Selective extraction of fullerene C₆₀ by in situ interweaved AgNO₃ complex encapsulated C₆₀ molecular cages

With an in situ synthesized AgNO₃ complex molecular cage, icosahedral C₆₀ can be selectively extracted from fullerene mixture by a facial liquid–liquid interfacial precipitation, resulting in exclusive C₆₀ organometallic microcrystal (C₆₀/C₇₀ = 6/1). By exploiting its intrinsic insolubility against nonpolar solvent, the C₆₀ can be separated from the homologues, C₇₀, which contrarily is assembled through merely hydrophobic interaction and π-π stacking. The AgNO₃ complex encaged C₆₀ crystal was morphologically and structurally characterized by SEM, Raman and XRD spectra to revealing the underlying separation mechanism. The selective extraction efficiency (89.7%) was semiquantitatively characterized by combined optical spectroscopy and mass spectrometry, indicating a decent specificity of spontaneously formed molecular cage toward C₆₀ extraction. Thus, this discovery of a template-specific molecular cavity would pave the way to advance molecular imprinting technology using supramolecular array for fullerene separation, prevailing over the conventional "design-synthesis-performance" strategy by substantially reducing the laborious work and economic cost. Graphic abstract: