivatives, including heterasumanenes, focusing especially on solution-phase syntheses. The synthetic strategies for the construction of sumanene and heterasumanene skeletons are presented in the first chapter and the functionalization and derivatization of sumanenes are discussed in the second chapter.…”

Chiral Buckybowl Molecules

“…The conjugated bowl structure itself possesses the chirality, such as π-extended buckybowls, e.g., hemifullerene 3; bowl chirality caused by introduction of one or more substituents on the rim of the buckybowl, e.g., trimethylsumanene 4; and bowl chirality originated from the introduction of heteroatom into the π-bowl carbon skeleton, e.g., triazasumanene 5. While several buckybowl-related reviews have been published in recent years [6,[39][40][41][42][43][44], most of them focused on the synthetic strategy and derivation method. Only a few publications involve the stereochemistry or chirality of the buckybowls.…”

“…A better understanding of bowl chirality will help researchers find a good way to control the chiral self-assembly of carbon nanotubes (CNTs) or fullerenes, which have already exhibited exciting potential as next-generation functional materials [28][29][30][31][32][33][34][35][36][37][38]. While several buckybowl-related reviews have been published in recent years [6,[39][40][41][42][43][44], most of them focused on the synthetic strategy and derivation method. Only a few publications involve the stereochemistry or chirality of the buckybowls.…”