Open‐Cage Fullerene as a Selective Molecular Trap for LiF/[BeF]⁺

Abstract

The insertion of ionic compounds into open‐cage fullerenes is a challenging task due to the electropositive nature of the cavity. The present work reports the preparation of an open‐cage C60 derivative with a hydroxy group pointing towards the centre of the cavity, which can coordinate to a metal cation, thus acting as a bait/hook to trap the metal cation such as the lithium cation in neutral LiF and the beryllium cation in the cationic [BeF]+ species. Other metal salts could not be inserted under similar conditions. The structure of MF in the cage was unambiguously determined by single‐crystal X‐ray diffraction. Owing to its tendency to undergo polycoordination, Li+ monomer salts have not been isolated before, despite extensive research on Li bonds. The present results provide a unique example of a Li bond.

Open-Cage Fullerene as a Macrocyclic Ligand for Na, Pt, and Rh Metal Complexes

“…We have recently reported the C 60 open-cage derivative 1 through the fullerene-mixed peroxide method and its reaction with 1,2-benzenediamine to form a new open-cage complex capable of encapsulating various guest molecules including LiF. 22 Further oxidation of the vicinal triol moiety under the Malaprade oxidation condition resulted in compound H [2] with a carboxylic group above the expanded orifice (Scheme 1). The corresponding sodium salt, Na [2], was isolated when NaIO 4 was added together with HIO 4 in about 1:1 ratio.…”

Construction of a 21‐Membered‐Ring Orifice on [60]Fullerene

“…The mass spectrometric analysis of the product (8) confirmed its molecular ion peak at m/z 1265.3362, being characterizable to [2 + HNMe 2 ] *À , in which HNMe 2 might be generated from TDAM through a thermal decomposition. [2,20] In this reaction, one of the C-CO bonds was cleaved to form C(sp 2 )À H and CONMe 2 while the reaction site was determined by long-range 1 HÀ 13 C correlation. During the reaction, the ring-atom count varied from 20 (2) to 21 (8), being associated with the removal of one caged carbon atom as an amide group.…”

“…[4] A huge orifice is also useful for trapping a chemically labile species such as H 2 O 2 under mild conditions (C) as shown by Lu, Gan, and co-workers in 2018. [12] The raise in awareness to gain huge orifices led to the successive reports on 21-membered-ring orifices recently (D [13] and E [14] ). The latter one was prepared from F, [15] which is structurally related to A while F has a reactive carbonyl group on the 20-membered-ring orifice.…”

A quest for ideal electric field-driven MX@C70 endohedral fullerene memristors: which MX fits the best?

“…[29][30][31][32] Although the large-scale synthesis of the MX@C 70 systems studied here seems to be inaccessible at the moment, molecular surgery methods come across as a step in the right direction. [33][34][35][36] Very recently, Gao et al 37 successfully performed insertion of LiF and [BeF] + into an open-cage C 60 fullerene. This was enabled thanks to the interaction of the 'bait' hydroxy groups at the rim of the orifice with the metal atom.…”

“…This was enabled thanks to the interaction of the 'bait' hydroxy groups at the rim of the orifice with the metal atom. 37 Because the subsequent closing of the open-cage fullerene is sometimes possible, 33,38 the suggested MX@C 70 species may be very probably eventually synthesized and employed in molecular circuits.…”