Selective Complexation and Reactivity of Metallic Nitride and OxoMetallic Fullerenes with Lewis Acids and Use as an Effective Purification Method

摘要

Metallic nitride fullerenes (MNFs) and oxometallic fullerenes (OMFs) react quickly with an array of Lewis acids. Empty-cage fullerenes are largely unreactive under conditions used in this study. The reactivity order is Sc4O2@Ih-C80 > Sc3N@C78 > Sc3N@C68 > Sc3N@D5h-C80 > Sc3N@Ih-C80. Manipulations of Lewis acids, molar ratios and kinetic differences within the family of OMF and MNF metallofullerenes are demonstrated in a selective precipitation scheme, which can be used either alone for purifying Sc3N@Ih-C₈₀ or combined with a final HPLC pass for Sc₄O₂@I_h-C₈₀, Sc₃N@D_5h-C₈₀, Sc₃N@C₆₈, or Sc₃N@C₇₈. The purification process is scalable. Analysis of experimental rate constants versus electrochemical band gap explains the order of reactivity among the OMF and MNFs.