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

Abstract With an in situ synthesized AgNO 3 complex molecular cage, icosahedral C 60 can be selectively extracted from fullerene mixture by a facial liquid–liquid interfacial precipitation, resulting in exclusive C 60 organometallic microcrystal (C 60 /C 70  = 6/1). By exploiting its intrinsic insolubility against nonpolar solvent, the C 60 can be separated from the homologues, C 70 , which contrarily is assembled through merely hydrophobic interaction and π-π stacking. The AgNO 3 complex encaged C 60 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 C 60 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