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 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 pi-pi stacking. The AgNO3 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. [GRAPHICS]

Automated summary

By in situ synthesis of an AgNO3 complex molecular cage, selective extraction of icosahedral C-60 has been achieved, resulting in exclusive C-60 organometallic microcrystals with a ratio of C-60/C-70 = 6/1. The method utilizes the intrinsic insolubility of C-60 against nonpolar solvents to separate it from homologues like C-70, showcasing decent specificity and efficiency. Structural characterizations and efficiency evaluations demonstrate the feasibility and advantages of this separation technique.