Peroxide‐Mediated Selective Cleavage of [60]Fullerene Skeleton Bonds: Towards the Synthesis of Open‐Cage Fulleroid C₅₅O₅

Abstract

Replacement of a pentagon in [60]fullerene with five oxygen atoms yields the open-cage compound C55O5 with five carbonyl groups on the rim of the orifice. Our attempts to synthesize such a target molecule starting from C60 have led us to prepare the fullerene-mixed peroxides such as C60(OO-t-Bu)6 with all the peroxo addends surrounding the same pentagon. Further investigations of the peroxide chemistry have generated various open-cage fullerene derivatives, including the carbon monoxide encapsulated endohedral compound CO@C59O6. This Personal Account mainly discusses peroxide-based processes resulting in selective cleavage of the fullerene skeleton bonds.

[60]Fullerene‐Based Macrocycle Ligands

“…In ar esearch proposal back in 2000, Gan proposed the molecule 15 C 55 O 5 by replacing ap entagoni nC 60 with five oxygen atoms (Scheme 7). [14] Arrangemento ft he five carbonyl groups is reminiscent of the cucurbit [5]uril. Su et al performed DFT calculations for C 55 O 5 .…”

Synthesis of C70‐Based Fluorophores through Sequential Functionalization to Form Isomerically Pure Multiadducts

“…In conclusion, multiaddition is shown to be an effective method for separating the ellipsoidal C 70 p system into various fluorophores.T he octamethoxy adduct C 70 (OMe) 8 could be readily prepared on ag ram scale and is shown to be av ersatile precursor for selective functionalization as ar esult of the relatively stable fullerene C 70 ÀOMe bond and moderate steric hindrance from the OMe groups.T he emission wavelength of C 70 derivatives can be fine-tuned over awide range from blue to red. In addition, click reactions may be applied to attach functional groups to the fluorophore.…”

“…[8] In an effort to prepare C 70 open-cage derivatives,w ei nvestigated the reactivity of C 70 (OOtBu) 10 [9] and found that the peroxo groups in this compound show very poor selectivity in C 70 cage-opening reactions.W et hen turned our attention to the analogous methoxyl adducts C 70 (OMe) 8/10 with all the methoxyl groups located on the equatorial region. Theo ctaadduct C 70 (OMe) 8 was prepared by treating C 70 Cl 8 [10] with methanol in the presence of silver perchlorate in excellent yield (Scheme 1). Under similar conditions,t he decaadduct C 70 (OMe) 10 was obtained in moderate yield from C 70 Cl 10 .…”

“…Under similar conditions,t he decaadduct C 70 (OMe) 10 was obtained in moderate yield from C 70 Cl 10 . [10] Since the yield of C 70 Cl 8 is quantitative from C 70 and ICl, C 70 (OMe) 8 could be readily prepared on ag ram scale,a nd served as the starting material for further functionalization.…”

Synthesis of Metal Complexes with an Open‐Cage Fullerene as the Ligand

“…[5] Recently, an iridium pyrrolidinofullerenec omplex was prepared [3e] and was shown to act as an effective hydrogen-transfer catalyst. [6] Selective cleavage of fullerene skeleton bondsw ithin al ocal area results in open-cagef ullerenes, [7] which could also form metal complexes with heteroatoms on edge of the structure. Due to the unique spherical p system, metal complexesw ith open-cage fullerene as ligandsa re attractive targets in order to explore potentiala pplications.…”