To provide a carbon cluster derivative monoanion or dianion in which 10 organic substituent group is added to fullerene C60 and a metal complex in which the anion is bound to a metal in η5 style, capable of solving problem of low solubility characteristic to fullerene and excellent in electron conductivity and photochemical characteristic.

This invention relates to a carbon cluster derived from fullerene of general formula I or III (R and R, R and R' and R' and R' each represent organic groups which may be same or different; Y represents CN or H), hydrogen substituent thereof and a metal complex in which the anion is bound to a metal in η5 style.