The acceleration effect of water in the selective complexation of fullerenes with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was investigated. Although selective complexation with DBU is useful for large-scale [60]fullerene separation from a fullerene mixture, the complexation is too slow for practical application at ambient temperature without the addition of water. In the presence of a small amount of water, the complexation accelerated considerably, and a pure [60]fullerene solution was readily obtained by complexation at 20 degrees C. The procedure was easily scaled up, and 1.3 kg of pure [60]fullerene was obtained from 3.0 kg of the fullerene mixture.