Pentadecker Supramolecules with a Lithium Alkoxo Nanobelt Sandwiched between Two Highly Charged Buckybowl Surfaces

Zabula, Alexander V.; Spisak, Sarah N.; Filatov, Alexander S.; Petrukhina, Marina A.

doi:10.1002/ange.201206936

Cited by 21 publications

(2 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have previously seen that Li-induced reduction of corannulene in DME is accompanied by side-reactions, affording lithium alkoxo-clusters. [22] To avoid these complications, the reaction time should be minimized. However, even with the short reaction times, the in situ 7 Li NMR measurements for the mixed Li/K systems in DME showed a variety of peaks owing to the above intrinsic problems.…”

Section: Dedicated To Professor Roald Hoffmann On the Occasion Of Hismentioning

confidence: 99%

Clamshell Opening in the Mixed‐Metal Supramolecular Aggregates Formed by Fourfold Reduced Corannulene for Maximizing Intercalated Metal Content

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Dedicated To Professor Roald Hoffmann On the Occasion Of Hismentioning

confidence: 99%

Clamshell Opening in the Mixed‐Metal Supramolecular Aggregates Formed by Fourfold Reduced Corannulene for Maximizing Intercalated Metal Content

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…38 The reduction of corannulene with an excess of Li metal in dimethoxyethane (DME) initially leads to the generation of the [1 4− /Li 5 /1 4− ] 3− aggregate. 39 However, in contrast to THF, prolonged reaction time in DME results in Li-induced solvent fragmentation, producing polynuclear lithium alkoxides. The latter can be entrapped between the tetraanions of 1 to form unprecedented multilayered supramolecular products with 12 encapsulated lithium ions, [1 4− /Li 6 /(OR) 6 /Li 6 /1 4− ] 2− (Figure 4), as revealed crystallographically.…”

Section: All-lithium Sandwichesmentioning

confidence: 99%

Record Alkali Metal Intercalation by Highly Charged Corannulene

et al. 2018

Self Cite

View full text Add to dashboard Cite

The need for advanced energy storage technologies demands the development of new functional materials. Novel carbon-rich and carbon-based materials of different structural topologies attract significant attention in this regard. Attractive systems include a unique class of bowl-shaped polycyclic aromatic hydrocarbons that map onto fullerene surfaces and are thus often referred to as fullerene fragments, buckybowls, or π-bowls. Importantly, carbon bowls are able to acquire multiple electrons in stepwise reduction reactions producing sets of successively reduced carbanions. The resulting negatively charged π-bowls exhibit unique supramolecular assembly and metal intercalation patterns that only recently have begun to be uncovered. First, we have resolved the long-standing mystery behind the supramolecular structure formed by a highly reduced fullerene fragment called corannulene (CH) with multiple lithium ions, using X-ray crystallography coupled with NMR spectroscopy and theoretical calculations. This work provided a new paradigm for lithium ion intercalation between the curved carbon π-surfaces and facilitated understanding of the lithium ion storage mechanism in carbonaceous matrices. Next, we have initiated a new research direction, an investigation of the mixed alkali metal reduction reactions using bowl-shaped corannulene as a remarkable multielectron reservoir and unique ligand with open convex and concave π-surfaces. As a result, we have revealed the cooperative effect of lithium with heavier Group 1 metals in reduction and self-assembly processes of corannulene. Moreover, we have discovered a new class of organometallic supramolecules having heterometallic cores with high nuclearity and charge such as LiM and LiM (M = K, Rb, and Cs) sandwiched between two tetrareduced corannulene decks. The resulting triple-decker supramolecular assemblies, fully characterized by X-ray diffraction and spectroscopic methods, were found to exhibit a record ability of the highly charged corannulene π-surfaces to be fully engaged in intercalation of multiple metal ions. Based on this unique ability, curved π-ligands with extended carbon frameworks are expected to show remarkable potential for alkali metal storage compared to flat polycyclic arenes. Notably, a previously unseen mode of internal lithium binding revealed in the heterobimetallic sandwiches is accompanied by unprecedented negative shifts (up to -25 ppm) in Li NMR spectra. Based on in-depth analysis of NMR data, augmented by DFT calculations, we have rationalized the observed experimental trends and proposed the mechanism of stepwise alkali metal substitution reactions. Furthermore, we have correlated the origin of the recordLi NMR shifts with unique electronic structures of these novel supramolecular aggregates. Herein we present comprehensive analysis of unusual structural and electronic features of remarkable heterometallic self-assemblies formed by tetrareduced corannulene, using a wealth of our recent experimental and computational results. This work uncovers u...

show abstract