title: A main group metal sandwich: five lithium cations jammed between two corannulene tetraanion decks.
abstract: Lithium-coordinated polyaromatic anions such as tetrareduced corannulene, C(20)H(10)(4-) (1(4-)), are useful substrates to model and ultimately improve the graphitic electrodes in lithium-ion (Li(+)) batteries. Previous studies suggested that 1(4-) forms dimers encasing four Li(+) ions in solution. Here, we report a single-crystal x-ray diffraction analysis confirming the formation of a sandwich-type supramolecular aggregate with a high degree of alkali metal intercalation. In contrast to the prior model, our data reveal that five Li(+) ions are sandwiched between the two tetrareduced corannulene decks, and (7)Li nuclear magnetic resonance spectroscopy delineates a conserved structure in tetrahydrofuran solution. Remarkably, the sandwich is robust in both solution and solid states even in the presence of crown ethers that compete for Li(+) coordination. These results should help elucidate Li(+) intercalation motifs between curved carbon surfaces more broadly.
authors.affiliation: University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Zabula
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Filatov
authors.forename: Sarah N
authors.initials: SN
authors.lastname: Spisak
authors.forename: Andrey Yu
authors.initials: AY
authors.lastname: Rogachev
authors.forename: Marina A
authors.initials: MA
authors.lastname: Petrukhina