A strong DNA cleavage property switched by photo irradiation was found for 9-anthracenecarboxylic acid substituted gem-difluorocyclopropane derivatives; in particular, a clear contrast in the activity was observed between the enantiomers of (S,S)- and (R,R)-3-aminomethyl-2,2-difluorocyclopropylmethyl 9-anthracenecarboxylate. (C) 2006 Elsevier B.V. All rights reserved.