Purification method

A method for purifying a fullerene derivative represented by formula (1):

• wherein
• R1 represents an aryl group,
• R2 represents an aryl group,
• R3 represents a hydrogen atom,
• R4 represents a hydrogen atom,
• ring A represents a fullerene ring,
• n represents a number of 1 or more, and
• when n is 2 or more, in one or more pairs of monocyclic moieties represented by the following partial formula:
• one substituent selected from the group consisting of R2, R3, and R4 of one of the two monocyclic moieties is connected with one substituent selected from the group consisting of R2, R3, and R4 of the other of the two monocyclic moieties to form a tricyclic moiety,
• the method comprising step 1 of contacting a composition containing the fullerene derivative represented by formula (1) as a target product for purification and one or more impure fullerene compounds with an aluminum-containing inorganic porous adsorbent,
• wherein the aluminum-containing inorganic porous adsorbent is activated clay, and
• wherein the one or more impure fullerene compounds include at least one member selected from the group consisting of a fullerene derivative (i), an oxide of the fullerene derivative (i), a fullerene derivative (lm) represented by formula (1), an oxide of the fullerene derivative (lm) represented by formula (1), a fullerene C60, and an oxide of the fullerene C60,
• wherein the fullerene derivative (i) is represented by formula (i):
• wherein
• R1 represents an organic group,
• R3 represents a hydrogen atom,
• R4 represents a hydrogen atom, and
• ring A represents a fullerene ring, and wherein the fullerene derivative (lm) is represented by formula (1):
• wherein
• R1 represents an organic group,
• R2 represents an organic group,
• R3 represents a hydrogen atom or an organic group,
• R4 represents a hydrogen atom or an organic group,
• ring A represents a fullerene ring, and
• n is a number of 2 or more.