Isolation of CeLu2 N@Ih -C80 through a Non-Chromatographic, Two-Step Chemical Process and Crystallographic Characterization of the Pyramidalized CeLu2 N within the Icosahedral Cage

• Published in: Chemistry : a European journal Vol. 21; no. 29; pp. 10362 - 10368
• Main Authors: Stevenson, Steven, Thompson, Hannah R, Arvola, Kristine D, Ghiassi, Kamran B, Olmstead, Marilyn M, Balch, Alan L
• Format: Journal Article
• Language: English
• Published: Germany 13.07.2015
• Subjects: lutetium; endohedral fullerene; structure elucidation; cerium; purification
• ISSN: 1521-3765
• DOI: 10.1002/chem.201500915

By combining two chemical methods of purification, 4 mg of purified CeLu2 N@C80 was readily isolated from 500 mg of carbon soot extract without the use of recycling HPLC, a method which has previously been necessary to obtain pure samples of endohedral fullerenes. In stage 1, CeLu2 N@C80 was selectively precipitated by virtue of its low first oxidation potential (+0.01 V) and the judicious choice of MgCl2 as the Lewis acid precipitant. For stage 2, we used a stir and filter approach (SAFA), which employed the electron-rich NH2 groups immobilized on silica gel to selectively bind residual endohedrals and higher cage fullerenes that were contaminants from stage 1. Crystallographic analysis of CeLu2 N@C80 in the co-crystal CeLu2 N@Ih -C80 ⋅Ni(octaethylporphyrin)⋅2(toluene) reveals that the Ih -C80 cage is present with a pyramidalized CeLu2 N unit inside.